plotpy/

plot.rs

use super::{call_python3, generate_list_quoted, vector_to_array, AsVector, Legend, StrError, SuperTitleParams};
use num_traits::Num;
use std::ffi::OsStr;
use std::fmt::Write;
use std::fs::{self, File};
use std::io::Write as IoWrite;
use std::path::Path;

const DEFAULT_PYTHON_EXE: &str = "python3";

/// Defines the trait used by Plot to add graph entities
pub trait GraphMaker {
    /// Returns the text buffer with Python3 commands
    fn get_buffer<'a>(&'a self) -> &'a String;

    /// Clear the text buffer with Python commands
    fn clear_buffer(&mut self);
}

/// Driver structure that calls Python
///
/// # Examples
///
/// ## Drawing curves
///
/// ```
/// use plotpy::{linspace, Curve, Plot, StrError};
///
/// fn main() -> Result<(), StrError> {
///     // generate (x,y) points
///     let n = 11;
///     let x = linspace(-1.0, 1.0, n);
///     let y1 = x.clone();
///     let y2: Vec<_> = x.iter().map(|v| f64::abs(*v)).collect();
///     let y3: Vec<_> = x.iter().map(|v| f64::exp(1.0 + *v) - 1.0).collect();
///     let y4: Vec<_> = x.iter().map(|v| f64::sqrt(1.0 + *v)).collect();
///
///     // configure and draw curves
///     let mut curve1 = Curve::new();
///     let mut curve2 = Curve::new();
///     let mut curve3 = Curve::new();
///     let mut curve4 = Curve::new();
///     curve1.set_label("y = x");
///     curve2.set_label("y = |x|").set_line_color("#cd0000");
///     curve3.set_label("y = exp(1+x)-1").set_line_color("#e79955");
///     curve4.set_label("y = sqrt(1+x)").set_line_color("#b566ab");
///     curve1.draw(&x, &y1);
///     curve2.draw(&x, &y2);
///     curve3.draw(&x, &y3);
///     curve4.draw(&x, &y4);
///
///     // configure plot
///     let mut plot = Plot::new();
///     plot.set_super_title("FOUR CURVES", None).set_gaps(0.35, 0.5);
///
///     // add curve to subplot
///     plot.set_subplot(2, 2, 1)
///         .set_title("first")
///         .add(&curve1)
///         .grid_labels_legend("x", "y")
///         .set_equal_axes(true);
///
///     // add curve to subplot
///     plot.set_subplot(2, 2, 2)
///         .set_title("second")
///         .add(&curve2)
///         .grid_labels_legend("x", "y");
///
///     // add curve to subplot
///     plot.set_subplot(2, 2, 3)
///         .set_title("third")
///         .add(&curve3)
///         .set_range(-1.0, 1.0, 0.0, 6.0)
///         .grid_labels_legend("x", "y");
///
///     // add curve to subplot
///     plot.set_subplot(2, 2, 4)
///         .set_title("fourth")
///         .add(&curve4)
///         .grid_labels_legend("x", "y");
///
///     // save figure
///     plot.save("/tmp/plotpy/doc_tests/doc_plot.svg")?;
///     Ok(())
/// }
/// ```
///
/// ![doc_plot.svg](https://raw.githubusercontent.com/cpmech/plotpy/main/figures/doc_plot.svg)
///
/// ## Drawing an image from data and setting the ticks
///
/// See [Matplotlib example](https://matplotlib.org/stable/gallery/images_contours_and_fields/image_annotated_heatmap.html)
///
/// ```
/// use plotpy::{Image, Plot, Text, StrError};
///
/// fn main() -> Result<(), StrError> {
///     // data
///     let vegetables = [
///         "cucumber",
///         "tomato",
///         "lettuce",
///         "asparagus",
///         "potato",
///         "wheat",
///         "barley",
///     ];
///     let farmers = [
///         "Farmer Joe",
///         "Upland Bros.",
///         "Smith Gardening",
///         "Agrifun",
///         "Organiculture",
///         "BioGoods Ltd.",
///         "Cornylee Corp.",
///     ];
///     let harvest = [
///         [0.8, 2.4, 2.5, 3.9, 0.0, 4.0, 0.0],
///         [2.4, 0.0, 4.0, 1.0, 2.7, 0.0, 0.0],
///         [1.1, 2.4, 0.8, 4.3, 1.9, 4.4, 0.0],
///         [0.6, 0.0, 0.3, 0.0, 3.1, 0.0, 0.0],
///         [0.7, 1.7, 0.6, 2.6, 2.2, 6.2, 0.0],
///         [1.3, 1.2, 0.0, 0.0, 0.0, 3.2, 5.1],
///         [0.1, 2.0, 0.0, 1.4, 0.0, 1.9, 6.3],
///     ];
///
///     // draw image
///     let mut img = Image::new();
///     img.draw(&harvest);
///
///     // set tick labels
///     let mut plot = Plot::new();
///     let ticks: Vec<_> = (0..vegetables.len()).into_iter().collect();
///     plot.add(&img)
///         .set_rotation_ticks_x(45.0)
///         .set_ticks_x_labels(&ticks, &farmers)
///         .set_ticks_y_labels(&ticks, &vegetables);
///
///     // add text
///     let mut text = Text::new();
///     text.set_color("white").set_align_horizontal("center");
///     for i in 0..vegetables.len() {
///         for j in 0..farmers.len() {
///             text.draw(j as f64, i as f64, harvest[i][j].to_string().as_str());
///         }
///     }
///     plot.add(&text);
///
///     // save figure
///     plot.save("/tmp/plotpy/doc_tests/doc_plot_2.svg")?;
///     Ok(())
/// }
/// ```
///
/// ![doc_plot_2.svg](https://raw.githubusercontent.com/cpmech/plotpy/main/figures/doc_plot_2.svg)
///
/// See also integration tests in the [tests directory](https://github.com/cpmech/plotpy/tree/main/tests)
pub struct Plot {
    show_errors: bool,              // show python errors, if any
    buffer: String,                 // buffer
    save_tight: bool,               // option for savefig: enable bbox_inches='tight'
    save_pad_inches: Option<f64>,   // option for savefig: add some padding when save_tight==true
    save_transparent: Option<bool>, // option for savefig: make it transparent
    python_exe: String,             // `python3` or simply `python` (e.g., on Windows)
}

impl Plot {
    /// Creates new Plot object
    pub fn new() -> Self {
        Plot {
            show_errors: false,
            buffer: String::new(),
            save_tight: true,
            save_pad_inches: None,
            save_transparent: None,
            python_exe: DEFAULT_PYTHON_EXE.to_string(),
        }
    }

    /// Adds new graph entity
    pub fn add(&mut self, graph: &dyn GraphMaker) -> &mut Self {
        self.buffer.push_str(graph.get_buffer());
        self
    }

    /// Tells matplotlib to try to figure out the tight bounding box of the figure (default = true)
    pub fn set_save_tight(&mut self, tight: bool) -> &mut Self {
        self.save_tight = tight;
        self
    }

    /// Sets the padding around the figure when the 'tight' layout is enabled during saving
    ///
    /// This option may circumvent *rare* problems when matplotlib fails to compute the best bounding box
    /// (e.g., when the labels of 3D plots are ignored)
    pub fn set_save_pad_inches(&mut self, pad_inches: f64) -> &mut Self {
        self.save_pad_inches = Some(pad_inches);
        self
    }

    /// Sets the transparency during saving
    pub fn set_save_transparent(&mut self, transparent: bool) -> &mut Self {
        self.save_transparent = Some(transparent);
        self
    }

