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/*
Copyright (c) 2004-2006, The Dojo Foundation
All Rights Reserved.
Licensed under the Academic Free License version 2.1 or above OR the
modified BSD license. For more information on Dojo licensing, see:
http://dojotoolkit.org/community/licensing.shtml
*/
dojo.provide("dojo.math.matrix");
dojo.math.matrix.iDF = 0;
dojo.math.matrix.ALMOST_ZERO = 1e-10;
dojo.math.matrix.multiply = function (a, b) {
var ay = a.length;
var ax = a[0].length;
var by = b.length;
var bx = b[0].length;
if (ax != by) {
dojo.debug("Can't multiply matricies of sizes " + ax + "," + ay + " and " + bx + "," + by);
return [[0]];
}
var c = [];
for (var k = 0; k < ay; k++) {
c[k] = [];
for (var i = 0; i < bx; i++) {
c[k][i] = 0;
for (var m = 0; m < ax; m++) {
c[k][i] += a[k][m] * b[m][i];
}
}
}
return c;
};
dojo.math.matrix.product = function () {
if (arguments.length == 0) {
dojo.debug("can't multiply 0 matrices!");
return 1;
}
var result = arguments[0];
for (var i = 1; i < arguments.length; i++) {
result = dojo.math.matrix.multiply(result, arguments[i]);
}
return result;
};
dojo.math.matrix.sum = function () {
if (arguments.length == 0) {
dojo.debug("can't sum 0 matrices!");
return 0;
}
var result = dojo.math.matrix.copy(arguments[0]);
var rows = result.length;
if (rows == 0) {
dojo.debug("can't deal with matrices of 0 rows!");
return 0;
}
var cols = result[0].length;
if (cols == 0) {
dojo.debug("can't deal with matrices of 0 cols!");
return 0;
}
for (var i = 1; i < arguments.length; ++i) {
var arg = arguments[i];
if (arg.length != rows || arg[0].length != cols) {
dojo.debug("can't add matrices of different dimensions: first dimensions were " + rows + "x" + cols + ", current dimensions are " + arg.length + "x" + arg[0].length);
return 0;
}
for (var r = 0; r < rows; r++) {
for (var c = 0; c < cols; c++) {
result[r][c] += arg[r][c];
}
}
}
return result;
};
dojo.math.matrix.inverse = function (a) {
if (a.length == 1 && a[0].length == 1) {
return [[1 / a[0][0]]];
}
var tms = a.length;
var m = dojo.math.matrix.create(tms, tms);
var mm = dojo.math.matrix.adjoint(a);
var det = dojo.math.matrix.determinant(a);
var dd = 0;
if (det == 0) {
dojo.debug("Determinant Equals 0, Not Invertible.");
return [[0]];
} else {
dd = 1 / det;
}
for (var i = 0; i < tms; i++) {
for (var j = 0; j < tms; j++) {
m[i][j] = dd * mm[i][j];
}
}
return m;
};
dojo.math.matrix.determinant = function (a) {
if (a.length != a[0].length) {
dojo.debug("Can't calculate the determiant of a non-squre matrix!");
return 0;
}
var tms = a.length;
var det = 1;
var b = dojo.math.matrix.upperTriangle(a);
for (var i = 0; i < tms; i++) {
var bii = b[i][i];
if (Math.abs(bii) < dojo.math.matrix.ALMOST_ZERO) {
return 0;
}
det *= bii;
}
det = det * dojo.math.matrix.iDF;
return det;
};
dojo.math.matrix.upperTriangle = function (m) {
m = dojo.math.matrix.copy(m);
var f1 = 0;
var temp = 0;
var tms = m.length;
var v = 1;
dojo.math.matrix.iDF = 1;
for (var col = 0; col < tms - 1; col++) {
if (typeof m[col][col] != "number") {
dojo.debug("non-numeric entry found in a numeric matrix: m[" + col + "][" + col + "]=" + m[col][col]);
}
v = 1;
var stop_loop = 0;
while ((m[col][col] == 0) && !stop_loop) {
if (col + v >= tms) {
dojo.math.matrix.iDF = 0;
stop_loop = 1;
} else {
for (var r = 0; r < tms; r++) {
