how to compute eigenvector

[cussel]

hy all, how to compute eigenvector from array bellow?
I am confused in make nested loop and temporary for compute eigenvector

please help me!!!

$data = array(
            array(1,-0.52836,0),
            array(-0.52836,1,-0.19845), 
            array(0,-0.19845,1)
            );
$data2 = array(
array(1),
array(1),
array(1)
);

echo "<pre>";
//print_r($data2);
echo "</pre>";



for ($i=0;$i<count($data);$i++)
        {
            for ($j=0;$j<count($data[$i]);$j++)
             {
                 $R2[$i][$j] = (($data[$i][0]*$data[0][$j])+($data[$i][1]*$data[1][$j])+($data[$i][2]*$data[2][$j]));
             }
        }


echo "<pre>";
print_r($R2);
echo "</pre>";



$aR = array();
for ($i=0;$i<count($R2);$i++)
        {
            for ($j=0;$j<count($R2[$i]);$j++)
             {
             if (isset($data2[$i][$j])){
             $aR[]  = (($R2[$i][0]*$data2[$i][$j])+($R2[$i][1]*$data2[$i][$j])+($R2[$i][2]*$data2[$i][$j]));
             }
    }
}
echo "<pre>";
//print_r($aR);
echo "</pre>";

$max = $aR;
$max = (max($max)); 

for ($i=0;$i<count($aR);$i++)
        {
  $iteration[] = round($max/$aR[$i],5);
}       

echo "<pre>";
//print_r($iteration);
echo "</pre>";

[diafol]

is this homework?

[DavidB]

I haven't gone through your code in detail, but perhaps you could give a rough outline of what the inputs are and what the program does.

The reason I ask is because usually when eigenvectors are computed, they are computed for corresponding eigenvalues.

i.e. - Solve [A] - [I]lambda = 0

where lambda is a specific eigenvalue.

Then the process is repeated for each eigenvalue.

I don't see where an eigenvalue is input so that the corresponding eigenvector can be computed. Does the data in the array already represent [A] - [I]lambda? Otherwise, it looks like you are going straight to the computation of the eigenvectors.

[cussel]

this my thesis use PCA method in one of step there is compute eigenvector
can you help me?