the php file does not show any output-CodePudding

I used HTML and PH PHP to calculate the normal unit

<html>
<head>
<title> Comprehensive FORM CGI program </title>
</head>
<body bgcolor=#DDDDDD>
<p>
<!-- The lines above are the standard html header -->

<?php

  // First get the input variables and their values

$A = $_POST['f_A'];

$B = $_POST['f_B'];


$Acomponent = explode(",", $A);
$Bcomponent = explode(",", $B);

$AX = (int)$Acomponent[0];
$AY = (int)$Acomponent[1];
$AZ = (int)$Acomponent[2];
$BX = (int)$Bcomponent[0];
$BY = (int)$Bcomponent[1];
$BZ = (int)$Bcomponent[2];


function dot_product($AX, $AY, $AZ, $BX, $BY, $BZ){
$dotproduct = ($AX*$BX $AY*$BY $AZ*$BZ);
return($dotproduct);

}

function cross_product($AX, $AY, $AZ, $BX, $BY, $BZ){
        
        $i = ($AY*$BZ-$AZ*$BY);
        $j = (-1)*($AX*$BZ-$AZ*$BX);
        $k = ($AX*$BY-$AY*$BX);
        return($i);
        return($j);
        return($k);

}


function norm($AX, $AY, $AZ, $BX, $BY, $BZ) {
     
        
        
        $Anorm=sqrt(pow($AX,2) pow($AY,2)  pow($AZ,2));
        $Bnorm=sqrt(pow($BX,2) pow($BY,2)  pow($BZ,2));
        
        return($Anorm);
        return($Bnorm);

}

function anglebetween($dotproduct,$Anorm, $Bnorm) {
        $angle = acos($dotproduct/($Anorm*$Bnorm));
        return($angle);
}

function normalunitvector($i,$j,$k) {
   
        $crossnorm=sqrt(pow($i,2) pow($j,2)  pow($k,2));
        $normaluniti = $i/$crossnorm;
        $normalunitj = $j/$crossnorm;
        $normalunitk = $k/$crossnorm;
        $normalunit = [];
        $normalunit[0] = $normaluniti;
        $normalunit[1] = $normalunitj;
        $normalunit[2] = $normalunitk;
        return($normalunit);
}


dot_product($AX, $AY, $AZ, $BX, $BY, $BZ);
cross_product($AX, $AY, $AZ, $BX, $BY, $BZ);
norm($AX, $AY, $AZ, $BX, $BY, $BZ);
anglebetween($dotproduct,$Anorm, $Bnorm);
normalunitvector($i,$j,$k);

echo($angle);
echo($normaluniti);
echo($normalunitj);
echo($normalunitk);
?>
<p>
<hr>
<p>
</body>
</html>

AX, AY, AZ, BX, BY, BZ values were printed very well, but the value of angle, normaluniti, normalunij, normalunitk were not printed.

I don't know why, but I guess there is an error in my function?

echo($angle);
echo($normaluniti);
echo($normalunitj);
echo($normalunitk);

did not show anything. How can fix this issue?

CodePudding user response：

You're using them as local variables inside your functions. Their life begins and ends between the brackets of a function.

Try echo anglebetween($dotproduct,$Anorm, $Bnorm); tell me if that works.

If so, you can either store anglebetween($dotproduct,$Anorm, $Bnorm); in a variable or just call the functions.

CodePudding user response：

After execution of the functions , please assign the returned value(s) to local variable(s)
For return of multiple values from a single function, please use an array

Hence, please find below a working example :

(For testing, I have added two lines to assign the values of $A and $B, please remove them if you want to apply the values of $_POST)

<html>
<head>
<title> Comprehensive FORM CGI program </title>
</head>
<body bgcolor=#DDDDDD>
<p>
<!-- The lines above are the standard html header -->

<?php

  // First get the input variables and their values

//$A = $_POST['f_A'];
//$B = $_POST['f_B'];

$A = "10,20,30";
$B = "25,100,1000";



$Acomponent = explode(",", $A);
$Bcomponent = explode(",", $B);

$AX = (int)$Acomponent[0];
$AY = (int)$Acomponent[1];
$AZ = (int)$Acomponent[2];
$BX = (int)$Bcomponent[0];
$BY = (int)$Bcomponent[1];
$BZ = (int)$Bcomponent[2];


function dot_product($AX, $AY, $AZ, $BX, $BY, $BZ){
//$dotproduct = ($AX*$BX $AY*$BY $AZ*$BZ);
//return($dotproduct);
return ($AX*$BX $AY*$BY $AZ*$BZ);

}

function cross_product($AX, $AY, $AZ, $BX, $BY, $BZ){
        
        $i = ($AY*$BZ-$AZ*$BY);
        $j = (-1)*($AX*$BZ-$AZ*$BX);
        $k = ($AX*$BY-$AY*$BX);
//        return($i);
//        return($j);
//        return($k);

return array($i, $j, $k);
}


function norm($AX, $AY, $AZ, $BX, $BY, $BZ) {
     
        
        
        $Anorm=sqrt(pow($AX,2) pow($AY,2)  pow($AZ,2));
        $Bnorm=sqrt(pow($BX,2) pow($BY,2)  pow($BZ,2));
        
//        return($Anorm);
//       return($Bnorm);
return array($Anorm,$Bnorm);

}

function anglebetween($dotproduct,$Anorm, $Bnorm) {
//        $angle = acos($dotproduct/($Anorm*$Bnorm));
//        return($angle);
return acos($dotproduct/($Anorm*$Bnorm));

}

function normalunitvector($i,$j,$k) {
   
        $crossnorm=sqrt(pow($i,2) pow($j,2)  pow($k,2));
        $normaluniti = $i/$crossnorm;
        $normalunitj = $j/$crossnorm;
        $normalunitk = $k/$crossnorm;
      //  $normalunit = [];
      //  $normalunit[0] = $normaluniti;
      //  $normalunit[1] = $normalunitj;
      //  $normalunit[2] = $normalunitk;
      //  return($normalunit);
return array($normaluniti, $normalunitj, $normalunitk);
}




$dotproduct=dot_product($AX, $AY, $AZ, $BX, $BY, $BZ);

$array1 = cross_product($AX, $AY, $AZ, $BX, $BY, $BZ);


$i=$array1[0];
$j=$array1[1];
$k=$array1[2];


$array2=norm($AX, $AY, $AZ, $BX, $BY, $BZ);

$Anorm=$array2[0];
$Bnorm=$array2[1];


$angle=anglebetween($dotproduct,$Anorm, $Bnorm);


$array3 =normalunitvector($i,$j,$k);

$normaluniti=$array3[0];
$normalunitj=$array3[1];
$normalunitk=$array3[2];



echo " Angle is :". ($angle);
echo "<br>";

echo " Normaluniti is :".($normaluniti);
echo "<br>";

echo " Normalunitj is :".($normalunitj);
echo "<br>";

echo " Normalunitk is :".($normalunitk);
echo "<br>";



?>
<p>
<hr>
<p>
</body>
</html>