YUI.add('matrix', function (Y, NAME) {

/**

 * Matrix utilities.

 *

 * @class MatrixUtil

 * @module matrix

 **/

var MatrixUtil = {

        /**

         * Used as value for the _rounding method.

         *

         * @property _rounder

         * @private

         */

        _rounder: 100000,

        /**

         * Rounds values

         *

         * @method _round

         * @private

         */

        _round: function(val) {

            val = Math.round(val * MatrixUtil._rounder) / MatrixUtil._rounder;

            return val;

        },

        /**

         * Converts a radian value to a degree.

         *

         * @method rad2deg

         * @param {Number} rad Radian value to be converted.

         * @return Number

         */

        rad2deg: function(rad) {

            var deg = rad * (180 / Math.PI);

            return deg;

        },

        /**

         * Converts a degree value to a radian.

         *

         * @method deg2rad

         * @param {Number} deg Degree value to be converted to radian.

         * @return Number

         */

        deg2rad: function(deg) {

            var rad = deg * (Math.PI / 180);

            return rad;

        },

        /**

         * Converts an angle to a radian

         *

         * @method angle2rad

         * @param {Objecxt} val Value to be converted to radian.

         * @return Number

         */

        angle2rad: function(val) {

            if (typeof val === 'string' && val.indexOf('rad') > -1) {

                val = parseFloat(val);

            } else { // default to deg

                val = MatrixUtil.deg2rad(parseFloat(val));

            }

            return val;

        },

        /**

         * Converts a transform object to an array of column vectors.

         *

         * /                                             \

         * | matrix[0][0]   matrix[1][0]    matrix[2][0] |

         * | matrix[0][1]   matrix[1][1]    matrix[2][1] |

         * | matrix[0][2]   matrix[1][2]    matrix[2][2] |

         * \                                             /

         *

         * @method getnxn

         * @return Array

         */

        convertTransformToArray: function(matrix)

        {

            var matrixArray = [

                    [matrix.a, matrix.c, matrix.dx],

                    [matrix.b, matrix.d, matrix.dy],

                    [0, 0, 1]

                ];

            return matrixArray;

        },

        /**

         * Returns the determinant of a given matrix.

         *

         * /                                             \

         * | matrix[0][0]   matrix[1][0]    matrix[2][0] |

         * | matrix[0][1]   matrix[1][1]    matrix[2][1] |

         * | matrix[0][2]   matrix[1][2]    matrix[2][2] |

         * | matrix[0][3]   matrix[1][3]    matrix[2][3] |

         * \                                             /

         *

         * @method getDeterminant

         * @param {Array} matrix An nxn matrix represented an array of vector (column) arrays. Each vector array has index for each row.

         * @return Number

         */

        getDeterminant: function(matrix)

        {

            var determinant = 0,

                len = matrix.length,

                i = 0,

                multiplier;

            if(len == 2)

            {

                return matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0];

            }

            for(; i < len; ++i)

            {

                multiplier = matrix[i][0];

                if(i % 2 === 0 || i === 0)

                {

                    determinant += multiplier * MatrixUtil.getDeterminant(MatrixUtil.getMinors(matrix, i, 0));

                }

                else

                {

                    determinant -= multiplier * MatrixUtil.getDeterminant(MatrixUtil.getMinors(matrix, i, 0));

                }

            }

            return determinant;

        },

        /**

         * Returns the inverse of a matrix

         *

         * @method inverse

         * @param Array matrix An array representing an nxn matrix

         * @return Array

         *

         * /                                             \

         * | matrix[0][0]   matrix[1][0]    matrix[2][0] |

         * | matrix[0][1]   matrix[1][1]    matrix[2][1] |

         * | matrix[0][2]   matrix[1][2]    matrix[2][2] |

         * | matrix[0][3]   matrix[1][3]    matrix[2][3] |

         * \                                             /

         */

        inverse: function(matrix)

        {

            var determinant = 0,

                len = matrix.length,

                i = 0,

                j,

                inverse,

                adjunct = [],

                //vector representing 2x2 matrix

                minor = [];

            if(len === 2)

            {

                determinant = matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0];

                inverse = [

                    [matrix[1][1] * determinant, -matrix[1][0] * determinant],

                    [-matrix[0][1] * determinant, matrix[0][0] * determinant]

                ];

            }

            else

            {

                determinant = MatrixUtil.getDeterminant(matrix);

                for(; i < len; ++i)

                {

                    adjunct[i] = [];

                    for(j = 0; j < len; ++j)

                    {

                        minor = MatrixUtil.getMinors(matrix, j, i);

                        adjunct[i][j] = MatrixUtil.getDeterminant(minor);

                        if((i + j) % 2 !== 0 && (i + j) !== 0)

                        {

                            adjunct[i][j] *= -1;

                        }

                    }

                }

                inverse = MatrixUtil.scalarMultiply(adjunct, 1/determinant);

            }

            return inverse;

        },

        /**

         * Multiplies a matrix by a numeric value.

         *

         * @method scalarMultiply

         * @param {Array} matrix The matrix to be altered.

         * @param {Number} multiplier The number to multiply against the matrix.