    /// Calls Python and saves the python script and figure
    ///
    /// # Input
    ///
    /// * `figure_path` -- may be a String, &str, or Path
    ///
    /// # Notes
    ///
    /// 1. You may want to call [Plot::set_show_errors()] to enable the
    ///    display of Python errors (if any)
    pub fn save<S>(&self, figure_path: &S) -> Result<(), StrError>
    where
        S: AsRef<OsStr> + ?Sized,
    {
        self.run(figure_path, false)
    }

    /// Calls Python, saves the python script and figure, and shows the plot window
    ///
    /// # Input
    ///
    /// * `figure_path` -- may be a String, &str, or Path
    ///
    /// # Notes
    ///
    /// 1. You may want to call [Plot::set_show_errors()] to enable the
    ///    display of Python errors (if any)
    /// 2. This function will also save a figure as [Plot::save()] does
    pub fn show<S>(&self, figure_path: &S) -> Result<(), StrError>
    where
        S: AsRef<OsStr> + ?Sized,
    {
        self.run(figure_path, true)
    }

    /// Calls Python, saves the python script and figure, and shows the result in a Jupyter notebook
    ///
    /// **Important:** This function requires [evcxr_jupyter](https://github.com/evcxr/evcxr).
    ///
    /// # Input
    ///
    /// * `figure_path` -- may be a String, &str or Path
    ///
    /// # Notes
    ///
    /// 1. You may want to call [Plot::set_show_errors()] to enable the
    ///    display of Python errors (if any)
    /// 2. This function will also save a figure as [Plot::save()] does
    /// 3. This method only works in a Jupyter Notebook
    pub fn show_in_jupyter<S>(&self, figure_path: &S) -> Result<(), StrError>
    where
        S: AsRef<OsStr> + ?Sized,
    {
        self.run(figure_path, false)?;
        let fig_path = Path::new(figure_path);
        match fs::read_to_string(fig_path) {
            Ok(figure) => println!("EVCXR_BEGIN_CONTENT text/html\n{}\nEVCXR_END_CONTENT", figure),
            Err(_) => return Err("Failed to read the SVG figure, please check it."),
        }
        Ok(())
    }

    /// Clears the current axes
    pub fn clear_current_axes(&mut self) -> &mut Self {
        self.buffer.push_str("plt.gca().cla()\n");
        self
    }

    /// Clears current figure
    pub fn clear_current_figure(&mut self) -> &mut Self {
        self.buffer.push_str("plt.clf()\n");
        self
    }

    /// Adds legend to plot (see Legend for further options)
    pub fn legend(&mut self) -> &mut Self {
        let mut legend = Legend::new();
        legend.draw();
        self.add(&legend)
    }

    /// Adds grid and labels
    pub fn grid_and_labels(&mut self, xlabel: &str, ylabel: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_axisbelow(True)\n\
             plt.grid(linestyle='--',color='grey',zorder=-1000)\n\
             plt.gca().set_xlabel(r'{}')\n\
             plt.gca().set_ylabel(r'{}')\n",
            xlabel, ylabel
        )
        .unwrap();
        self
    }

    /// Adds grid, labels, and legend
    pub fn grid_labels_legend(&mut self, xlabel: &str, ylabel: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_axisbelow(True)\n\
             plt.grid(linestyle='--',color='grey',zorder=-1000)\n\
             plt.gca().set_xlabel(r'{}')\n\
             plt.gca().set_ylabel(r'{}')\n",
            xlabel, ylabel
        )
        .unwrap();
        self.legend()
    }

    /// Enables the display of python errors (if any)
    pub fn set_show_errors(&mut self, option: bool) -> &mut Self {
        self.show_errors = option;
        self
    }

    /// Configures 3D subplots
    ///
    /// # Input
    ///
    /// * `row` -- number of rows in the subplot_3d grid
    /// * `col` -- number of columns in the subplot_3d grid
    /// * `index` -- activate current 3D subplot; **indices start at one** (1-based)
    pub fn set_subplot_3d(&mut self, row: usize, col: usize, index: usize) -> &mut Self {
        write!(&mut self.buffer, "\nsubplot_3d({},{},{})\n", row, col, index).unwrap();
        self
    }

    /// Configures subplots
    ///
    /// # Input
    ///
    /// * `row` -- number of rows in the subplot grid
    /// * `col` -- number of columns in the subplot grid
    /// * `index` -- activate current subplot; **indices start at one** (1-based)
    pub fn set_subplot(&mut self, row: usize, col: usize, index: usize) -> &mut Self {
        write!(&mut self.buffer, "\nplt.subplot({},{},{})\n", row, col, index).unwrap();
        self
    }

    /// Configures subplots using GridSpec
    ///
    /// # Input
    ///
    /// * `grid_handle` -- an identifier for GridSpec to be used later with [Plot::set_subplot_grid]
    /// * `row` -- number of rows in the grid
    /// * `col` -- number of columns in the grid
    /// * `options` -- (may be empty) Comma separated options. Example `"wspace=0,hspace=0.35"`.
    ///    See <https://matplotlib.org/stable/api/_as_gen/matplotlib.gridspec.GridSpec.html>
    pub fn set_gridspec(&mut self, grid_handle: &str, row: usize, col: usize, options: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "grid_{}=plt.GridSpec({},{},{})\n",
            grid_handle, row, col, options
        )
        .unwrap();
        self
    }

    /// Sets a subplot configured via GridSpec
    ///
    /// See function [Plot::set_gridspec]
    ///
    /// # Input
    ///
    /// * `grid_handle` -- an identifier for GridSpec defined by [Plot::set_gridspec]
    /// * `i_range` -- the **zero-based** row index or range such as "0" or "0:2"
    /// * `j_range` -- the **zero-based** column index or range such as "0" or "0:2"
    pub fn set_subplot_grid(&mut self, grid_handle: &str, i_range: &str, j_range: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "\nplt.subplot(grid_{}[{},{}])\n",
            grid_handle, i_range, j_range
        )
        .unwrap();
        self
    }

    /// Sets the rotation of ticks along the x-axis
    pub fn set_rotation_ticks_x(&mut self, rotation: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().tick_params(axis='x',rotation={})\n",
            rotation
        )
        .unwrap();
        self
    }

    /// Sets the rotation of ticks along the y-axis
    pub fn set_rotation_ticks_y(&mut self, rotation: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().tick_params(axis='y',rotation={})\n",
            rotation
        )
        .unwrap();
        self
    }

    /// Aligns the labels when using subplots
    pub fn set_align_labels(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gcf().align_labels()\n").unwrap();
        self
    }

    /// Adds a title to the plot or sub-plot
    ///
    /// # Notes
    ///
    /// 1. Single quotation marks are replaced by the [UTF-8 Right Single Quotation Mark](https://www.compart.com/en/unicode/U+2019)
    ///    because the Python script already uses the single quotation mark. Note that cannot use the raw notation `"""` because
    ///    otherwise some TeX formula wouldn't work; notably the ones starting with `\v` such as `\varepsilon`
    pub fn set_title(&mut self, title: &str) -> &mut Self {
        let t = title.replace("'", "’");
        write!(&mut self.buffer, "plt.title(r'{}')\n", t).unwrap();
        self
    }

    /// Adds a title to all sub-plots
    ///
    /// # Notes
    ///
    /// 1. Single quotation marks are replaced by the [UTF-8 Right Single Quotation Mark](https://www.compart.com/en/unicode/U+2019)
    ///    because the Python script already uses the single quotation mark. Note that cannot use the raw notation `"""` because
    ///    otherwise some TeX formula wouldn't work; notably the ones starting with `\v` such as `\varepsilon`
    /// 2. The TeX handling in the super-title string is more limited than in the title string
    ///    because we cannot use Python's raw string notation (`r''`) here. The reason is that we want
    ///    the super-title to be wrapped if it is too long and only non-raw strings can do that.
    pub fn set_super_title(&mut self, title: &str, params: Option<&SuperTitleParams>) -> &mut Self {
        let t = title.replace("'", "’").replace("\\n", "'+'\\n'+r'");
        match params {
            Some(p) => write!(&mut self.buffer, "st=plt.suptitle(r'{}'{})\n", t, p.options()).unwrap(),
            None => write!(&mut self.buffer, "st=plt.suptitle(r'{}')\n", t).unwrap(),
        }
        write!(&mut self.buffer, "add_to_ea(st)\n").unwrap();
        self
    }

