Module easy_ml::matrices::iterators

Iterators over parts of a Matrix

Examples

Extending a matrix with new columns

use easy_ml::matrices::Matrix;

// we start with some matrix where the first and second columns correspond
// to x and y points
let mut matrix = Matrix::from(vec![
    vec![ 3.0, 4.0 ],
    vec![ 8.0, 1.0 ],
    vec![ 2.0, 9.0 ]]);
// insert a third column based on the formula x * y
matrix.insert_column_with(2, matrix.column_iter(0)
    // join together the x and y columns
    .zip(matrix.column_iter(1))
    // compute the values for the new column
    .map(|(x, y)| x * y)
    // Collect into a vector so we stop immutably borrowing from `matrix`.
    // This is only neccessary when we use the data from a Matrix to modify itself,
    // because the rust compiler enforces that we do not mutably and immutably borrow
    // something at the same time. If we used data from a different Matrix to update
    // `matrix` then we could stop at map and pass the iterator directly.
    .collect::<Vec<f64>>()
    // now that the Vec created owns the data for the new column and we have stopped
    // borrowing immutably from `matrix` we turn the vec back into an iterator and
    // mutably borrow `matrix` to add the new column
    .drain(..));
assert_eq!(matrix.get(0, 2), 3.0 * 4.0);
assert_eq!(matrix.get(1, 2), 8.0 * 1.0);
assert_eq!(matrix.get(2, 2), 2.0 * 9.0);

Structs

ColumnIterator	An iterator over a column in a matrix.
ColumnMajorIterator	An column major iterator over all values in a matrix.
ColumnMajorReferenceIterator	An column major iterator over references to all values in a matrix.
ColumnReferenceIterator	An iterator over references to a column in a matrix.
RowIterator	An iterator over a row in a matrix.
RowReferenceIterator	An iterator over references to a row in a matrix.