UNPKG

ml-matrix

Version:

Matrix manipulation and computation library

784 lines (688 loc) 21.4 kB
'use strict'; const Matrix = require('../matrix'); const util = require('./util'); const hypotenuse = util.hypotenuse; const getFilled2DArray = util.getFilled2DArray; const defaultOptions = { assumeSymmetric: false }; // https://github.com/lutzroeder/Mapack/blob/master/Source/EigenvalueDecomposition.cs function EigenvalueDecomposition(matrix, options) { options = Object.assign({}, defaultOptions, options); if (!(this instanceof EigenvalueDecomposition)) { return new EigenvalueDecomposition(matrix, options); } matrix = Matrix.checkMatrix(matrix); if (!matrix.isSquare()) { throw new Error('Matrix is not a square matrix'); } var n = matrix.columns, V = getFilled2DArray(n, n, 0), d = new Array(n), e = new Array(n), value = matrix, i, j; var isSymmetric = false; if (options.assumeSymmetric) { isSymmetric = true; } else { isSymmetric = matrix.isSymmetric(); } if (isSymmetric) { for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { V[i][j] = value.get(i, j); } } tred2(n, e, d, V); tql2(n, e, d, V); } else { var H = getFilled2DArray(n, n, 0), ort = new Array(n); for (j = 0; j < n; j++) { for (i = 0; i < n; i++) { H[i][j] = value.get(i, j); } } orthes(n, H, ort, V); hqr2(n, e, d, V, H); } this.n = n; this.e = e; this.d = d; this.V = V; } EigenvalueDecomposition.prototype = { get realEigenvalues() { return this.d; }, get imaginaryEigenvalues() { return this.e; }, get eigenvectorMatrix() { if (!Matrix.isMatrix(this.V)) { this.V = new Matrix(this.V); } return this.V; }, get diagonalMatrix() { var n = this.n, e = this.e, d = this.d, X = new Matrix(n, n), i, j; for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { X[i][j] = 0; } X[i][i] = d[i]; if (e[i] > 0) { X[i][i + 1] = e[i]; } else if (e[i] < 0) { X[i][i - 1] = e[i]; } } return X; } }; function tred2(n, e, d, V) { var f, g, h, i, j, k, hh, scale; for (j = 0; j < n; j++) { d[j] = V[n - 1][j]; } for (i = n - 1; i > 0; i--) { scale = 0; h = 0; for (k = 0; k < i; k++) { scale = scale + Math.abs(d[k]); } if (scale === 0) { e[i] = d[i - 1]; for (j = 0; j < i; j++) { d[j] = V[i - 1][j]; V[i][j] = 0; V[j][i] = 0; } } else { for (k = 0; k < i; k++) { d[k] /= scale; h += d[k] * d[k]; } f = d[i - 1]; g = Math.sqrt(h); if (f > 0) { g = -g; } e[i] = scale * g; h = h - f * g; d[i - 1] = f - g; for (j = 0; j < i; j++) { e[j] = 0; } for (j = 0; j < i; j++) { f = d[j]; V[j][i] = f; g = e[j] + V[j][j] * f; for (k = j + 1; k <= i - 1; k++) { g += V[k][j] * d[k]; e[k] += V[k][j] * f; } e[j] = g; } f = 0; for (j = 0; j < i; j++) { e[j] /= h; f += e[j] * d[j]; } hh = f / (h + h); for (j = 0; j < i; j++) { e[j] -= hh * d[j]; } for (j = 0; j < i; j++) { f = d[j]; g = e[j]; for (k = j; k <= i - 1; k++) { V[k][j] -= (f * e[k] + g * d[k]); } d[j] = V[i - 1][j]; V[i][j] = 0; } } d[i] = h; } for (i = 0; i < n - 1; i++) { V[n - 1][i] = V[i][i]; V[i][i] = 1; h = d[i + 1]; if (h !