temp = m[col][r];
m[col][r] = m[col + v][r];
m[col + v][r] = temp;
}
v++;
dojo.math.matrix.iDF *= -1;
}
}
for (var row = col + 1; row < tms; row++) {
if (typeof m[row][col] != "number") {
dojo.debug("non-numeric entry found in a numeric matrix: m[" + row + "][" + col + "]=" + m[row][col]);
}
if (typeof m[col][row] != "number") {
dojo.debug("non-numeric entry found in a numeric matrix: m[" + col + "][" + row + "]=" + m[col][row]);
}
if (m[col][col] != 0) {
var f1 = (-1) * m[row][col] / m[col][col];
for (var i = col; i < tms; i++) {
m[row][i] = f1 * m[col][i] + m[row][i];
}
}
}
}
return m;
};
dojo.math.matrix.create = function (a, b, value) {
if (!value) {
value = 0;
}
var m = [];
for (var i = 0; i < b; i++) {
m[i] = [];
for (var j = 0; j < a; j++) {
m[i][j] = value;
}
}
return m;
};
dojo.math.matrix.ones = function (a, b) {
return dojo.math.matrix.create(a, b, 1);
};
dojo.math.matrix.zeros = function (a, b) {
return dojo.math.matrix.create(a, b, 0);
};
dojo.math.matrix.identity = function (size, scale) {
if (!scale) {
scale = 1;
}
var m = [];
for (var i = 0; i < size; i++) {
m[i] = [];
for (var j = 0; j < size; j++) {
m[i][j] = (i == j ? scale : 0);
}
}
return m;
};
dojo.math.matrix.adjoint = function (a) {
var tms = a.length;
if (tms <= 1) {
dojo.debug("Can't find the adjoint of a matrix with a dimension less than 2");
return [[0]];
}
if (a.length != a[0].length) {
dojo.debug("Can't find the adjoint of a non-square matrix");
return [[0]];
}
var m = dojo.math.matrix.create(tms, tms);
var ii = 0;
var jj = 0;
var ia = 0;
var ja = 0;
var det = 0;
var ap = dojo.math.matrix.create(tms - 1, tms - 1);
for (var i = 0; i < tms; i++) {
for (var j = 0; j < tms; j++) {
ia = 0;
for (ii = 0; ii < tms; ii++) {
if (ii == i) {
continue;
}
ja = 0;
for (jj = 0; jj < tms; jj++) {
if (jj == j) {
continue;
}
ap[ia][ja] = a[ii][jj];
ja++;
}
ia++;
}
det = dojo.math.matrix.determinant(ap);
m[i][j] = Math.pow(-1, (i + j)) * det;
}
}
m = dojo.math.matrix.transpose(m);
return m;
};
dojo.math.matrix.transpose = function (a) {
var m = dojo.math.matrix.create(a.length, a[0].length);
for (var i = 0; i < a.length; i++) {
for (var j = 0; j < a[i].length; j++) {
m[j][i] = a[i][j];
}
}
return m;
};
dojo.math.matrix.format = function (a, decimal_points) {
if (arguments.length <= 1) {
decimal_points = 5;
}
function format_int(x, dp) {
var fac = Math.pow(10, dp);
var a = Math.round(x * fac) / fac;
var b = a.toString();
if (b.charAt(0) != "-") {
b = " " + b;
}
var has_dp = 0;
for (var i = 1; i < b.length; i++) {
if (b.charAt(i) == ".") {
has_dp = 1;
}
}
if (!has_dp) {
b += ".";
}
while (b.length < dp + 3) {
b += "0";
}
return b;
}
var ya = a.length;
var xa = ya > 0 ? a[0].length : 0;
var buffer = "";
for (var y = 0; y < ya; y++) {
buffer += "| ";
for (var x = 0; x < xa; x++) {
buffer += format_int(a[y][x], decimal_points) + " ";
}
buffer += "|\n";
}
return buffer;
};
dojo.math.matrix.copy = function (a) {
var ya = a.length;
var xa = a[0].length;
var m = dojo.math.matrix.create(xa, ya);
for (var y = 0; y < ya; y++) {
for (var x = 0; x < xa; x++) {
m[y][x] = a[y][x];
}
}
return m;
};
dojo.math.matrix.scale = function (k, a) {
a = dojo.math.matrix.copy(a);
var ya = a.length;
var xa = a[0].length;
for (var y = 0; y < ya; y++) {
for (var x = 0; x < xa; x++) {
a[y][x] *= k;
}
}
return a;
};