Struct Column

Source

pub struct Column { /* private fields */ }

Expand description

One named column of a Table.

A column pairs the values of one source column with the name that the source gives it. The name is fixed when the column is built.

§Examples

use dataset_ml::table::{Column, ColumnData};
use ndarray::array;

let column = Column::new("petal_width", ColumnData::Numeric(array![0.2, 1.4]));

assert_eq!(column.name(), "petal_width");
assert_eq!(column.len(), 2);
assert_eq!(column.as_numeric().unwrap()[0], 0.2);

// An `as_*` method returns `None` for every other variant.
assert!(column.as_string().is_none());

Implementations§

Source §

impl Column

Source

pub fn new(name: &'static str, data: ColumnData) -> Self

Build a column from its name and its values.

§Parameters

name - The name the source gives the column.
data - The values in the column.

§Returns

Self - the new column.

Source

pub fn name(&self) -> &'static str

The column’s name.

§Returns

&'static str - the name, as the source spells it.

Source

pub fn data(&self) -> &ColumnData

The column’s values.

§Returns

&ColumnData - a shared reference to the values.

Source

pub fn data_mut(&mut self) -> &mut ColumnData

The column’s values, for in-place editing.

§Returns

&mut ColumnData - a mutable reference to the values.

§Notes

Change a value, but do not change the number of samples. A Table that holds this column relies on every column having the same length.

Source

pub fn len(&self) -> usize

The number of samples the column holds.

§Returns

usize - the sample count.

Source

pub fn is_empty(&self) -> bool

Whether the column holds no sample.

§Returns

bool - true if the column holds no sample, and false if it holds at least one.

Source

pub fn as_numeric(&self) -> Option<&Array1<f64>>

The values, if the column is ColumnData::Numeric.

§Returns

Some(&Array1<f64>) - the values, one per sample.
None - if the column holds another variant.

Source

pub fn as_integer(&self) -> Option<&Array1<i64>>

The values, if the column is ColumnData::Integer.

§Returns

Some(&Array1<i64>) - the values, one per sample.
None - if the column holds another variant.

Source

pub fn as_string(&self) -> Option<&Array1<String>>

The values, if the column is ColumnData::String.

§Returns

Some(&Array1<String>) - the values, one per sample.
None - if the column holds another variant.

Source

pub fn as_bytes(&self) -> Option<&Array2<u8>>

The values, if the column is ColumnData::Bytes.

§Returns

Some(&Array2<u8>) - the rows, one per sample.
None - if the column holds another variant.

Source

pub fn to_numeric(&self) -> Option<Array1<f64>>

The values as f64, one per sample.

§Returns

Some(Array1<f64>) - the values. ColumnData::Numeric returns them unchanged, and ColumnData::Integer converts each one.
None - if the column is ColumnData::String, which has no numeric reading, or ColumnData::Bytes, which holds more than one value per sample. For a Bytes column, use Table::numeric_matrix.