function Mat3(elements){
    /**
     * A vector of length 9, containing all matrix elements
     * @property {Array} elements
     */
    if(elements){
        this.elements = elements;
    } else {
        this.elements = [0,0,0,0,0,0,0,0,0];
    }
}
A 3x3 matrix.
@class Mat3
@constructor
@param array elements Array of nine elements. Optional.
@author schteppe / http://github.com/schteppe