== 0) { for (k = 0; k <= i; k++) { d[k] = V[k][i + 1] / h; } for (j = 0; j <= i; j++) { g = 0; for (k = 0; k <= i; k++) { g += V[k][i + 1] * V[k][j]; } for (k = 0; k <= i; k++) { V[k][j] -= g * d[k]; } } } for (k = 0; k <= i; k++) { V[k][i + 1] = 0; } } for (j = 0; j < n; j++) { d[j] = V[n - 1][j]; V[n - 1][j] = 0; } V[n - 1][n - 1] = 1; e[0] = 0; } function tql2(n, e, d, V) { var g, h, i, j, k, l, m, p, r, dl1, c, c2, c3, el1, s, s2, iter; for (i = 1; i < n; i++) { e[i - 1] = e[i]; } e[n - 1] = 0; var f = 0, tst1 = 0, eps = Math.pow(2, -52); for (l = 0; l < n; l++) { tst1 = Math.max(tst1, Math.abs(d[l]) + Math.abs(e[l])); m = l; while (m < n) { if (Math.abs(e[m]) <= eps * tst1) { break; } m++; } if (m > l) { iter = 0; do { iter = iter + 1; g = d[l]; p = (d[l + 1] - g) / (2 * e[l]); r = hypotenuse(p, 1); if (p < 0) { r = -r; } d[l] = e[l] / (p + r); d[l + 1] = e[l] * (p + r); dl1 = d[l + 1]; h = g - d[l]; for (i = l + 2; i < n; i++) { d[i] -= h; } f = f + h; p = d[m]; c = 1; c2 = c; c3 = c; el1 = e[l + 1]; s = 0; s2 = 0; for (i = m - 1; i >= l; i--) { c3 = c2; c2 = c; s2 = s; g = c * e[i]; h = c * p; r = hypotenuse(p, e[i]); e[i + 1] = s * r; s = e[i] / r; c = p / r; p = c * d[i] - s * g; d[i + 1] = h + s * (c * g + s * d[i]); for (k = 0; k < n; k++) { h = V[k][i + 1]; V[k][i + 1] = s * V[k][i] + c * h; V[k][i] = c * V[k][i] - s * h; } } p = -s * s2 * c3 * el1 * e[l] / dl1; e[l] = s * p; d[l] = c * p; } while (Math.abs(e[l]) > eps * tst1); } d[l] = d[l] + f; e[l] = 0; } for (i = 0; i < n - 1; i++) { k = i; p = d[i]; for (j = i + 1; j < n; j++) { if (d[j] < p) { k = j; p = d[j]; } } if (k !== i) { d[k] = d[i]; d[i] = p; for (j = 0; j < n; j++) { p = V[j][i]; V[j][i] = V[j][k]; V[j][k] = p; } } } } function orthes(n, H, ort, V) { var low = 0, high = n - 1, f, g, h, i, j, m, scale; for (m = low + 1; m <= high - 1; m++) { scale = 0; for (i = m; i <= high; i++) { scale = scale + Math.abs(H[i][m - 1]); } if (scale !== 0) { h = 0; for (i = high; i >= m; i--) { ort[i] = H[i][m - 1] / scale; h += ort[i] * ort[i]; } g = Math.sqrt(h); if (ort[m] > 0) { g = -g; } h = h - ort[m] * g; ort[m] = ort[m] - g; for (j = m; j < n; j++) { f = 0; for (i = high; i >= m; i--) { f += ort[i] * H[i][j]; } f = f / h; for (i = m; i <= high; i++) { H[i][j] -= f * ort[i]; } } for (i = 0; i <= high; i++) { f = 0; for (j = high; j >= m; j--) { f += ort[j] * H[i][j]; } f = f / h; for (j = m; j <= high; j++) { H[i][j] -= f * ort[j]; } } ort[m] = scale * ort[m]; H[m][m - 1] = scale * g; } } for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { V[i][j] = (i === j ? 1 : 0); } } for (m = high - 1; m >= low + 1; m--) { if (H[m][m - 1] !== 0) { for (i = m + 1; i <= high; i++) { ort[i] = H[i][m - 1]; } for (j = m; j <= high; j++) { g = 0; for (i = m; i <= high; i++) { g += ort[i] * V[i][j]; } g = (g / ort[m]) / H[m][m - 1]; for (i = m; i <= high; i++) { V[i][j] += g * ort[i]; } } } } } function hqr2(nn, e, d, V, H) { var n = nn - 1, low = 0, high = nn - 1, eps = Math.pow(2, -52), exshift = 0, norm = 0, p = 0, q = 0, r = 0, s = 0, z = 0, iter = 0, i, j, k, l, m, t, w, x, y, ra, sa, vr, vi, notlast, cdivres; for (i = 0; i < nn; i++) { if (i < low || i > high) { d[i] = H[i][i]; e[i] = 0; } for (j = Math.max(i - 1, 0); j < nn; j++) { norm = norm + Math.abs(H[i][j]); } } while (n >= low) { l = n; while (l > low) { s = Math.abs(H[l - 1][l - 1]) + Math.abs(H[l][l]); if (s === 0) { s = norm; } if (Math.abs(H[l][l - 1]) < eps * s) { break; } l--; } if (l === n) { H[n][n] = H[n][n] + exshift; d[n] = H[n][n]; e[n] = 0; n--; iter = 0; } else if (l === n - 1) { w = H[n][n - 1] * H[n - 1][n]; p = (H[n - 1][n - 1] - H[n][n]) / 2; q = p * p + w; z = Math.sqrt(Math.abs(q)); H[n][n] = H[n][n] + exshift; H[n - 1][n - 1] = H[n - 1][n - 1] + exshift; x = H[n][n]; if (q >= 0) { z = (p >= 0) ? (p + z) : (p - z); d[n - 1] = x + z; d[n] = d[n - 1]; if (z !== 0) { d[n] = x - w / z; } e[n - 1] = 0; e[n] = 0; x = H[n][n - 1]; s = Math.abs(x) + Math.abs(z); p = x / s; q = z / s; r = Math.sqrt(p * p + q * q); p = p / r; q = q / r; for (j = n - 1; j < nn; j++) { z = H[n - 1][j]; H[n - 1][j] = q * z + p * H[n][j]; H[n][j] = q * H[n][j] - p * z; } for (i = 0; i <= n; i++) { z = H[i][n - 1]; H[i][n - 1] = q * z + p * H[i][n]; H[i][n] = q * H[i][n] - p * z; } for (i = low; i <= high; i++) { z = V[i][n - 1]; V[i][n - 1] = q * z + p * V[i][n]; V[i][n] = q * V[i][n] - p * z; } } else { d[n - 1] = x + p; d[n] = x + p; e[n - 1] = z; e[n] = -z; } n = n - 2; iter = 0; } else { x = H[n][n]; y = 0; w = 0; if (l < n) { y = H[n - 1][n - 1]; w = H[n][n - 1] * H[n - 1][n]; } if (iter === 10) { exshift += x; for (i = low; i <= n; i++) { H[i][i] -= x; } s = Math.abs(H[n][n - 1]) + Math.abs(H[n - 1][n - 2]); x = y = 0.75 * s; w = -0.4375 * s * s; } if (iter === 30) { s = (y - x) / 2; s = s * s + w; if (s > 0) { s = Math.sqrt(s); if (y < x) { s = -s; } s = x - w / ((y - x) / 2 + s); for (i = low; i <= n; i++) { H[i][i] -= s; } exshift += s; x = y = w = 0.964; } } iter = iter + 1; m = n - 2; while (m >= l) { z = H[m][m]; r = x - z; s = y - z; p = (r * s - w) / H[m + 1][m] + H[m][m + 1]; q = H[m + 1][m + 1] - z - r - s; r = H[m + 2][m + 1]; s = Math.abs(p) + Math.abs(q) + Math.abs(r); p = p / s; q = q / s; r = r / s; if (m === l) { break; } if (Math.abs(H[m][m - 1]) * (Math.abs(q) + Math.abs(r)) < eps * (Math.abs(p) * (Math.abs(H[m - 1][m - 1]) + Math.abs(z) + Math.abs(H[m + 1][m + 1])))) { break; } m--; } for (i = m + 2; i <= n; i++) { H[i][i - 2] = 0; if (i > m + 2) { H[i][i - 3] = 0; } } for (k = m; k <= n - 1; k++) { notlast = (k !== n - 1); if (k !== m) { p = H[k][k - 1]; q = H[k + 1][k - 1]; r = (notlast ? H[k + 2][k - 1] : 0); x = Math.abs(p) + Math.abs(q) + Math.abs(r); if (x !== 0) { p = p / x; q = q / x; r = r / x; } } if (x === 0) { break; } s = Math.sqrt(p * p + q * q + r * r); if (p < 0) { s = -s; } if (s !== 0) { if (k !== m) { H[k][k - 1] = -s * x; } else if (l !