jiangchengfeiyi-xiaochengxu/node_modules/mathjs/lib/cjs/function/matrix/eigs/realSymmetric.js

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2025-01-02 03:13:50 +00:00
"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.createRealSymmetric = createRealSymmetric;
var _object = require("../../../utils/object.js");
function createRealSymmetric(_ref) {
let {
config,
addScalar,
subtract,
abs,
atan,
cos,
sin,
multiplyScalar,
inv,
bignumber,
multiply,
add
} = _ref;
/**
* @param {number[] | BigNumber[]} arr
* @param {number} N
* @param {number} prec
* @param {'number' | 'BigNumber'} type
*/
function main(arr, N) {
let prec = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : config.relTol;
let type = arguments.length > 3 ? arguments[3] : undefined;
let computeVectors = arguments.length > 4 ? arguments[4] : undefined;
if (type === 'number') {
return diag(arr, prec, computeVectors);
}
if (type === 'BigNumber') {
return diagBig(arr, prec, computeVectors);
}
throw TypeError('Unsupported data type: ' + type);
}
// diagonalization implementation for number (efficient)
function diag(x, precision, computeVectors) {
const N = x.length;
const e0 = Math.abs(precision / N);
let psi;
let Sij;
if (computeVectors) {
Sij = new Array(N);
// Sij is Identity Matrix
for (let i = 0; i < N; i++) {
Sij[i] = Array(N).fill(0);
Sij[i][i] = 1.0;
}
}
// initial error
let Vab = getAij(x);
while (Math.abs(Vab[1]) >= Math.abs(e0)) {
const i = Vab[0][0];
const j = Vab[0][1];
psi = getTheta(x[i][i], x[j][j], x[i][j]);
x = x1(x, psi, i, j);
if (computeVectors) Sij = Sij1(Sij, psi, i, j);
Vab = getAij(x);
}
const Ei = Array(N).fill(0); // eigenvalues
for (let i = 0; i < N; i++) {
Ei[i] = x[i][i];
}
return sorting((0, _object.clone)(Ei), Sij, computeVectors);
}
// diagonalization implementation for bigNumber
function diagBig(x, precision, computeVectors) {
const N = x.length;
const e0 = abs(precision / N);
let psi;
let Sij;
if (computeVectors) {
Sij = new Array(N);
// Sij is Identity Matrix
for (let i = 0; i < N; i++) {
Sij[i] = Array(N).fill(0);
Sij[i][i] = 1.0;
}
}
// initial error
let Vab = getAijBig(x);
while (abs(Vab[1]) >= abs(e0)) {
const i = Vab[0][0];
const j = Vab[0][1];
psi = getThetaBig(x[i][i], x[j][j], x[i][j]);
x = x1Big(x, psi, i, j);
if (computeVectors) Sij = Sij1Big(Sij, psi, i, j);
Vab = getAijBig(x);
}
const Ei = Array(N).fill(0); // eigenvalues
for (let i = 0; i < N; i++) {
Ei[i] = x[i][i];
}
// return [clone(Ei), clone(Sij)]
return sorting((0, _object.clone)(Ei), Sij, computeVectors);
}
// get angle
function getTheta(aii, ajj, aij) {
const denom = ajj - aii;
if (Math.abs(denom) <= config.relTol) {
return Math.PI / 4.0;
} else {
return 0.5 * Math.atan(2.0 * aij / (ajj - aii));
}
}
// get angle
function getThetaBig(aii, ajj, aij) {
const denom = subtract(ajj, aii);
if (abs(denom) <= config.relTol) {
return bignumber(-1).acos().div(4);
} else {
return multiplyScalar(0.5, atan(multiply(2.0, aij, inv(denom))));
}
}
// update eigvec
function Sij1(Sij, theta, i, j) {
const N = Sij.length;
const c = Math.cos(theta);
const s = Math.sin(theta);
const Ski = Array(N).fill(0);
const Skj = Array(N).fill(0);
for (let k = 0; k < N; k++) {
Ski[k] = c * Sij[k][i] - s * Sij[k][j];
Skj[k] = s * Sij[k][i] + c * Sij[k][j];
}
for (let k = 0; k < N; k++) {
Sij[k][i] = Ski[k];
Sij[k][j] = Skj[k];
}
return Sij;
}
// update eigvec for overlap
function Sij1Big(Sij, theta, i, j) {
const N = Sij.length;