    /// Sets the horizontal gap between subplots
    pub fn set_horizontal_gap(&mut self, value: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.subplots_adjust(wspace={})\n", value).unwrap();
        self
    }

    /// Sets the vertical gap between subplots
    pub fn set_vertical_gap(&mut self, value: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.subplots_adjust(hspace={})\n", value).unwrap();
        self
    }

    /// Sets the horizontal and vertical gap between subplots
    pub fn set_gaps(&mut self, horizontal: f64, vertical: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.subplots_adjust(wspace={},hspace={})\n",
            horizontal, vertical
        )
        .unwrap();
        self
    }

    /// Sets same scale for both axes
    pub fn set_equal_axes(&mut self, equal: bool) -> &mut Self {
        if equal {
            self.buffer.push_str("set_equal_axes()\n");
        } else {
            self.buffer.push_str("plt.gca().axes.set_aspect('auto')\n");
        }
        self
    }

    /// Sets the figure size in inches
    pub fn set_figure_size_inches(&mut self, width: f64, height: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gcf().set_size_inches({},{})\n", width, height).unwrap();
        self
    }

    /// Sets the figure size in points
    #[rustfmt::skip]
    pub fn set_figure_size_points(&mut self, width: f64, height: f64) -> &mut Self {
        const FACTOR: f64 = 72.27;
        write!(&mut self.buffer, "plt.gcf().set_size_inches({},{})\n", width / FACTOR, height / FACTOR).unwrap();
        self
    }

    /// Sets an option to hide the ticks along the x axis
    pub fn set_hide_xticks(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_xticklabels([])\n").unwrap();
        self
    }

    /// Sets an option to hide the ticks along the y axis
    pub fn set_hide_yticks(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_yticklabels([])\n").unwrap();
        self
    }

    /// Sets an option to hide the ticks along the z axis
    pub fn set_hide_zticks(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_zticklabels([])\n").unwrap();
        self
    }

    /// Sets an option to hide/show all axes
    pub fn set_hide_axes(&mut self, hide: bool) -> &mut Self {
        let option = if hide { "off" } else { "on" };
        write!(&mut self.buffer, "plt.axis('{}')\n", option).unwrap();
        self
    }

    /// Sets an option to hide/show the 3D grid and panes (make them transparent)
    ///
    /// **Important:** This function must be called after adding all 3D surfaces/curves to the plot.
    pub fn set_hide_3d_grid(&mut self, hide: bool) -> &mut Self {
        if hide {
            self.buffer.push_str(
                "plt.gca().xaxis.pane.set_color((1.0, 1.0, 1.0, 0.0))\n\
                 plt.gca().yaxis.pane.set_color((1.0, 1.0, 1.0, 0.0))\n\
                 plt.gca().zaxis.pane.set_color((1.0, 1.0, 1.0, 0.0))\n\
                 plt.gca().grid(False)\n",
            );
        } else {
            self.buffer.push_str("plt.gca().grid(True)\n");
        }
        self
    }

    /// Sets axes limits
    pub fn set_range_3d(&mut self, xmin: f64, xmax: f64, ymin: f64, ymax: f64, zmin: f64, zmax: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_xlim({},{})\n\
             plt.gca().set_ylim({},{})\n\
             plt.gca().set_zlim({},{})\n",
            xmin, xmax, ymin, ymax, zmin, zmax,
        )
        .unwrap();
        self
    }

    /// Sets axes limits
    pub fn set_range(&mut self, xmin: f64, xmax: f64, ymin: f64, ymax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.axis([{},{},{},{}])\n", xmin, xmax, ymin, ymax).unwrap();
        self
    }

    /// Sets axes limits from vector
    pub fn set_range_from_vec(&mut self, limits: &[f64]) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.axis([{},{},{},{}])\n",
            limits[0], limits[1], limits[2], limits[3]
        )
        .unwrap();
        self
    }

    /// Sets minimum x
    pub fn set_xmin(&mut self, xmin: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_xlim([{},None])\n", xmin).unwrap();
        self
    }

    /// Sets maximum x
    pub fn set_xmax(&mut self, xmax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_xlim([None,{}])\n", xmax).unwrap();
        self
    }

    /// Sets minimum y
    pub fn set_ymin(&mut self, ymin: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_ylim([{},None])\n", ymin).unwrap();
        self
    }

    /// Sets maximum y
    pub fn set_ymax(&mut self, ymax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_ylim([None,{}])\n", ymax).unwrap();
        self
    }

    /// Sets minimum z
    pub fn set_zmin(&mut self, zmin: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_zlim([{},None])\n", zmin).unwrap();
        self
    }

    /// Sets maximum z
    pub fn set_zmax(&mut self, zmax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_zlim([None,{}])\n", zmax).unwrap();
        self
    }

    /// Sets x-range (i.e. limits)
    pub fn set_xrange(&mut self, xmin: f64, xmax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_xlim([{},{}])\n", xmin, xmax).unwrap();
        self
    }

    /// Sets y-range (i.e. limits)
    pub fn set_yrange(&mut self, ymin: f64, ymax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_ylim([{},{}])\n", ymin, ymax).unwrap();
        self
    }

    /// Sets z-range (i.e. limits)
    pub fn set_zrange(&mut self, zmin: f64, zmax: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_zlim([{},{}])\n", zmin, zmax).unwrap();
        self
    }

    /// Sets number of ticks along x
    pub fn set_num_ticks_x(&mut self, num: usize) -> &mut Self {
        if num == 0 {
            self.buffer.push_str("plt.gca().get_xaxis().set_ticks([])\n");
        } else {
            write!(
                &mut self.buffer,
                "plt.gca().get_xaxis().set_major_locator(tck.MaxNLocator({}))\n",
                num
            )
            .unwrap();
        }
        self
    }

    /// Sets number of ticks along y
    pub fn set_num_ticks_y(&mut self, num: usize) -> &mut Self {
        if num == 0 {
            self.buffer.push_str("plt.gca().get_yaxis().set_ticks([])\n");
        } else {
            write!(
                &mut self.buffer,
                "plt.gca().get_yaxis().set_major_locator(tck.MaxNLocator({}))\n",
                num
            )
            .unwrap();
        }
        self
    }

    /// Sets number of ticks along z
    pub fn set_num_ticks_z(&mut self, num: usize) -> &mut Self {
        if num == 0 {
            self.buffer.push_str("plt.gca().get_zaxis().set_ticks([])\n");
        } else {
            write!(
                &mut self.buffer,
                "plt.gca().get_zaxis().set_major_locator(tck.MaxNLocator({}))\n",
                num
            )
            .unwrap();
        }
        self
    }

