| /* |
| * R : A Computer Language for Statistical Data Analysis |
| * Copyright (C) 2004 The R Core Team. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, a copy is available at |
| * https://www.R-project.org/Licenses/ |
| */ |
| |
| #include "modreg.h" /* for declarations for registration */ |
| |
| void kmeans_Lloyd(double *x, int *pn, int *pp, double *cen, int *pk, int *cl, |
| int *pmaxiter, int *nc, double *wss) |
| { |
| int n = *pn, k = *pk, p = *pp, maxiter = *pmaxiter; |
| int iter, i, j, c, it, inew = 0; |
| double best, dd, tmp; |
| Rboolean updated; |
| |
| for(i = 0; i < n; i++) cl[i] = -1; |
| for(iter = 0; iter < maxiter; iter++) { |
| updated = FALSE; |
| for(i = 0; i < n; i++) { |
| /* find nearest centre for each point */ |
| best = R_PosInf; |
| for(j = 0; j < k; j++) { |
| dd = 0.0; |
| for(c = 0; c < p; c++) { |
| tmp = x[i+n*c] - cen[j+k*c]; |
| dd += tmp * tmp; |
| } |
| if(dd < best) { |
| best = dd; |
| inew = j+1; |
| } |
| } |
| if(cl[i] != inew) { |
| updated = TRUE; |
| cl[i] = inew; |
| } |
| } |
| if(!updated) break; |
| /* update each centre */ |
| for(j = 0; j < k*p; j++) cen[j] = 0.0; |
| for(j = 0; j < k; j++) nc[j] = 0; |
| for(i = 0; i < n; i++) { |
| it = cl[i] - 1; nc[it]++; |
| for(c = 0; c < p; c++) cen[it+c*k] += x[i+c*n]; |
| } |
| for(j = 0; j < k*p; j++) cen[j] /= nc[j % k]; |
| } |
| |
| *pmaxiter = iter + 1; |
| for(j = 0; j < k; j++) wss[j] = 0.0; |
| for(i = 0; i < n; i++) { |
| it = cl[i] - 1; |
| for(c = 0; c < p; c++) { |
| tmp = x[i+n*c] - cen[it+k*c]; |
| wss[it] += tmp * tmp; |
| } |
| } |
| } |
| |
| void kmeans_MacQueen(double *x, int *pn, int *pp, double *cen, int *pk, |
| int *cl, int *pmaxiter, int *nc, double *wss) |
| { |
| int n = *pn, k = *pk, p = *pp, maxiter = *pmaxiter; |
| int iter, i, j, c, it, inew = 0, iold; |
| double best, dd, tmp; |
| Rboolean updated; |
| |
| /* first assign each point to the nearest cluster centre */ |
| for(i = 0; i < n; i++) { |
| best = R_PosInf; |
| for(j = 0; j < k; j++) { |
| dd = 0.0; |
| for(c = 0; c < p; c++) { |
| tmp = x[i+n*c] - cen[j+k*c]; |
| dd += tmp * tmp; |
| } |
| if(dd < best) { |
| best = dd; |
| inew = j+1; |
| } |
| } |
| if(cl[i] != inew) cl[i] = inew; |
| } |
| /* and recompute centres as centroids */ |
| for(j = 0; j < k*p; j++) cen[j] = 0.0; |
| for(j = 0; j < k; j++) nc[j] = 0; |
| for(i = 0; i < n; i++) { |
| it = cl[i] - 1; nc[it]++; |
| for(c = 0; c < p; c++) cen[it+c*k] += x[i+c*n]; |
| } |
| for(j = 0; j < k*p; j++) cen[j] /= nc[j % k]; |
| |
| for(iter = 0; iter < maxiter; iter++) { |
| updated = FALSE; |
| for(i = 0; i < n; i++) { |
| best = R_PosInf; |
| for(j = 0; j < k; j++) { |
| dd = 0.0; |
| for(c = 0; c < p; c++) { |
| tmp = x[i+n*c] - cen[j+k*c]; |
| dd += tmp * tmp; |
| } |
| if(dd < best) { |
| best = dd; |
| inew = j; |
| } |
| } |
| if((iold = cl[i] - 1) != inew) { |
| updated = TRUE; |
| cl[i] = inew + 1; |
| nc[iold]--; nc[inew]++; |
| /* update old and new cluster centres */ |
| for(c = 0; c < p; c++) { |
| cen[iold+k*c] += (cen[iold+k*c] - x[i+n*c])/nc[iold]; |
| cen[inew+k*c] += (x[i+n*c] - cen[inew+k*c])/nc[inew]; |
| } |
| } |
| } |
| if(!updated) break; |
| } |
| |
| *pmaxiter = iter + 1; |
| for(j = 0; j < k; j++) wss[j] = 0.0; |
| for(i = 0; i < n; i++) { |
| it = cl[i] - 1; |
| for(c = 0; c < p; c++) { |
| tmp = x[i+n*c] - cen[it+k*c]; |
| wss[it] += tmp * tmp; |
| } |
| } |
| } |
| |
| // tracing for kmeans() in ./kmns.f |
| |
| void F77_SUB(kmns1)(int *k, int *it, int *indx) { |
| Rprintf("KMNS(*, k=%d): iter=%3d, indx=%d\n", *k, *it, *indx); |
| } |
| |
| void F77_SUB(kmnsqpr)(int *istep, int *icoun, int *NCP, int *k, int *trace) |
| { |
| Rprintf(" QTRAN(): istep=%d, icoun=%d", *istep, *icoun); |
| if(*trace >= 2) { |
| Rprintf(", NCP[1:%d]=", k[0]); |
| for(int i=0; i < k[0]; i++) Rprintf(" %d", NCP[i]); |
| } |
| Rprintf("\n"); |
| } |
| |