如何在 php 中进行 3*3 矩阵乘法？

Question

How can i do 3*3 or 3*1 matrix multiplication in php with following code.我如何使用以下代码在 php 中进行 3*3 或 3*1 矩阵乘法。 where should i have to change the logic ?????我应该在哪里改变逻辑？？？？

this code completely work for only 2*2 matrix multiplication此代码仅适用于 2*2 矩阵乘法

Here is my code:这是我的代码：

$a = Array( Array(1,2),Array(4,5));
$b = Array( Array(7,5), Array(3,2));

$sumArray = array();

$c = array();

for($i=0;$i<2;$i++)
{
    for($j=0;$j<2;$j++)
    {
        $c[$i][$j]=0;
        for($k=0;$k<2;$k++)
        {

            $c[$i][$j]=$c[$i][$j]+($a[$i][$k]*$b[$k][$j]);
        }
    }
}


echo "<pre/>";
print_r($c);
?>

Answer 1

Matrix Multiplication Rules :矩阵乘法规则：

First matrix's column and Second matrix's row must be same第一个矩阵的列和第二个矩阵的行必须相同

Result matrix's size will be First matrix's Row and Second matrix's Column结果矩阵的大小将是第一个矩阵的行和第二个矩阵的列

$a = Array( Array(1,2),Array(4,5));
$b = Array( Array(7,5), Array(3,2));

$r=count($a);
$c=count($b[0]);
$p=count($b);
if(count($a[0]) != $p){
    echo "Incompatible matrices";
    exit(0);
}
$result=array();
for ($i=0; $i < $r; $i++){
    for($j=0; $j < $c; $j++){
        $result[$i][$j] = 0;
        for($k=0; $k < $p; $k++){
            $result[$i][$j] += $a[$i][$k] * $b[$k][$j];
        }
    }
}
print_r($result);

Answer 2

Matrix computation is achieved by multiplying any column or row elements by their own cofactors.矩阵计算是通过将任何列或行元素乘以它们自己的辅助因子来实现的。

Codes according to your request;根据您的要求编码；

<?php
if ($_POST['hsp']) {
$de3t11=$_POST['m11']; $de3t12=$_POST['m12'];  $de3t13=$_POST['m13']; 
$de3t21=$_POST['m21'];  $de3t22=$_POST['m22'];  $de3t23=$_POST['m14']; 
$de3t31=$_POST['m31'];  $de3t32=$_POST['m23'];  $de3t33=$_POST['m15']; 

//show on screen
 echo $de3t11 ." ". $de3t12. " ". $de3t13;
 echo "<br>";
 echo $de3t21 ." ". $de3t22. " ". $de3t23;
 echo "<br>";
 echo $de3t31 ." ". $de3t32. " ". $de3t33;
 echo "<br>";

//calculate matrix
$m3m11=(($de3t22*$de3t33)-($de3t23*$de3t32))*(1);
$m3m12=(($de3t21*$de3t33)-($de3t23*$de3t31))*(-1);
$m3m13=(($de3t21*$de3t32)-($de3t22*$de3t31))*(1);

//Determinant
$det3t3=(($de3t11*$m3m11)+($de3t12*$m3m12)+($de3t13*$m3m13));

echo $det3t3;


}



 ?>


<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>

<form action="" method="POST">
    <input type="number" name="m11">
    <input type="number" name="m12">
    <input type="number" name="m13">
    <br><br>
    <input type="number" name="m21">
    <input type="number" name="m22">
    <input type="number" name="m23">
    <br><br>
    <input type="number" name="m31">
    <input type="number" name="m32">
    <input type="number" name="m33">


    <input type="submit" name="hsp">
</form>


</body>
</html>

如何在 php 中进行 3*3 矩阵乘法？

问题描述

2 个解决方案

解决方案1
2 2016-12-08 07:27:51

解决方案2
0 2020-06-22 10:56:15

如何在 php 中进行 3*3 矩阵乘法？

问题描述

2 个解决方案

解决方案1 2 2016-12-08 07:27:51

解决方案2 0 2020-06-22 10:56:15

解决方案1
2 2016-12-08 07:27:51

解决方案2
0 2020-06-22 10:56:15