jiangchengfeiyi-xiaochengxu/node_modules/mathjs/lib/cjs/function/algebra/sparse/csCounts.js
2025-01-02 11:13:50 +08:00

133 lines
3.7 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.createCsCounts = void 0;
var _factory = require("../../../utils/factory.js");
var _csLeaf = require("./csLeaf.js");
// Copyright (c) 2006-2024, Timothy A. Davis, All Rights Reserved.
// SPDX-License-Identifier: LGPL-2.1+
// https://github.com/DrTimothyAldenDavis/SuiteSparse/tree/dev/CSparse/Source
const name = 'csCounts';
const dependencies = ['transpose'];
const createCsCounts = exports.createCsCounts = /* #__PURE__ */(0, _factory.factory)(name, dependencies, _ref => {
let {
transpose
} = _ref;
/**
* Computes the column counts using the upper triangular part of A.
* It transposes A internally, none of the input parameters are modified.
*
* @param {Matrix} a The sparse matrix A
*
* @param {Matrix} ata Count the columns of A'A instead
*
* @return An array of size n of the column counts or null on error
*/
return function (a, parent, post, ata) {
// check inputs
if (!a || !parent || !post) {
return null;
}
// a matrix arrays
const asize = a._size;
// rows and columns
const m = asize[0];
const n = asize[1];
// variables
let i, j, k, J, p, p0, p1;
// workspace size
const s = 4 * n + (ata ? n + m + 1 : 0);
// allocate workspace
const w = []; // (s)
const ancestor = 0; // first n entries
const maxfirst = n; // next n entries
const prevleaf = 2 * n; // next n entries
const first = 3 * n; // next n entries
const head = 4 * n; // next n + 1 entries (used when ata is true)
const next = 5 * n + 1; // last entries in workspace
// clear workspace w[0..s-1]
for (k = 0; k < s; k++) {
w[k] = -1;
}
// allocate result
const colcount = []; // (n)
// AT = A'
const at = transpose(a);
// at arrays
const tindex = at._index;
const tptr = at._ptr;
// find w[first + j]
for (k = 0; k < n; k++) {
j = post[k];
// colcount[j]=1 if j is a leaf
colcount[j] = w[first + j] === -1 ? 1 : 0;
for (; j !== -1 && w[first + j] === -1; j = parent[j]) {
w[first + j] = k;
}
}
// initialize ata if needed
if (ata) {
// invert post
for (k = 0; k < n; k++) {
w[post[k]] = k;
}
// loop rows (columns in AT)
for (i = 0; i < m; i++) {
// values in column i of AT
for (k = n, p0 = tptr[i], p1 = tptr[i + 1], p = p0; p < p1; p++) {
k = Math.min(k, w[tindex[p]]);
}
// place row i in linked list k
w[next + i] = w[head + k];
w[head + k] = i;
}
}
// each node in its own set
for (i = 0; i < n; i++) {
w[ancestor + i] = i;
}
for (k = 0; k < n; k++) {
// j is the kth node in postordered etree
j = post[k];
// check j is not a root
if (parent[j] !== -1) {
colcount[parent[j]]--;
}
// J=j for LL'=A case
for (J = ata ? w[head + k] : j; J !== -1; J = ata ? w[next + J] : -1) {
for (p = tptr[J]; p < tptr[J + 1]; p++) {
i = tindex[p];
const r = (0, _csLeaf.csLeaf)(i, j, w, first, maxfirst, prevleaf, ancestor);
// check A(i,j) is in skeleton
if (r.jleaf >= 1) {
colcount[j]++;
}
// check account for overlap in q
if (r.jleaf === 2) {
colcount[r.q]--;
}
}
}
if (parent[j] !== -1) {
w[ancestor + j] = parent[j];
}
}
// sum up colcount's of each child
for (j = 0; j < n; j++) {
if (parent[j] !== -1) {
colcount[parent[j]] += colcount[j];
}
}
return colcount;
};
});