         * @return Array

         */

        scalarMultiply: function(matrix, multiplier)

        {

            var i = 0,

                j,

                len = matrix.length;

            for(; i < len; ++i)

            {

                for(j = 0; j < len; ++j)

                {

                    matrix[i][j] = MatrixUtil._round(matrix[i][j] * multiplier);

                }

            }

            return matrix;

        },

        /**

         * Returns the transpose for an nxn matrix.

         *

         * @method transpose

         * @param matrix An nxn matrix represented by an array of vector arrays.

         * @return Array

         */

        transpose: function(matrix)

        {

            var len = matrix.length,

                i = 0,

                j = 0,

                transpose = [];

            for(; i < len; ++i)

            {

                transpose[i] = [];

                for(j = 0; j < len; ++j)

                {

                    transpose[i].push(matrix[j][i]);

                }

            }

            return transpose;

        },

        /**

         * Returns a matrix of minors based on a matrix, column index and row index.

         *

         * @method getMinors

         * @param {Array} matrix The matrix from which to extract the matrix of minors.

         * @param {Number} columnIndex A zero-based index representing the specified column to exclude.

         * @param {Number} rowIndex A zero-based index represeenting the specified row to exclude.

         * @return Array

         */

        getMinors: function(matrix, columnIndex, rowIndex)

        {

            var minors = [],

                len = matrix.length,

                i = 0,

                j,

                column;

            for(; i < len; ++i)

            {

                if(i !== columnIndex)

                {

                    column = [];

                    for(j = 0; j < len; ++j)

                    {

                        if(j !== rowIndex)

                        {

                            column.push(matrix[i][j]);

                        }

                    }

                    minors.push(column);

                }

            }

            return minors;

        },

        /**

         * Returns the sign of value

         *

         * @method sign

         * @param {Number} val value to be interpreted

         * @return Number

         */

        sign: function(val)

        {

            return val === 0 ? 1 : val/Math.abs(val);

        },

        /**

         * Multiplies a vector and a matrix

         *

         * @method vectorMatrixProduct

         * @param {Array} vector Array representing a column vector

         * @param {Array} matrix Array representing an nxn matrix

         * @return Array

         */

        vectorMatrixProduct: function(vector, matrix)

        {

            var i,

                j,

                len = vector.length,

                product = [],

                rowProduct;

            for(i = 0; i < len; ++i)

            {

                rowProduct = 0;

                for(j = 0; j < len; ++j)

                {

                    rowProduct += vector[i] * matrix[i][j];

                }

                product[i] = rowProduct;

            }

            return product;

        },

        /**

         * Breaks up a 2d transform matrix into a series of transform operations.

         *

         * @method decompose

         * @param {Array} matrix A 3x3 multidimensional array

         * @return Array

         */

        decompose: function(matrix)

        {

            var a = parseFloat(matrix[0][0]),

                b = parseFloat(matrix[1][0]),

                c = parseFloat(matrix[0][1]),

                d = parseFloat(matrix[1][1]),

                dx = parseFloat(matrix[0][2]),

                dy = parseFloat(matrix[1][2]),

                rotate,

                sx,

                sy,

                shear;

            if((a * d - b * c) === 0)

            {

                return false;

            }

            //get length of vector(ab)

            sx = MatrixUtil._round(Math.sqrt(a * a + b * b));

            //normalize components of vector(ab)

            a /= sx;

            b /= sx;

            shear = MatrixUtil._round(a * c + b * d);

            c -= a * shear;

            d -= b * shear;

            //get length of vector(cd)

            sy = MatrixUtil._round(Math.sqrt(c * c + d * d));

            //normalize components of vector(cd)

            c /= sy;

            d /= sy;

            shear /=sy;

            shear = MatrixUtil._round(MatrixUtil.rad2deg(Math.atan(shear)));

            rotate = MatrixUtil._round(MatrixUtil.rad2deg(Math.atan2(matrix[1][0], matrix[0][0])));

            return [

                ["translate", dx, dy],

                ["rotate", rotate],

                ["skewX", shear],

                ["scale", sx, sy]

            ];

        },

        /**

         * Parses a transform string and returns an array of transform arrays.

         *

         * @method getTransformArray

         * @param {String} val A transform string

         * @return Array

         */

        getTransformArray: function(transform) {

            var re = /\s*([a-z]*)\(([\w,\.,\-,\s]*)\)/gi,

                transforms = [],

                args,

                m,

                decomp,

                methods = MatrixUtil.transformMethods;

            while ((m = re.exec(transform))) {

                if (methods.hasOwnProperty(m[1]))

                {

                    args = m[2].split(',');

                    args.unshift(m[1]);

                    transforms.push(args);

                }

                else if(m[1] == "matrix")

                {

                    args = m[2].split(',');

                    decomp = MatrixUtil.decompose([

                        [args[0], args[2], args[4]],

                        [args[1], args[3], args[5]],

                        [0, 0, 1]

                    ]);

                    transforms.push(decomp[0]);

                    transforms.push(decomp[1]);

                    transforms.push(decomp[2]);

                    transforms.push(decomp[3]);

                }

            }

            return transforms;