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use crate::{
core::prelude::*,
errors::prelude::*,
extensions::prelude::*,
validators::prelude::*,
};
use crate::prelude::Numeric;
/// `ArrayTrait` - Array Split functions
pub trait ArraySplit<T: ArrayElement> where Self: Sized + Clone {
/// Split an array into multiple sub-arrays
///
/// # Arguments
///
/// * `parts` - indices defining how to split the array
/// * `axis` - the axis along which to split. optional, defaults to 0
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 7);
/// let split = arr.array_split(3, None).unwrap();
/// assert_eq!(vec![array_flat!(i32, 0, 1, 2).unwrap(), array_flat!(i32, 3, 4, 5).unwrap(), array_flat!(i32, 6, 7).unwrap()], split);
///
/// let arr = array_arange!(i32, 0, 8);
/// let split = arr.array_split(4, None).unwrap();
/// assert_eq!(vec![array_flat!(i32, 0, 1, 2).unwrap(), array_flat!(i32, 3, 4).unwrap(), array_flat!(i32, 5, 6).unwrap(), array_flat!(i32, 7, 8).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn array_split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Array<T>>, ArrayError>;
/// Split an array into multiple sub-arrays of equal size
///
/// # Arguments
///
/// * `parts` - indices defining how to split the array
/// * `axis` - the axis along which to split. optional, defaults to 0
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 8);
/// let split = arr.split(3, None).unwrap();
/// assert_eq!(vec![array_flat!(i32, 0, 1, 2).unwrap(), array_flat!(i32, 3, 4, 5).unwrap(), array_flat!(i32, 6, 7, 8).unwrap()], split);
///
/// let arr = array_arange!(i32, 0, 7);
/// let split = arr.split(4, None).unwrap();
/// assert_eq!(vec![array_flat!(i32, 0, 1).unwrap(), array_flat!(i32, 2, 3).unwrap(), array_flat!(i32, 4, 5).unwrap(), array_flat!(i32, 6, 7).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Array<T>>, ArrayError>;
/// Split an array into multiple sub-arrays of equal size by axis
///
/// # Arguments
///
/// * `axis` - the axis along which to split
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 3).reshape(&[2, 2]);
/// let split = arr.split_axis(0).unwrap();
/// assert_eq!(vec![array!(i32, [[0, 1]]).unwrap(), array!(i32, [[2, 3]]).unwrap()], split);
///
/// let arr = array_arange!(i32, 0, 7).reshape(&[2, 2, 2]);
/// let split = arr.split_axis(1).unwrap();
/// assert_eq!(vec![array!(i32, [[[0, 1]], [[4, 5]]]).unwrap(), array!(i32, [[[2, 3]], [[6, 7]]]).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn split_axis(&self, axis: usize) -> Result<Vec<Array<T>>, ArrayError>;
/// Split an array into multiple sub-arrays horizontally (column-wise)
///
/// # Arguments
///
/// * `parts` - indices defining how to split the array
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 7).reshape(&[2, 2, 2]).unwrap();
/// let split = arr.hsplit(2).unwrap();
/// assert_eq!(vec![array!(i32, [[[0, 1]], [[4, 5]]]).unwrap(), array!(i32, [[[2, 3]], [[6, 7]]]).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn hsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError>;
/// Split an array into multiple sub-arrays vertically (row-wise)
///
/// # Arguments
///
/// * `parts` - indices defining how to split the array
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 7).reshape(&[2, 2, 2]).unwrap();
/// let split = arr.vsplit(2).unwrap();
/// assert_eq!(vec![array!(i32, [[[0, 1], [2, 3]]]).unwrap(), array!(i32, [[[4, 5], [6, 7]]]).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn vsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError>;
/// Split an array into multiple sub-arrays along the 3rd axis (depth)
///
/// # Arguments
///
/// * `parts` - indices defining how to split the array
///
/// # Examples
/// ```
/// use arr_rs::prelude::*;
///
/// let arr = array_arange!(i32, 0, 7).reshape(&[2, 2, 2]).unwrap();
/// let split = arr.dsplit(2).unwrap();
