1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796
|
//
// communitytype.cpp
// Mothur
//
// Created by SarahsWork on 12/3/13.
// Copyright (c) 2013 Schloss Lab. All rights reserved.
//
#include "communitytype.h"
/**************************************************************************************************/
//can we get these psi/psi1 calculations into their own math class?
//psi calcualtions swiped from gsl library...
static const double psi_cs[23] = {
-.038057080835217922,
.491415393029387130,
-.056815747821244730,
.008357821225914313,
-.001333232857994342,
.000220313287069308,
-.000037040238178456,
.000006283793654854,
-.000001071263908506,
.000000183128394654,
-.000000031353509361,
.000000005372808776,
-.000000000921168141,
.000000000157981265,
-.000000000027098646,
.000000000004648722,
-.000000000000797527,
.000000000000136827,
-.000000000000023475,
.000000000000004027,
-.000000000000000691,
.000000000000000118,
-.000000000000000020
};
static double apsi_cs[16] = {
-.0204749044678185,
-.0101801271534859,
.0000559718725387,
-.0000012917176570,
.0000000572858606,
-.0000000038213539,
.0000000003397434,
-.0000000000374838,
.0000000000048990,
-.0000000000007344,
.0000000000001233,
-.0000000000000228,
.0000000000000045,
-.0000000000000009,
.0000000000000002,
-.0000000000000000
};
/**************************************************************************************************/
/* coefficients for Maclaurin summation in hzeta()
* B_{2j}/(2j)!
*/
static double hzeta_c[15] = {
1.00000000000000000000000000000,
0.083333333333333333333333333333,
-0.00138888888888888888888888888889,
0.000033068783068783068783068783069,
-8.2671957671957671957671957672e-07,
2.0876756987868098979210090321e-08,
-5.2841901386874931848476822022e-10,
1.3382536530684678832826980975e-11,
-3.3896802963225828668301953912e-13,
8.5860620562778445641359054504e-15,
-2.1748686985580618730415164239e-16,
5.5090028283602295152026526089e-18,
-1.3954464685812523340707686264e-19,
3.5347070396294674716932299778e-21,
-8.9535174270375468504026113181e-23
};
/**************************************************************************************************/
void CommunityTypeFinder::printSilData(ofstream& out, double chi, vector<double> sils){
try {
out << setprecision (6) << numPartitions << '\t' << chi;
for (int i = 0; i < sils.size(); i++) {
out << '\t' << sils[i];
}
out << endl;
return;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "printSilData");
exit(1);
}
}
/**************************************************************************************************/
void CommunityTypeFinder::printSilData(ostream& out, double chi, vector<double> sils){
try {
out << setprecision (6) << numPartitions << '\t' << chi;
m->mothurOutJustToLog(toString(numPartitions) + '\t' + toString(chi));
for (int i = 0; i < sils.size(); i++) {
out << '\t' << sils[i];
m->mothurOutJustToLog("\t" + toString(sils[i]));
}
out << endl;
m->mothurOutJustToLog("\n");
return;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "printSilData");
exit(1);
}
}
/**************************************************************************************************/
void CommunityTypeFinder::printZMatrix(string fileName, vector<string> sampleName){
try {
ofstream printMatrix;
util.openOutputFile(fileName, printMatrix); //(fileName.c_str());
printMatrix.setf(ios::fixed, ios::floatfield);
printMatrix.setf(ios::showpoint);
for(int i=0;i<numPartitions;i++){ printMatrix << "\tPartition_" << i+1; } printMatrix << endl;
for(int i=0;i<numSamples;i++){
printMatrix << sampleName[i];