const c = cos(theta);
const s = sin(theta);
const Ski = Array(N).fill(bignumber(0));
const Skj = Array(N).fill(bignumber(0));
for (let k = 0; k < N; k++) {
Ski[k] = subtract(multiplyScalar(c, Sij[k][i]), multiplyScalar(s, Sij[k][j]));
Skj[k] = addScalar(multiplyScalar(s, Sij[k][i]), multiplyScalar(c, Sij[k][j]));
}
for (let k = 0; k < N; k++) {
Sij[k][i] = Ski[k];
Sij[k][j] = Skj[k];
}
return Sij;
}
// update matrix
function x1Big(Hij, theta, i, j) {
const N = Hij.length;
const c = bignumber(cos(theta));
const s = bignumber(sin(theta));
const c2 = multiplyScalar(c, c);
const s2 = multiplyScalar(s, s);
const Aki = Array(N).fill(bignumber(0));
const Akj = Array(N).fill(bignumber(0));
// 2cs Hij
const csHij = multiply(bignumber(2), c, s, Hij[i][j]);
// Aii
const Aii = addScalar(subtract(multiplyScalar(c2, Hij[i][i]), csHij), multiplyScalar(s2, Hij[j][j]));
const Ajj = add(multiplyScalar(s2, Hij[i][i]), csHij, multiplyScalar(c2, Hij[j][j]));
// 0 to i
for (let k = 0; k < N; k++) {
Aki[k] = subtract(multiplyScalar(c, Hij[i][k]), multiplyScalar(s, Hij[j][k]));
Akj[k] = addScalar(multiplyScalar(s, Hij[i][k]), multiplyScalar(c, Hij[j][k]));
}
// Modify Hij
Hij[i][i] = Aii;
Hij[j][j] = Ajj;
Hij[i][j] = bignumber(0);
Hij[j][i] = bignumber(0);
// 0 to i
for (let k = 0; k < N; k++) {
if (k !== i && k !== j) {
Hij[i][k] = Aki[k];
Hij[k][i] = Aki[k];
Hij[j][k] = Akj[k];
Hij[k][j] = Akj[k];
}
}
return Hij;
}
// update matrix
function x1(Hij, theta, i, j) {
const N = Hij.length;
const c = Math.cos(theta);
const s = Math.sin(theta);
const c2 = c * c;
const s2 = s * s;
const Aki = Array(N).fill(0);
const Akj = Array(N).fill(0);
// Aii
const Aii = c2 * Hij[i][i] - 2 * c * s * Hij[i][j] + s2 * Hij[j][j];
const Ajj = s2 * Hij[i][i] + 2 * c * s * Hij[i][j] + c2 * Hij[j][j];
// 0 to i
for (let k = 0; k < N; k++) {
Aki[k] = c * Hij[i][k] - s * Hij[j][k];
Akj[k] = s * Hij[i][k] + c * Hij[j][k];
}
// Modify Hij
Hij[i][i] = Aii;
Hij[j][j] = Ajj;
Hij[i][j] = 0;
Hij[j][i] = 0;
// 0 to i
for (let k = 0; k < N; k++) {
if (k !== i && k !== j) {
Hij[i][k] = Aki[k];
Hij[k][i] = Aki[k];
Hij[j][k] = Akj[k];
Hij[k][j] = Akj[k];
}
}
return Hij;
}
// get max off-diagonal value from Upper Diagonal
function getAij(Mij) {
const N = Mij.length;
let maxMij = 0;
let maxIJ = [0, 1];
for (let i = 0; i < N; i++) {
for (let j = i + 1; j < N; j++) {
if (Math.abs(maxMij) < Math.abs(Mij[i][j])) {
maxMij = Math.abs(Mij[i][j]);
maxIJ = [i, j];
}
}
}
return [maxIJ, maxMij];
}
// get max off-diagonal value from Upper Diagonal
function getAijBig(Mij) {
const N = Mij.length;
let maxMij = 0;
let maxIJ = [0, 1];
for (let i = 0; i < N; i++) {
for (let j = i + 1; j < N; j++) {
if (abs(maxMij) < abs(Mij[i][j])) {
maxMij = abs(Mij[i][j]);
maxIJ = [i, j];
}
}
}
return [maxIJ, maxMij];
}
// sort results
function sorting(E, S, computeVectors) {
const N = E.length;
const values = Array(N);
let vecs;
if (computeVectors) {
vecs = Array(N);
for (let k = 0; k < N; k++) {
vecs[k] = Array(N);
}
}
for (let i = 0; i < N; i++) {
let minID = 0;
let minE = E[0];
for (let j = 0; j < E.length; j++) {
if (abs(E[j]) < abs(minE)) {
minID = j;
minE = E[minID];
}
}
values[i] = E.splice(minID, 1)[0];
if (computeVectors) {
for (let k = 0; k < N; k++) {
vecs[i][k] = S[k][minID];
S[k].splice(minID, 1);
}
}
}
if (!computeVectors) return {
values
};
const eigenvectors = vecs.map((vector, i) => ({
value: values[i],
vector
}));
return {
values,
eigenvectors
};
}
return main;
}