class:
/**
* A collection of 2D matrix functions for AS3.
**/
public dynamic class Matrix2D extends Array
{
public function Matrix2D(nRows:int=0,nCols:int=0)
{
for (var k:int=0;k<nRows;k++)
{
this[k]=new Array(nCols);
}
}
/**
* Returns a square [n][n] matrix with all the elements set to
zero.
*
* @param n Matrix length.
*
* @see #Identity()
**/
public dynamic function Zero(n:int=0):Matrix2D
{
var a:Matrix2D=new Matrix2D(n,n);
for (var i:int=0;i<n;i++)
{
for (var j:int=0;j<n;j++)
{
a[i][j]=0.;
}
}
return (a);
}
/**
* Returns an identity matrix [n][n] with the diagonal elements
set to one.
*
* @param n Matrix length.
*
* @see #Zero()
**/
public dynamic function Identity(n:int=0):Matrix2D
{
var a:Matrix2D=new Matrix2D(n,n);
for (var i:int=0;i<n;i++)
{
for (var j:int=0;j<n;j++)
{
if (i==j)
{
a[i][j]=1.;
}
else
{
a[i][j]=0.;
}
}
}
return (a);
}
}
test:
import com.freevryheid.statistics.Matrix2D;
private function init():void
{
var b:Matrix2D=new Matrix2D();
trace(b.Identity(3))
}
outputs: 1,0,0,0,1,0,0,0,1