for(int j=0;j<numPartitions;j++){
printMatrix << setprecision(4) << '\t' << zMatrix[j][i];
}
printMatrix << endl;
}
printMatrix.close();
}
catch(exception& e) {
m->errorOut(e, "CommunityTypeFinder", "printZMatrix");
exit(1);
}
}
/**************************************************************************************************/
void CommunityTypeFinder::printRelAbund(string fileName, vector<string> otuNames){
try {
ofstream printRA;
util.openOutputFile(fileName, printRA); //(fileName.c_str());
printRA.setf(ios::fixed, ios::floatfield);
printRA.setf(ios::showpoint);
vector<double> totals(numPartitions, 0.0000);
for(int i=0;i<numPartitions;i++){
for(int j=0;j<numOTUs;j++){
totals[i] += exp(lambdaMatrix[i][j]);
}
}
printRA << "Taxon";
for(int i=0;i<numPartitions;i++){
printRA << "\tPartition_" << i+1 << '_' << setprecision(4) << totals[i];
printRA << "\tPartition_" << i+1 <<"_LCI" << "\tPartition_" << i+1 << "_UCI";
}
printRA << endl;
for(int i=0;i<numOTUs;i++){
if (m->getControl_pressed()) { break; }
printRA << otuNames[i];
for(int j=0;j<numPartitions;j++){
if(error[j][i] >= 0.0000){
double std = sqrt(error[j][i]);
printRA << '\t' << 100 * exp(lambdaMatrix[j][i]) / totals[j];
printRA << '\t' << 100 * exp(lambdaMatrix[j][i] - 2.0 * std) / totals[j];
printRA << '\t' << 100 * exp(lambdaMatrix[j][i] + 2.0 * std) / totals[j];
}
else{
printRA << '\t' << 100 * exp(lambdaMatrix[j][i]) / totals[j];
printRA << '\t' << "NA";
printRA << '\t' << "NA";
}
}
printRA << endl;
}
printRA.close();
}
catch(exception& e) {
m->errorOut(e, "CommunityTypeFinder", "printRelAbund");
exit(1);
}
}
/**************************************************************************************************/
vector<vector<double> > CommunityTypeFinder::getHessian(){
try {
vector<double> alpha(numOTUs, 0.0000);
double alphaSum = 0.0000;
vector<double> pi = zMatrix[currentPartition];
vector<double> psi_ajk(numOTUs, 0.0000);
vector<double> psi_cjk(numOTUs, 0.0000);
vector<double> psi1_ajk(numOTUs, 0.0000);
vector<double> psi1_cjk(numOTUs, 0.0000);
for(int j=0;j<numOTUs;j++){
if (m->getControl_pressed()) { break; }
alpha[j] = exp(lambdaMatrix[currentPartition][j]);
alphaSum += alpha[j];
for(int i=0;i<numSamples;i++){
double X = (double) countMatrix[i][j];
psi_ajk[j] += pi[i] * psi(alpha[j]);
psi1_ajk[j] += pi[i] * psi1(alpha[j]);
psi_cjk[j] += pi[i] * psi(alpha[j] + X);
psi1_cjk[j] += pi[i] * psi1(alpha[j] + X);
}
}
double psi_Ck = 0.0000;
double psi1_Ck = 0.0000;
double weight = 0.0000;
for(int i=0;i<numSamples;i++){
if (m->getControl_pressed()) { break; }
weight += pi[i];
double sum = 0.0000;
for(int j=0;j<numOTUs;j++){ sum += alpha[j] + countMatrix[i][j]; }
psi_Ck += pi[i] * psi(sum);
psi1_Ck += pi[i] * psi1(sum);
}
double psi_Ak = weight * psi(alphaSum);
double psi1_Ak = weight * psi1(alphaSum);
vector<vector<double> > hessian(numOTUs);
for(int i=0;i<numOTUs;i++){ hessian[i].assign(numOTUs, 0.0000); }
for(int i=0;i<numOTUs;i++){
if (m->getControl_pressed()) { break; }
double term1 = -alpha[i] * (- psi_ajk[i] + psi_Ak + psi_cjk[i] - psi_Ck);
double term2 = -alpha[i] * alpha[i] * (-psi1_ajk[i] + psi1_Ak + psi1_cjk[i] - psi1_Ck);
double term3 = 0.1 * alpha[i];
hessian[i][i] = term1 + term2 + term3;
for(int j=0;j<i;j++){
hessian[i][j] = - alpha[i] * alpha[j] * (psi1_Ak - psi1_Ck);
hessian[j][i] = hessian[i][j];
}
}
return hessian;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "getHessian");
exit(1);
}
}
/**************************************************************************************************/
double CommunityTypeFinder::psi1(double xx){
try {