/// assert_eq!(vec![array!(i32, [[[0], [2]], [[4], [6]]]).unwrap(), array!(i32, [[[1], [3]], [[5], [7]]]).unwrap()], split);
/// ```
///
/// # Errors
///
/// may returns `ArrayError`
fn dsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError>;
}
impl <T: ArrayElement> ArraySplit<T> for Array<T> {
fn array_split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Self>, ArrayError> {
if parts == 0 { return Err(ArrayError::ParameterError { param: "parts", message: "number of sections must be larger than 0", }) }
self.axis_opt_in_bounds(axis)?;
if self.is_empty()? { return Ok(vec![self.clone()]) }
let axis = axis.unwrap_or(0);
let n_total = self.len()?;
let (sections, extras) = (n_total / parts, n_total % parts);
let section_sizes = std::iter::repeat(sections + 1)
.take(extras)
.chain(std::iter::repeat(sections).take(parts - extras))
.collect::<Vec<usize>>()
.insert_at(0, 0);
let mut div_points = vec![0; section_sizes.len()];
(0..div_points.len()).for_each(|i| {
div_points[i] = section_sizes.clone()[0 ..= i]
.iter_mut()
.fold(0, |acc, x| { *x += acc; *x });
});
let arr = self.rollaxis(axis.to_isize(), None);
arr.clone().map_or_else(|_| Err(arr.err().unwrap()), |arr| {
let result = div_points
.windows(2)
.map(|w| arr.clone().into_iter()
.skip(w[0]).take(w[1] - w[0])
.collect::<Self>())
.map(|m| {
if self.ndim()? == 1 { Ok(m) }
else {
let mut new_shape = self.get_shape()?;
new_shape[axis] /= parts;
m.reshape(&new_shape)
}
})
.collect::<Vec<Result<Self, _>>>();
if let Err(err) = result.has_error() { Err(err) }
else { Ok(result.into_iter().map(Result::unwrap).collect()) }
})
}
fn split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Self>, ArrayError> {
self.axis_opt_in_bounds(axis)?;
if parts == 0 {
Err(ArrayError::ParameterError { param: "parts", message: "number of sections must be larger than 0", })
} else {
if self.is_empty()? { return Ok(vec![self.clone()]) }
let n_total = self.shape[axis.unwrap_or(0)];
if n_total % parts == 0 {
self.array_split(parts, axis)
} else {
Err(ArrayError::ParameterError { param: "parts", message: "array split does not result in an equal division", })
}
}
}
fn split_axis(&self, axis: usize) -> Result<Vec<Self>, ArrayError> {
self.axis_in_bounds(axis)?;
if self.is_empty()? || self.ndim()? == 1 { Ok(vec![self.clone()]) }
else { self.array_split(self.shape[axis], Some(axis)) }
}
fn hsplit(&self, parts: usize) -> Result<Vec<Self>, ArrayError> {
self.is_dim_unsupported(&[0])?;
if parts == 0 {
Err(ArrayError::ParameterError { param: "parts", message: "number of sections must be larger than 0", })
} else {
match self.ndim()? {
1 => self.split(parts, Some(0)),
_ => self.split(parts, Some(1)),
}
}
}
fn vsplit(&self, parts: usize) -> Result<Vec<Self>, ArrayError> {
self.is_dim_unsupported(&[0, 1])?;
if parts == 0 {
Err(ArrayError::ParameterError { param: "parts", message: "number of sections must be larger than 0", })
} else {
self.split(parts, Some(0))
}
}
fn dsplit(&self, parts: usize) -> Result<Vec<Self>, ArrayError> {
self.is_dim_unsupported(&[0, 1, 2])?;
if parts == 0 {
Err(ArrayError::ParameterError { param: "parts", message: "number of sections must be larger than 0", })
} else {
self.split(parts, Some(2))
}
}
}
impl <T: ArrayElement> ArraySplit<T> for Result<Array<T>, ArrayError> {
fn array_split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.array_split(parts, axis)
}
fn split(&self, parts: usize, axis: Option<usize>) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.split(parts, axis)
}
fn split_axis(&self, axis: usize) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.split_axis(axis)
}
fn hsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.hsplit(parts)
}
fn vsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.vsplit(parts)
}
fn dsplit(&self, parts: usize) -> Result<Vec<Array<T>>, ArrayError> {
self.clone()?.dsplit(parts)
}
}