csPermute.js (1723B)
1 "use strict"; 2 3 Object.defineProperty(exports, "__esModule", { 4 value: true 5 }); 6 exports.csPermute = csPermute; 7 8 /** 9 * Permutes a sparse matrix C = P * A * Q 10 * 11 * @param {SparseMatrix} a The Matrix A 12 * @param {Array} pinv The row permutation vector 13 * @param {Array} q The column permutation vector 14 * @param {boolean} values Create a pattern matrix (false), values and pattern otherwise 15 * 16 * @return {Matrix} C = P * A * Q, null on error 17 * 18 * Reference: http://faculty.cse.tamu.edu/davis/publications.html 19 */ 20 function csPermute(a, pinv, q, values) { 21 // a arrays 22 var avalues = a._values; 23 var aindex = a._index; 24 var aptr = a._ptr; 25 var asize = a._size; 26 var adt = a._datatype; // rows & columns 27 28 var m = asize[0]; 29 var n = asize[1]; // c arrays 30 31 var cvalues = values && a._values ? [] : null; 32 var cindex = []; // (aptr[n]) 33 34 var cptr = []; // (n + 1) 35 // initialize vars 36 37 var nz = 0; // loop columns 38 39 for (var k = 0; k < n; k++) { 40 // column k of C is column q[k] of A 41 cptr[k] = nz; // apply column permutation 42 43 var j = q ? q[k] : k; // loop values in column j of A 44 45 for (var t0 = aptr[j], t1 = aptr[j + 1], t = t0; t < t1; t++) { 46 // row i of A is row pinv[i] of C 47 var r = pinv ? pinv[aindex[t]] : aindex[t]; // index 48 49 cindex[nz] = r; // check we need to populate values 50 51 if (cvalues) { 52 cvalues[nz] = avalues[t]; 53 } // increment number of nonzero elements 54 55 56 nz++; 57 } 58 } // finalize the last column of C 59 60 61 cptr[n] = nz; // return C matrix 62 63 return a.createSparseMatrix({ 64 values: cvalues, 65 index: cindex, 66 ptr: cptr, 67 size: [m, n], 68 datatype: adt 69 }); 70 }