Struct DataFrame 

pub struct DataFrame { /* private fields */ }

Internal columnar DataFrame for data storage and manipulation.

Implementations

impl DataFrame

pub fn new() -> Self

Create an empty DataFrame.

pub fn column(&self, name: &str) -> Option<&[Value]>

Get a column by name.

pub fn nrows(&self) -> usize

Get number of rows.

pub fn ncols(&self) -> usize

Get number of columns.

pub fn column_names(&self) -> Vec<&str>

Get column names.

pub fn has_column(&self, name: &str) -> bool

Check if a column exists.

pub fn add_column(&mut self, name: String, values: Vec<Value>)

Add (or replace) a column.

Never panics. If the length doesn’t match the existing rows, the shorter side is padded with Value::Na and the mismatch is recorded as an issue: building or rendering a plot from this frame then fails with GGError::ValidationError. Use try_add_column to reject the column instead.

pub fn try_add_column( &mut self, name: String, values: Vec<Value>, ) -> Result<(), GGError>

Add (or replace) a column, rejecting a length mismatch with a GGError::ValidationError (the frame is left unchanged).

pub fn issues(&self) -> &[String]

Problems recorded while assembling this frame (empty when well-formed).

pub fn validate(&self) -> Result<(), GGError>

Ok when the frame is well-formed, else a GGError::ValidationError describing every recorded issue.

pub fn column_mut(&mut self, name: &str) -> Option<&mut Vec<Value>>

Get a mutable reference to a column.

pub fn group_by(&self, keys: &[&str]) -> Vec<DataFrame>

Group by one or more key columns. Returns a Vec of DataFrames, one per group.

pub fn vstack(&mut self, other: &DataFrame)

Vertically stack another DataFrame onto this one.

pub fn select(&self, columns: &[&str]) -> DataFrame

Select a subset of columns.

pub fn row(&self, idx: usize) -> IndexMap<String, Value>

Get a single row as a map.

pub fn sort_by(&self, column: &str) -> DataFrame

Sort by a column (ascending). Returns a new DataFrame.

pub fn from_rows(rows: Vec<IndexMap<String, Value>>) -> Self

Create from rows (list of maps).

pub fn unique_values(&self, column: &str) -> Vec<Value>

Get all unique values in a column.

impl DataFrame

pub fn from_csv(path: &str) -> Result<Self, Error>

Load a DataFrame from a CSV file. First row is treated as column headers. Values are parsed as Float if possible, otherwise kept as strings. The literal string “NA” is parsed as Value::Na.

Trait Implementations

impl Clone for DataFrame

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DataFrame

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DataFrame

fn default() -> Self

Returns the “default value” for a type.

impl GGData for DataFrame

Identity: DataFrame passes through.

fn into_dataframe(self) -> DataFrame