    /// Sets the number and format of x-ticks
    ///
    /// # Input
    ///
    /// * `major_every` -- step for major ticks (ignored if ≤ 0.0)
    /// * `minor_every` -- step for major ticks (ignored if ≤ 0.0)
    /// * `major_number_format` -- C-style number format for major ticks; e.g. "%.2f" (ignored if empty "")
    ///    See [matplotlib FormatStrFormatter](https://matplotlib.org/stable/api/ticker_api.html#matplotlib.ticker.FormatStrFormatter)
    #[rustfmt::skip]
    pub fn set_ticks_x(&mut self, major_every: f64, minor_every: f64, major_number_format: &str) -> &mut Self {
        if major_every > 0.0 {
            write!(&mut self.buffer, "major_locator = tck.MultipleLocator({})\n", major_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / {}\n", major_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < major_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().xaxis.set_major_locator(major_locator)\n").unwrap();
        }
        if minor_every > 0.0 {
            write!(&mut self.buffer, "minor_locator = tck.MultipleLocator({})\n", minor_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / {}\n", minor_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < minor_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().xaxis.set_minor_locator(minor_locator)\n").unwrap();
        }
        if major_number_format != "" {
            write!(&mut self.buffer, "major_formatter = tck.FormatStrFormatter(r'{}')\n", major_number_format).unwrap();
            write!(&mut self.buffer, "plt.gca().xaxis.set_major_formatter(major_formatter)\n").unwrap();
        }
        self
    }

    /// Sets the number and format of y-ticks
    ///
    /// # Input
    ///
    /// * `major_every` -- step for major ticks (ignored if ≤ 0.0)
    /// * `minor_every` -- step for major ticks (ignored if ≤ 0.0)
    /// * `major_number_format` -- C-style number format for major ticks; e.g. "%.2f" (ignored if empty "")
    ///    See [matplotlib FormatStrFormatter](https://matplotlib.org/stable/api/ticker_api.html#matplotlib.ticker.FormatStrFormatter)
    #[rustfmt::skip]
    pub fn set_ticks_y(&mut self, major_every: f64, minor_every: f64, major_number_format: &str) -> &mut Self {
        if major_every > 0.0 {
            write!(&mut self.buffer, "major_locator = tck.MultipleLocator({})\n", major_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / {}\n", major_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < major_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().yaxis.set_major_locator(major_locator)\n").unwrap();
        }
        if minor_every > 0.0 {
            write!(&mut self.buffer, "minor_locator = tck.MultipleLocator({})\n", minor_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / {}\n", minor_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < minor_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().yaxis.set_minor_locator(minor_locator)\n").unwrap();
        }
        if major_number_format != "" {
            write!(&mut self.buffer, "major_formatter = tck.FormatStrFormatter(r'{}')\n", major_number_format).unwrap();
            write!(&mut self.buffer, "plt.gca().yaxis.set_major_formatter(major_formatter)\n").unwrap();
        }
        self
    }

    /// Sets the ticks and labels along x
    pub fn set_ticks_x_labels<'a, S, T, U>(&mut self, ticks: &'a T, labels: &[S]) -> &mut Self
    where
        S: std::fmt::Display,
        T: AsVector<'a, U>,
        U: 'a + std::fmt::Display + Num,
    {
        assert_eq!(ticks.vec_size(), labels.len());
        vector_to_array(&mut self.buffer, "tx", ticks);
        generate_list_quoted(&mut self.buffer, "lx", labels);
        write!(
            &mut self.buffer,
            "plt.gca().set_xticks(tx)\nplt.gca().set_xticklabels(lx)\n"
        )
        .unwrap();
        self
    }

    /// Sets the ticks and labels along y
    pub fn set_ticks_y_labels<'a, S, T, U>(&mut self, ticks: &'a T, labels: &[S]) -> &mut Self
    where
        S: std::fmt::Display,
        T: AsVector<'a, U>,
        U: 'a + std::fmt::Display + Num,
    {
        assert_eq!(ticks.vec_size(), labels.len());
        vector_to_array(&mut self.buffer, "ty", ticks);
        generate_list_quoted(&mut self.buffer, "ly", labels);
        write!(
            &mut self.buffer,
            "plt.gca().set_yticks(ty)\nplt.gca().set_yticklabels(ly)\n"
        )
        .unwrap();
        self
    }

    /// Sets the fontsize of the ticks for the x-axis
    pub fn set_ticks_x_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().tick_params(axis='x',labelsize={})\n",
            fontsize,
        )
        .unwrap();
        self
    }

    /// Sets the fontsize of the ticks for the y-axis
    pub fn set_ticks_y_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().tick_params(axis='y',labelsize={})\n",
            fontsize,
        )
        .unwrap();
        self
    }

    /// Sets the fontsize of the ticks for the z-axis
    pub fn set_ticks_z_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().tick_params(axis='z',labelsize={})\n",
            fontsize,
        )
        .unwrap();
        self
    }

    /// Writes the function multiple_of_pi_formatter to buffer
    #[inline]
    fn write_multiple_of_pi_formatter(&mut self) {
        write!(
            &mut self.buffer,
            "def multiple_of_pi_formatter(x, pos):\n\
             \x20\x20\x20\x20den = 2\n\
             \x20\x20\x20\x20num = int(np.rint(den*x/np.pi))\n\
             \x20\x20\x20\x20com = np.gcd(num,den)\n\
             \x20\x20\x20\x20(num,den) = (int(num/com),int(den/com))\n\
             \x20\x20\x20\x20if den==1:\n\
             \x20\x20\x20\x20\x20\x20\x20\x20if num==0: return r'$0$'\n\
             \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\pi$'\n\
             \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$-\\pi$'\n\
             \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$%s\\pi$'%num\n\
             \x20\x20\x20\x20else:\n\
             \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\frac{{\\pi}}{{%s}}$'%den\n\
             \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$\\frac{{-\\pi}}{{%s}}$'%den\n\
             \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$\\frac{{%s\\pi}}{{%s}}$'%(num,den)\n"
        )
        .unwrap();
    }

    /// Sets the x-ticks to multiples of pi
    ///
    /// # Input
    ///
    /// * `minor_every` -- step for major ticks (ignored if ≤ 0.0). Example `PI / 12.0`
    ///
    /// **Note:** This function sets the major ticks as `PI / 2.0`.
    #[rustfmt::skip]
    pub fn set_ticks_x_multiple_of_pi(&mut self, minor_every: f64) -> &mut Self {
        write!(&mut self.buffer, "major_locator = tck.MultipleLocator(np.pi/2.0)\n").unwrap();
        write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / (np.pi/2.0)\n").unwrap();
        write!(&mut self.buffer, "if n_ticks < major_locator.MAXTICKS * 0.9:\n").unwrap();
        write!(&mut self.buffer, "    plt.gca().xaxis.set_major_locator(major_locator)\n").unwrap();
        if minor_every > 0.0 {
            write!(&mut self.buffer, "minor_locator = tck.MultipleLocator({})\n", minor_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / {}\n", minor_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < minor_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().xaxis.set_minor_locator(minor_locator)\n").unwrap();
        }
        self.write_multiple_of_pi_formatter();
        write!(&mut self.buffer, "major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n").unwrap();
        write!(&mut self.buffer, "plt.gca().xaxis.set_major_formatter(major_formatter)\n").unwrap();
        self
    }

    /// Sets the y-ticks to multiples of pi
    ///
    /// # Input
    ///
    /// * `minor_every` -- step for major ticks (ignored if ≤ 0.0). Example `PI / 12.0`
    ///
    /// **Note:** This function sets the major ticks as `PI / 2.0`.
    #[rustfmt::skip]
    pub fn set_ticks_y_multiple_of_pi(&mut self, minor_every: f64) -> &mut Self {
        write!(&mut self.buffer, "major_locator = tck.MultipleLocator(np.pi/2.0)\n").unwrap();
        write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / (np.pi/2.0)\n").unwrap();
        write!(&mut self.buffer, "if n_ticks < major_locator.MAXTICKS * 0.9:\n").unwrap();
        write!(&mut self.buffer, "    plt.gca().yaxis.set_major_locator(major_locator)\n").unwrap();
        if minor_every > 0.0 {
            write!(&mut self.buffer, "minor_locator = tck.MultipleLocator({})\n", minor_every).unwrap();
            write!(&mut self.buffer, "n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / {}\n", minor_every).unwrap();
            write!(&mut self.buffer, "if n_ticks < minor_locator.MAXTICKS * 0.9:\n").unwrap();
            write!(&mut self.buffer, "    plt.gca().yaxis.set_minor_locator(minor_locator)\n").unwrap();
        }
        self.write_multiple_of_pi_formatter();
        write!(&mut self.buffer, "major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n").unwrap();
        write!(&mut self.buffer, "plt.gca().yaxis.set_major_formatter(major_formatter)\n").unwrap();
        self
    }

