<?php

$matrix[1][1]=4.54; $matrix[2][1]="apples"; $matrix[3][1]="coles"; 
$matrix[1][2]=7.2140230; $matrix[2][2]="apples"; $matrix[3][2]="safeway"; 
$matrix[1][3]=15.56; $matrix[2][3]="oranges"; $matrix[3][3]="coles"; 
$matrix[1][4]=2.34; $matrix[2][4]="bananas"; $matrix[3][4]="safeway"; 
$matrix[1][5]=27.98; $matrix[2][5]="grapes"; $matrix[3][5]="coles"; 
$matrix[1][6]=17.68493403; $matrix[2][6]="oranges"; $matrix[3][6]="safeway";

array_multisort(
    $matrix[1], SORT_ASC, SORT_NUMERIC,
    $matrix[2], SORT_ASC, SORT_STRING,
    $matrix[3], SORT_ASC, SORT_STRING
);

var_dump($matrix);

?>