<?php

namespace Arma\Internal;

/**
 * Interface for a dense matrix.
 *
 * @package Arma
 */
interface DenseMatrix extends Dense, Matrix
{
    // Subview

    /**
     * {@inheritdoc}
     *
     * @param int $i
     * @param int $j[optional]
     * @return \Arma\MapVal
     */
    function at($i, $j);

    /**
     * {@inheritdoc}
     *
     * @param int $col_number
     * @return \Arma\SvCol
     */
    function col($col_number);

    /**
     * {@inheritdoc}
     *
     * @param int $row_number
     * @return \Arma\SvRow
     */
    function row($row_number);

    /**
     * {@inheritdoc}
     *
     * @param int $first_col
     * @param int $last_col
     * @return \Arma\SvMat
     */
    function cols($first_col, $last_col);

    /**
     * {@inheritdoc}
     *
     * @param int $first_row
     * @param int $last_row
     * @return \Arma\SvMat
     */
    function rows($first_row, $last_row);

    /**
     * {@inheritdoc}
     *
     * @param int $first_row
     * @param int $first_col
     * @param int $last_row
     * @param int $last_col
     * @return \Arma\SvMat
     */
    function submat($first_row, $first_col, $last_row, $last_col);

    /**
     * {@inheritdoc}
     *
     * @param int $n_cols
     * @return \Arma\SvMat
     */
    function head_cols($n_cols);

    /**
     * {@inheritdoc}
     *
     * @param int $n_rows
     * @return \Arma\SvMat
     */
    function head_rows($n_rows);

    /**
     * {@inheritdoc}
     *
     * @param int $n_cols
     * @return \Arma\SvMat
     */
    function tail_cols($n_cols);

    /**
     * {@inheritdoc}
     *
     * @param int $n_rows
     * @return \Arma\SvMat
     */
    function tail_rows($n_rows);

    /**
     * {@inheritdoc}
     *
     * @param int $k[optional]
     * @return \Arma\DiagView
     */
    function diag($k = 0);

    // Iteration

    /**
     * Apply a callback function to each row of the matrix.
     *
     * @param callable $action (\Arma\SvRow) -> void
     * @return void
     */
    function eachRow($action);

    /**
     * Apply a callback function to each column of the matrix.
     *
     * @param callable $action (\Arma\SvCol) -> void
     * @return void
     */
    function eachCol($action);

    // Transform

    /**
     * Returns an inverse of the matrix.
     *
     * @return DenseMatrix
     */
    function i();
}