    /// Sets a log10 x-scale
    ///
    /// # Note
    ///
    /// `set_log_x(true)` must be called before adding curves.
    pub fn set_log_x(&mut self, log: bool) -> &mut Self {
        if log {
            self.buffer.push_str("plt.gca().set_xscale('log')\n");
        } else {
            self.buffer.push_str("plt.gca().set_xscale('linear')\n");
        }
        self
    }

    /// Sets a log10 y-scale
    ///
    /// # Note
    ///
    /// `set_log_y(true)` must be called before adding curves.
    pub fn set_log_y(&mut self, log: bool) -> &mut Self {
        if log {
            self.buffer.push_str("plt.gca().set_yscale('log')\n");
        } else {
            self.buffer.push_str("plt.gca().set_yscale('linear')\n");
        }
        self
    }

    /// Sets the label for the x-axis
    pub fn set_label_x(&mut self, label: &str) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_xlabel(r'{}')\n", label).unwrap();
        self
    }

    /// Sets the label for the y-axis
    pub fn set_label_y(&mut self, label: &str) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_ylabel(r'{}')\n", label).unwrap();
        self
    }

    /// Sets the label for the z-axis
    pub fn set_label_z(&mut self, label: &str) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().set_zlabel(r'{}')\n", label).unwrap();
        self
    }

    /// Sets the fontsize of the label for the x-axis
    pub fn set_label_x_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().xaxis.label.set_fontsize({})\n", fontsize,).unwrap();
        self
    }

    /// Sets the fontsize of the label for the y-axis
    pub fn set_label_y_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().yaxis.label.set_fontsize({})\n", fontsize,).unwrap();
        self
    }

    /// Sets the fontsize of the label for the z-axis
    pub fn set_label_z_fontsize(&mut self, fontsize: f64) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().zaxis.label.set_fontsize({})\n", fontsize,).unwrap();
        self
    }

    /// Sets the color of the label for the x-axis
    pub fn set_label_x_color(&mut self, color: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().xaxis.label.set_color('{}')\n\
             plt.gca().tick_params(axis='x',labelcolor='{}')\n",
            color, color
        )
        .unwrap();
        self
    }

    /// Sets the color of the label for the y-axis
    pub fn set_label_y_color(&mut self, color: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().yaxis.label.set_color('{}')\n\
             plt.gca().tick_params(axis='y',labelcolor='{}')\n",
            color, color
        )
        .unwrap();
        self
    }

    /// Sets the color of the label for the z-axis
    pub fn set_label_z_color(&mut self, color: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().zaxis.label.set_color('{}')\n\
             plt.gca().tick_params(axis='z',labelcolor='{}')\n",
            color, color
        )
        .unwrap();
        self
    }

    /// Sets the label for the y-axis on a twin-x graph
    ///
    /// **Warning:** The curve with a twin-x graph must be added first
    pub fn set_label_y_twinx(&mut self, label: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "if 'ax_twinx' in locals():\n\
             \x20\x20\x20\x20ax_twinx.set_ylabel(r'{}')\n",
            label,
        )
        .unwrap();
        self
    }

    /// Sets the color of the label for the y-axis on a twin-x graph
    ///
    /// **Warning:** The curve with a twin-x graph must be added first
    pub fn set_label_y_twinx_color(&mut self, color: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "if 'ax_twinx' in locals():\n\
             \x20\x20\x20\x20ax_twinx.yaxis.label.set_color('{}')\n\
             \x20\x20\x20\x20ax_twinx.tick_params(axis='y',labelcolor='{}')\n",
            color, color
        )
        .unwrap();
        self
    }

    /// Sets the label for the x-axis and the padding
    pub fn set_label_x_and_pad(&mut self, label: &str, pad: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_xlabel(r'{}',labelpad={})\n",
            label, pad
        )
        .unwrap();
        self
    }

    /// Sets the label for the y-axis and the padding
    pub fn set_label_y_and_pad(&mut self, label: &str, pad: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_ylabel(r'{}',labelpad={})\n",
            label, pad
        )
        .unwrap();
        self
    }

    /// Sets the label for the z-axis and the padding
    pub fn set_label_z_and_pad(&mut self, label: &str, pad: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_zlabel(r'{}',labelpad={})\n",
            label, pad
        )
        .unwrap();
        self
    }

    /// Sets the labels for the x and y axes
    pub fn set_labels(&mut self, xlabel: &str, ylabel: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_xlabel(r'{}')\nplt.gca().set_ylabel(r'{}')\n",
            xlabel, ylabel
        )
        .unwrap();
        self
    }

    /// Sets the labels for the x, y, and z axes
    pub fn set_labels_3d(&mut self, xlabel: &str, ylabel: &str, zlabel: &str) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().set_xlabel(r'{}')\nplt.gca().set_ylabel(r'{}')\nplt.gca().set_zlabel(r'{}')\n",
            xlabel, ylabel, zlabel
        )
        .unwrap();
        self
    }

    /// Sets inverted x-axis
    pub fn set_inv_x(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().invert_xaxis()\n").unwrap();
        self
    }

    /// Sets inverted y-axis
    pub fn set_inv_y(&mut self) -> &mut Self {
        write!(&mut self.buffer, "plt.gca().invert_yaxis()\n").unwrap();
        self
    }

    /// Sets camera in 3d graph. Sets the elevation and azimuth of the axes.
    ///
    /// # Input
    ///
    /// * `elevation` -- is the elevation angle in the z plane
    /// * `azimuth` -- is the azimuth angle in the x,y plane
    ///
    /// | view plane | elev | azim |
    /// |------------|------|------|
    /// | XY         | 90   | -90  |
    /// | XZ         | 0    | -90  |
    /// | YZ         | 0    | 0    |
    /// | -XY        | -90  | 90   |
    /// | -XZ        | 0    | 90   |
    /// | -YZ        | 0    | 180  |
    ///
    /// See <https://matplotlib.org/stable/api/_as_gen/mpl_toolkits.mplot3d.axes3d.Axes3D.view_init.html>
    pub fn set_camera(&mut self, elevation: f64, azimuth: f64) -> &mut Self {
        write!(
            &mut self.buffer,
            "plt.gca().view_init(elev={},azim={})\n",
            elevation, azimuth
        )
        .unwrap();
        self
    }

    /// Sets option to hide (or show) frame borders
    pub fn set_frame_border(&mut self, left: bool, right: bool, bottom: bool, top: bool) -> &mut Self {
        if left {
            self.buffer.push_str("plt.gca().spines['left'].set_visible(True)\n");
        } else {
            self.buffer.push_str("plt.gca().spines['left'].set_visible(False)\n");
        }
        if right {
            self.buffer.push_str("plt.gca().spines['right'].set_visible(True)\n");
        } else {
            self.buffer.push_str("plt.gca().spines['right'].set_visible(False)\n");
        }
        if bottom {
            self.buffer.push_str("plt.gca().spines['bottom'].set_visible(True)\n");
        } else {
            self.buffer.push_str("plt.gca().spines['bottom'].set_visible(False)\n");
        }
        if top {
            self.buffer.push_str("plt.gca().spines['top'].set_visible(True)\n");
        } else {
            self.buffer.push_str("plt.gca().spines['top'].set_visible(False)\n");
        }
        self
    }