== m) { H[k][k - 1] = -H[k][k - 1]; } p = p + s; x = p / s; y = q / s; z = r / s; q = q / p; r = r / p; for (j = k; j < nn; j++) { p = H[k][j] + q * H[k + 1][j]; if (notlast) { p = p + r * H[k + 2][j]; H[k + 2][j] = H[k + 2][j] - p * z; } H[k][j] = H[k][j] - p * x; H[k + 1][j] = H[k + 1][j] - p * y; } for (i = 0; i <= Math.min(n, k + 3); i++) { p = x * H[i][k] + y * H[i][k + 1]; if (notlast) { p = p + z * H[i][k + 2]; H[i][k + 2] = H[i][k + 2] - p * r; } H[i][k] = H[i][k] - p; H[i][k + 1] = H[i][k + 1] - p * q; } for (i = low; i <= high; i++) { p = x * V[i][k] + y * V[i][k + 1]; if (notlast) { p = p + z * V[i][k + 2]; V[i][k + 2] = V[i][k + 2] - p * r; } V[i][k] = V[i][k] - p; V[i][k + 1] = V[i][k + 1] - p * q; } } } } } if (norm === 0) { return; } for (n = nn - 1; n >= 0; n--) { p = d[n]; q = e[n]; if (q === 0) { l = n; H[n][n] = 1; for (i = n - 1; i >= 0; i--) { w = H[i][i] - p; r = 0; for (j = l; j <= n; j++) { r = r + H[i][j] * H[j][n]; } if (e[i] < 0) { z = w; s = r; } else { l = i; if (e[i] === 0) { H[i][n] = (w !== 0) ? (-r / w) : (-r / (eps * norm)); } else { x = H[i][i + 1]; y = H[i + 1][i]; q = (d[i] - p) * (d[i] - p) + e[i] * e[i]; t = (x * s - z * r) / q; H[i][n] = t; H[i + 1][n] = (Math.abs(x) > Math.abs(z)) ? ((-r - w * t) / x) : ((-s - y * t) / z); } t = Math.abs(H[i][n]); if ((eps * t) * t > 1) { for (j = i; j <= n; j++) { H[j][n] = H[j][n] / t; } } } } } else if (q < 0) { l = n - 1; if (Math.abs(H[n][n - 1]) > Math.abs(H[n - 1][n])) { H[n - 1][n - 1] = q / H[n][n - 1]; H[n - 1][n] = -(H[n][n] - p) / H[n][n - 1]; } else { cdivres = cdiv(0, -H[n - 1][n], H[n - 1][n - 1] - p, q); H[n - 1][n - 1] = cdivres[0]; H[n - 1][n] = cdivres[1]; } H[n][n - 1] = 0; H[n][n] = 1; for (i = n - 2; i >= 0; i--) { ra = 0; sa = 0; for (j = l; j <= n; j++) { ra = ra + H[i][j] * H[j][n - 1]; sa = sa + H[i][j] * H[j][n]; } w = H[i][i] - p; if (e[i] < 0) { z = w; r = ra; s = sa; } else { l = i; if (e[i] === 0) { cdivres = cdiv(-ra, -sa, w, q); H[i][n - 1] = cdivres[0]; H[i][n] = cdivres[1]; } else { x = H[i][i + 1]; y = H[i + 1][i]; vr = (d[i] - p) * (d[i] - p) + e[i] * e[i] - q * q; vi = (d[i] - p) * 2 * q; if (vr === 0 && vi === 0) { vr = eps * norm * (Math.abs(w) + Math.abs(q) + Math.abs(x) + Math.abs(y) + Math.abs(z)); } cdivres = cdiv(x * r - z * ra + q * sa, x * s - z * sa - q * ra, vr, vi); H[i][n - 1] = cdivres[0]; H[i][n] = cdivres[1]; if (Math.abs(x) > (Math.abs(z) + Math.abs(q))) { H[i + 1][n - 1] = (-ra - w * H[i][n - 1] + q * H[i][n]) / x; H[i + 1][n] = (-sa - w * H[i][n] - q * H[i][n - 1]) / x; } else { cdivres = cdiv(-r - y * H[i][n - 1], -s - y * H[i][n], z, q); H[i + 1][n - 1] = cdivres[0]; H[i + 1][n] = cdivres[1]; } } t = Math.max(Math.abs(H[i][n - 1]), Math.abs(H[i][n])); if ((eps * t) * t > 1) { for (j = i; j <= n; j++) { H[j][n - 1] = H[j][n - 1] / t; H[j][n] = H[j][n] / t; } } } } } } for (i = 0; i < nn; i++) { if (i < low || i > high) { for (j = i; j < nn; j++) { V[i][j] = H[i][j]; } } } for (j = nn - 1; j >= low; j--) { for (i = low; i <= high; i++) { z = 0; for (k = low; k <= Math.min(j, high); k++) { z = z + V[i][k] * H[k][j]; } V[i][j] = z; } } } function cdiv(xr, xi, yr, yi) { var r, d; if (Math.abs(yr) > Math.abs(yi)) { r = yi / yr; d = yr + r * yi; return [(xr + r * xi) / d, (xi - r * xr) / d]; } else { r = yr / yi; d = yi + r * yr; return [(r * xr + xi) / d, (r * xi - xr) / d]; } } module.exports = EigenvalueDecomposition;