    /// Sets visibility of all frame borders
    pub fn set_frame_borders(&mut self, show_all: bool) -> &mut Self {
        self.set_frame_border(show_all, show_all, show_all, show_all)
    }

    /// Draws an infinite horizontal line at y
    pub fn set_horiz_line(&mut self, y: f64, color: &str, line_style: &str, line_width: f64) -> &mut Self {
        let opt = format!(",color='{}',linestyle='{}',linewidth={}", color, line_style, line_width);
        self.buffer.push_str(&format!("plt.axhline({}{})\n", y, &opt));
        self
    }

    /// Draws an infinite vertical line at x
    pub fn set_vert_line(&mut self, x: f64, color: &str, line_style: &str, line_width: f64) -> &mut Self {
        let opt = format!(",color='{}',linestyle='{}',linewidth={}", color, line_style, line_width);
        self.buffer.push_str(&format!("plt.axvline({}{})\n", x, &opt));
        self
    }

    /// Draws infinite horizontal and vertical lines at (x, y)
    pub fn set_cross(&mut self, x: f64, y: f64, color: &str, line_style: &str, line_width: f64) -> &mut Self {
        let opt = format!(",color='{}',linestyle='{}',linewidth={}", color, line_style, line_width);
        self.buffer
            .push_str(&format!("plt.axhline({}{})\nplt.axvline({}{})\n", y, &opt, x, &opt));
        self
    }

    /// Writes extra python commands
    pub fn extra(&mut self, commands: &str) -> &mut Self {
        self.buffer.write_str(commands).unwrap();
        self
    }

    /// Sets the Python3 executable command
    ///
    /// The default is `python3`
    pub fn set_python_exe(&mut self, python_exe: &str) -> &mut Self {
        self.python_exe = python_exe.to_string();
        self
    }

    /// Run python
    fn run<S>(&self, figure_path: &S, show: bool) -> Result<(), StrError>
    where
        S: AsRef<OsStr> + ?Sized,
    {
        // update commands
        let fig_path = Path::new(figure_path);
        let mut txt = "plt.savefig(fn".to_string();
        if self.save_tight {
            txt.push_str(",bbox_inches='tight',bbox_extra_artists=EXTRA_ARTISTS");
        }
        if let Some(pad) = self.save_pad_inches {
            txt.push_str(format!(",pad_inches={}", pad).as_str());
        }
        if let Some(transparent) = self.save_transparent {
            if transparent {
                txt.push_str(",transparent=True");
            }
        }
        txt.push_str(")\n");
        if show {
            txt.push_str("\nplt.show()\n");
        };
        let commands = format!("{}\nfn=r'{}'\n{}", self.buffer, fig_path.to_string_lossy(), txt);

        // call python
        let mut path = Path::new(figure_path).to_path_buf();
        path.set_extension("py");
        let output = call_python3(&self.python_exe, &commands, &path)?;

        // handle error => write log file
        if output != "" {
            let mut log_path = Path::new(figure_path).to_path_buf();
            log_path.set_extension("log");
            let mut log_file = File::create(log_path).map_err(|_| "cannot create log file")?;
            log_file
                .write_all(output.as_bytes())
                .map_err(|_| "cannot write to log file")?;
            if self.show_errors {
                println!("{}", output);
            }
            return Err("python3 failed; please see the log file");
        }
        Ok(())
    }
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

#[cfg(test)]
mod tests {
    use crate::SuperTitleParams;

    use super::Plot;
    use std::fs::File;
    use std::io::{BufRead, BufReader};
    use std::path::Path;

    const OUT_DIR: &str = "/tmp/plotpy/unit_tests";

    #[test]
    fn new_plot_works() {
        let plot = Plot::new();
        assert_eq!(plot.buffer.len(), 0);
    }

    #[test]
    fn save_works() {
        let plot = Plot::new();
        assert_eq!(plot.buffer.len(), 0);
        let path = Path::new(OUT_DIR).join("save_works.svg");
        plot.save(&path).unwrap();
        let file = File::open(&path).map_err(|_| "cannot open file").unwrap();
        let buffered = BufReader::new(file);
        let lines_iter = buffered.lines();
        assert!(lines_iter.count() > 20);
    }

    #[test]
    fn show_in_jupyter_works() {
        let plot = Plot::new();
        let path = Path::new(OUT_DIR).join("show_works.svg");
        plot.save(&path).unwrap();
        let result = plot.show_in_jupyter(&path).unwrap();
        assert_eq!(result, ());
    }

    #[test]
    fn save_str_works() {
        let plot = Plot::new();
        assert_eq!(plot.buffer.len(), 0);
        let path = "/tmp/plotpy/unit_tests/save_str_works.svg";
        plot.save(&path).unwrap();
        let file = File::open(&path).map_err(|_| "cannot open file").unwrap();
        let buffered = BufReader::new(file);
        let lines_iter = buffered.lines();
        assert!(lines_iter.count() > 20);
    }

    #[test]
    fn show_errors_works() {
        const WRONG: usize = 0;
        let mut plot = Plot::new();
        plot.set_show_errors(true);
        plot.set_subplot(1, 1, WRONG);
        let path = Path::new(OUT_DIR).join("show_errors_works.svg");
        assert_eq!(plot.save(&path).err(), Some("python3 failed; please see the log file"));
    }

    #[test]
    fn subplot_3d_works() {
        let mut plot = Plot::new();
        plot.set_subplot_3d(3, 2, 1);
        let b: &str = "\nsubplot_3d(3,2,1)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn subplot_functions_work() {
        let mut plot = Plot::new();
        plot.set_super_title("all subplots", None)
            .set_subplot(2, 2, 1)
            .set_horizontal_gap(0.1)
            .set_vertical_gap(0.2)
            .set_gaps(0.3, 0.4);
        let b: &str = "st=plt.suptitle(r'all subplots')\n\
                       add_to_ea(st)\n\
                       \nplt.subplot(2,2,1)\n\
                         plt.subplots_adjust(wspace=0.1)\n\
                         plt.subplots_adjust(hspace=0.2)\n\
                         plt.subplots_adjust(wspace=0.3,hspace=0.4)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn super_title_works() {
        let mut params = SuperTitleParams::new();
        params
            .set_x(123.3)
            .set_y(456.7)
            .set_align_horizontal("left")
            .set_align_vertical("bottom")
            .set_fontsize(12.0)
            .set_fontweight(10.0);
        let mut plot = Plot::new();
        plot.set_super_title("all subplots", Some(&params));
        let b: &str =
            "st=plt.suptitle(r'all subplots',x=123.3,y=456.7,ha='left',va='bottom',fontsize=12,fontweight=10)\n\
                       add_to_ea(st)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn grid_functions_work() {
        let mut plot = Plot::new();
        plot.grid_and_labels("xx", "yy").grid_labels_legend("xx", "yy").legend();
        let b: &str = "plt.gca().set_axisbelow(True)\n\
                       plt.grid(linestyle='--',color='grey',zorder=-1000)\n\
                       plt.gca().set_xlabel(r'xx')\n\
                       plt.gca().set_ylabel(r'yy')\n\
                       plt.gca().set_axisbelow(True)\n\
                       plt.grid(linestyle='--',color='grey',zorder=-1000)\n\
                       plt.gca().set_xlabel(r'xx')\n\
                       plt.gca().set_ylabel(r'yy')\n\
                       h,l=plt.gca().get_legend_handles_labels()\n\
                       if len(h)>0 and len(l)>0:\n\
                       \x20\x20\x20\x20leg=plt.legend(handlelength=3,ncol=1,loc='best')\n\
                       \x20\x20\x20\x20add_to_ea(leg)\n\
                       h,l=plt.gca().get_legend_handles_labels()\n\
                       if len(h)>0 and len(l)>0:\n\
                       \x20\x20\x20\x20leg=plt.legend(handlelength=3,ncol=1,loc='best')\n\
                       \x20\x20\x20\x20add_to_ea(leg)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn set_title_and_super_title_handle_quotes() {
        let mut p1 = Plot::new();
        p1.set_title("Without Quotes").set_super_title("Hi", None);
        let b: &str = "plt.title(r'Without Quotes')\n\
                       st=plt.suptitle(r'Hi')\n\
                       add_to_ea(st)\n";
        assert_eq!(p1.buffer, b);

        let mut p2 = Plot::new();
        p2.set_title("Developer's Plot").set_super_title("Dev's", None);
        let b: &str = "plt.title(r'Developer’s Plot')\n\
                       st=plt.suptitle(r'Dev’s')\n\
                       add_to_ea(st)\n";
        assert_eq!(p2.buffer, b);

        let mut p3 = Plot::new();
        p3.set_title("\"Look at This\"").set_super_title("\"Dev's\"", None);
        let b: &str = "plt.title(r'\"Look at This\"')\n\
                       st=plt.suptitle(r'\"Dev’s\"')\n\
                       add_to_ea(st)\n";
        assert_eq!(p3.buffer, b);
    }

    #[test]
    fn set_super_title_handles_math_and_newline() {
        let mut plot = Plot::new();
        plot.set_super_title("$\\alpha$\\n$\\beta$", None);
        let b: &str = "st=plt.suptitle(r'$\\alpha$'+'\\n'+r'$\\beta$')\n\
                       add_to_ea(st)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn set_functions_work() {
        let mut plot = Plot::new();
        plot.set_show_errors(true)
            .set_equal_axes(true)
            .set_equal_axes(false)
            .set_hide_axes(true)
            .set_range_3d(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0)
            .set_range(-1.0, 1.0, -1.0, 1.0)
            .set_range_from_vec(&[0.0, 1.0, 0.0, 1.0])
            .set_xrange(-80.0, 800.0)
            .set_yrange(13.0, 130.0)
            .set_zrange(44.0, 444.0)
            .set_xmin(-3.0)
            .set_xmax(8.0)
            .set_ymin(-7.0)
            .set_ymax(33.0)
            .set_zmin(12.0)
            .set_zmax(34.0)
            .set_num_ticks_x(0)
            .set_num_ticks_x(8)
            .set_num_ticks_y(0)
            .set_num_ticks_y(5)
            .set_log_x(true)
            .set_log_y(true)
            .set_log_x(false)
            .set_log_y(false)
            .set_label_x("x-label")
            .set_label_y("y-label")
            .set_labels("x", "y")
            .set_camera(1.0, 10.0)
            .set_ticks_x(1.5, 0.5, "%.2f")
            .set_ticks_y(0.5, 0.1, "%g")
            .set_figure_size_inches(2.0, 2.0)
            .set_figure_size_points(7227.0, 7227.0)
            .clear_current_axes()
            .clear_current_figure();
        let b: &str = "set_equal_axes()\n\
                       plt.gca().axes.set_aspect('auto')\n\
                       plt.axis('off')\n\
                       plt.gca().set_xlim(-1,1)\n\
                       plt.gca().set_ylim(-1,1)\n\
                       plt.gca().set_zlim(-1,1)\n\
                       plt.axis([-1,1,-1,1])\n\
                       plt.axis([0,1,0,1])\n\
                       plt.gca().set_xlim([-80,800])\n\
                       plt.gca().set_ylim([13,130])\n\
                       plt.gca().set_zlim([44,444])\n\
                       plt.gca().set_xlim([-3,None])\n\
                       plt.gca().set_xlim([None,8])\n\
                       plt.gca().set_ylim([-7,None])\n\
                       plt.gca().set_ylim([None,33])\n\
                       plt.gca().set_zlim([12,None])\n\
                       plt.gca().set_zlim([None,34])\n\
                       plt.gca().get_xaxis().set_ticks([])\n\
                       plt.gca().get_xaxis().set_major_locator(tck.MaxNLocator(8))\n\
                       plt.gca().get_yaxis().set_ticks([])\n\
                       plt.gca().get_yaxis().set_major_locator(tck.MaxNLocator(5))\n\
                       plt.gca().set_xscale('log')\n\
                       plt.gca().set_yscale('log')\n\
                       plt.gca().set_xscale('linear')\n\
                       plt.gca().set_yscale('linear')\n\
                       plt.gca().set_xlabel(r'x-label')\n\
                       plt.gca().set_ylabel(r'y-label')\n\
                       plt.gca().set_xlabel(r'x')\n\
                       plt.gca().set_ylabel(r'y')\n\
                       plt.gca().view_init(elev=1,azim=10)\n\
                       major_locator = tck.MultipleLocator(1.5)\n\
                       n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / 1.5\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().xaxis.set_major_locator(major_locator)\n\
                       minor_locator = tck.MultipleLocator(0.5)\n\
                       n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / 0.5\n\
                       if n_ticks < minor_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().xaxis.set_minor_locator(minor_locator)\n\
                       major_formatter = tck.FormatStrFormatter(r'%.2f')\n\
                       plt.gca().xaxis.set_major_formatter(major_formatter)\n\
                       major_locator = tck.MultipleLocator(0.5)\n\
                       n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / 0.5\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().yaxis.set_major_locator(major_locator)\n\
                       minor_locator = tck.MultipleLocator(0.1)\n\
                       n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / 0.1\n\
                       if n_ticks < minor_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().yaxis.set_minor_locator(minor_locator)\n\
                       major_formatter = tck.FormatStrFormatter(r'%g')\n\
                       plt.gca().yaxis.set_major_formatter(major_formatter)\n\
                       plt.gcf().set_size_inches(2,2)\n\
                       plt.gcf().set_size_inches(100,100)\n\
                       plt.gca().cla()\n\
                       plt.clf()\n";
        assert_eq!(plot.buffer, b);
        assert_eq!(plot.show_errors, true);
    }

    #[test]
    fn set_functions_work_2() {
        let mut plot = Plot::new();
        plot.set_ticks_x_multiple_of_pi(0.0);
        let b: &str = "major_locator = tck.MultipleLocator(np.pi/2.0)\n\
                       n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / (np.pi/2.0)\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().xaxis.set_major_locator(major_locator)\n\
                       def multiple_of_pi_formatter(x, pos):\n\
                       \x20\x20\x20\x20den = 2\n\
                       \x20\x20\x20\x20num = int(np.rint(den*x/np.pi))\n\
                       \x20\x20\x20\x20com = np.gcd(num,den)\n\
                       \x20\x20\x20\x20(num,den) = (int(num/com),int(den/com))\n\
                       \x20\x20\x20\x20if den==1:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==0: return r'$0$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$-\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$%s\\pi$'%num\n\
                       \x20\x20\x20\x20else:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\frac{\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$\\frac{-\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$\\frac{%s\\pi}{%s}$'%(num,den)\n\
                       major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n\
                       plt.gca().xaxis.set_major_formatter(major_formatter)\n";
        assert_eq!(plot.buffer, b);

        let mut plot = Plot::new();
        plot.set_ticks_y_multiple_of_pi(0.0);
        let b: &str = "major_locator = tck.MultipleLocator(np.pi/2.0)\n\
                       n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / (np.pi/2.0)\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().yaxis.set_major_locator(major_locator)\n\
                       def multiple_of_pi_formatter(x, pos):\n\
                       \x20\x20\x20\x20den = 2\n\
                       \x20\x20\x20\x20num = int(np.rint(den*x/np.pi))\n\
                       \x20\x20\x20\x20com = np.gcd(num,den)\n\
                       \x20\x20\x20\x20(num,den) = (int(num/com),int(den/com))\n\
                       \x20\x20\x20\x20if den==1:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==0: return r'$0$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$-\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$%s\\pi$'%num\n\
                       \x20\x20\x20\x20else:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\frac{\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$\\frac{-\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$\\frac{%s\\pi}{%s}$'%(num,den)\n\
                       major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n\
                       plt.gca().yaxis.set_major_formatter(major_formatter)\n";
        assert_eq!(plot.buffer, b);

        let mut plot = Plot::new();
        plot.set_ticks_x_multiple_of_pi(1.0);
        let b: &str = "major_locator = tck.MultipleLocator(np.pi/2.0)\n\
                       n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / (np.pi/2.0)\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().xaxis.set_major_locator(major_locator)\n\
                       minor_locator = tck.MultipleLocator(1)\n\
                       n_ticks = (plt.gca().axis()[1] - plt.gca().axis()[0]) / 1\n\
                       if n_ticks < minor_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().xaxis.set_minor_locator(minor_locator)\n\
                       def multiple_of_pi_formatter(x, pos):\n\
                       \x20\x20\x20\x20den = 2\n\
                       \x20\x20\x20\x20num = int(np.rint(den*x/np.pi))\n\
                       \x20\x20\x20\x20com = np.gcd(num,den)\n\
                       \x20\x20\x20\x20(num,den) = (int(num/com),int(den/com))\n\
                       \x20\x20\x20\x20if den==1:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==0: return r'$0$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$-\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$%s\\pi$'%num\n\
                       \x20\x20\x20\x20else:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\frac{\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$\\frac{-\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$\\frac{%s\\pi}{%s}$'%(num,den)\n\
                       major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n\
                       plt.gca().xaxis.set_major_formatter(major_formatter)\n";
        assert_eq!(plot.buffer, b);

        let mut plot = Plot::new();
        plot.set_ticks_y_multiple_of_pi(1.0);
        let b: &str = "major_locator = tck.MultipleLocator(np.pi/2.0)\n\
                       n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / (np.pi/2.0)\n\
                       if n_ticks < major_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().yaxis.set_major_locator(major_locator)\n\
                       minor_locator = tck.MultipleLocator(1)\n\
                       n_ticks = (plt.gca().axis()[3] - plt.gca().axis()[2]) / 1\n\
                       if n_ticks < minor_locator.MAXTICKS * 0.9:\n\
                       \x20\x20\x20\x20plt.gca().yaxis.set_minor_locator(minor_locator)\n\
                       def multiple_of_pi_formatter(x, pos):\n\
                       \x20\x20\x20\x20den = 2\n\
                       \x20\x20\x20\x20num = int(np.rint(den*x/np.pi))\n\
                       \x20\x20\x20\x20com = np.gcd(num,den)\n\
                       \x20\x20\x20\x20(num,den) = (int(num/com),int(den/com))\n\
                       \x20\x20\x20\x20if den==1:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==0: return r'$0$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$-\\pi$'\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$%s\\pi$'%num\n\
                       \x20\x20\x20\x20else:\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20if num==1: return r'$\\frac{\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20elif num==-1: return r'$\\frac{-\\pi}{%s}$'%den\n\
                       \x20\x20\x20\x20\x20\x20\x20\x20else: return r'$\\frac{%s\\pi}{%s}$'%(num,den)\n\
                       major_formatter = tck.FuncFormatter(multiple_of_pi_formatter)\n\
                       plt.gca().yaxis.set_major_formatter(major_formatter)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn set_frame_functions_work() {
        let mut plot = Plot::new();
        plot.set_frame_border(false, false, false, false)
            .set_frame_border(true, true, true, true)
            .set_frame_borders(false);
        let b: &str = "plt.gca().spines['left'].set_visible(False)\n\
                       plt.gca().spines['right'].set_visible(False)\n\
                       plt.gca().spines['bottom'].set_visible(False)\n\
                       plt.gca().spines['top'].set_visible(False)\n\
                       plt.gca().spines['left'].set_visible(True)\n\
                       plt.gca().spines['right'].set_visible(True)\n\
                       plt.gca().spines['bottom'].set_visible(True)\n\
                       plt.gca().spines['top'].set_visible(True)\n\
                       plt.gca().spines['left'].set_visible(False)\n\
                       plt.gca().spines['right'].set_visible(False)\n\
                       plt.gca().spines['bottom'].set_visible(False)\n\
                       plt.gca().spines['top'].set_visible(False)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn additional_features_work() {
        let mut plot = Plot::new();
        plot.set_inv_x()
            .set_inv_y()
            .set_hide_xticks()
            .set_hide_yticks()
            .set_hide_zticks()
            .set_label_x_and_pad("X IS CLOSER NOW", -15.0)
            .set_label_y_and_pad("Y IS CLOSER NOW", -25.0)
            .set_label_z_and_pad("Z IS CLOSER NOW", -35.0)
            .extra("plt.show()\n");
        let b: &str = "plt.gca().invert_xaxis()\n\
                       plt.gca().invert_yaxis()\n\
                       plt.gca().set_xticklabels([])\n\
                       plt.gca().set_yticklabels([])\n\
                       plt.gca().set_zticklabels([])\n\
                       plt.gca().set_xlabel(r'X IS CLOSER NOW',labelpad=-15)\n\
                       plt.gca().set_ylabel(r'Y IS CLOSER NOW',labelpad=-25)\n\
                       plt.gca().set_zlabel(r'Z IS CLOSER NOW',labelpad=-35)\n\
                       plt.show()\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn gridspec_functions_work() {
        let mut plot = Plot::new();
        plot.set_gridspec("the_grid", 2, 2, "wspace=0.1,hspace=0.2")
            .set_subplot_grid("the_grid", "0:2", "0")
            .set_rotation_ticks_x(55.0)
            .set_rotation_ticks_y(45.0)
            .set_align_labels();
        let b: &str = "grid_the_grid=plt.GridSpec(2,2,wspace=0.1,hspace=0.2)\n\
                       \nplt.subplot(grid_the_grid[0:2,0])\n\
                       plt.gca().tick_params(axis='x',rotation=55)\n\
                       plt.gca().tick_params(axis='y',rotation=45)\n\
                       plt.gcf().align_labels()\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn set_labels_3d_works() {
        let mut plot = Plot::new();
        plot.set_label_z("Z").set_labels_3d("X", "Y", "Z");
        let b: &str = "plt.gca().set_zlabel(r'Z')\n\
                       plt.gca().set_xlabel(r'X')\n\
                       plt.gca().set_ylabel(r'Y')\n\
                       plt.gca().set_zlabel(r'Z')\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn extra_functionality_works() {
        let mut plot = Plot::new();
        plot.set_horiz_line(-1.0, "blue", "-", 1.1)
            .set_vert_line(-2.0, "green", ":", 1.2)
            .set_cross(0.25, 0.75, "red", "--", 3.0);
        let b: &str = "plt.axhline(-1,color='blue',linestyle='-',linewidth=1.1)\n\
                       plt.axvline(-2,color='green',linestyle=':',linewidth=1.2)\n\
                       plt.axhline(0.75,color='red',linestyle='--',linewidth=3)\n\
                       plt.axvline(0.25,color='red',linestyle='--',linewidth=3)\n";
        assert_eq!(plot.buffer, b);
    }

    #[test]
    fn set_python_exe_works() {
        let mut plot = Plot::new();
        assert_eq!(plot.python_exe, "python3");
        plot.set_python_exe("python");
        assert_eq!(plot.python_exe, "python");
    }
}