/* Euler-Maclaurin summation formula
* [Moshier, p. 400, with several typo corrections]
*/
double s = 2.0000;
const int jmax = 12;
const int kmax = 10;
int j, k;
const double pmax = pow(kmax + xx, -s);
double scp = s;
double pcp = pmax / (kmax + xx);
double value = pmax*((kmax+xx)/(s-1.0) + 0.5);
for(k=0; k<kmax; k++) {
if (m->getControl_pressed()) { return 0; }
value += pow(k + xx, -s);
}
for(j=0; j<=jmax; j++) {
if (m->getControl_pressed()) { return 0; }
double delta = hzeta_c[j+1] * scp * pcp;
value += delta;
if(fabs(delta/value) < 0.5*EPSILON) break;
scp *= (s+2*j+1)*(s+2*j+2);
pcp /= (kmax + xx)*(kmax + xx);
}
return value;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "psi1");
exit(1);
}
}
/**************************************************************************************************/
double CommunityTypeFinder::psi(double xx){
try {
double psiX = 0.0000;
if(xx < 1.0000){
double t1 = 1.0 / xx;
psiX = cheb_eval(psi_cs, 22, 2.0*xx-1.0);
psiX = -t1 + psiX;
}
else if(xx < 2.0000){
const double v = xx - 1.0;
psiX = cheb_eval(psi_cs, 22, 2.0*v-1.0);
}
else{
const double t = 8.0/(xx*xx)-1.0;
psiX = cheb_eval(apsi_cs, 15, t);
psiX += log(xx) - 0.5/xx;
}
return psiX;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "psi");
exit(1);
}
}
/**************************************************************************************************/
double CommunityTypeFinder::cheb_eval(const double seriesData[], int order, double xx){
try {
double d = 0.0000;
double dd = 0.0000;
double x2 = xx * 2.0000;
for(int j=order;j>=1;j--){
if (m->getControl_pressed()) { return 0; }
double temp = d;
d = x2 * d - dd + seriesData[j];
dd = temp;
}
d = xx * d - dd + 0.5 * seriesData[0];
return d;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "cheb_eval");
exit(1);
}
}
/**************************************************************************************************/
int CommunityTypeFinder::findkMeans(){
try {
error.resize(numPartitions); for (int i = 0; i < numPartitions; i++) { error[i].resize(numOTUs, 0.0); }
vector<vector<double> > relativeAbundance(numSamples);
vector<vector<double> > alphaMatrix;
alphaMatrix.resize(numPartitions);
lambdaMatrix.resize(numPartitions);
for(int i=0;i<numPartitions;i++){
alphaMatrix[i].assign(numOTUs, 0);
lambdaMatrix[i].assign(numOTUs, 0);
}
//get relative abundance
for(int i=0;i<numSamples;i++){
if (m->getControl_pressed()) { return 0; }
int groupTotal = 0;
relativeAbundance[i].assign(numOTUs, 0.0);
for(int j=0;j<numOTUs;j++){
groupTotal += countMatrix[i][j];
}
for(int j=0;j<numOTUs;j++){
relativeAbundance[i][j] = countMatrix[i][j] / (double)groupTotal;
}
}
//randomly assign samples into partitions
zMatrix.resize(numPartitions);
for(int i=0;i<numPartitions;i++){ zMatrix[i].assign(numSamples, 0); }
//randomize samples
vector<int> temp;
for (int i = 0; i < numSamples; i++) { temp.push_back(i); }
util.mothurRandomShuffle(temp);
//assign each partition at least one random sample
int numAssignedSamples = 0;
for (int i = 0; i < numPartitions; i++) {
zMatrix[i][temp[numAssignedSamples]] = 1;
numAssignedSamples++;
}
//assign rest of samples to partitions
int count = 0;
for(int i=numAssignedSamples;i<numSamples;i++){
zMatrix[count%numPartitions][temp[i]] = 1;
count++;
}
double maxChange = 1;
int maxIters = 1000;
int iteration = 0;
weights.assign(numPartitions, 0);
while(maxChange > 1e-6 && iteration < maxIters){
if (m->getControl_pressed()) { return 0; }
//calcualte average relative abundance
maxChange = 0.0000;
for(int i=0;i<numPartitions;i++){
double normChange = 0.0;
weights[i] = 0;
for(int j=0;j<numSamples;j++){
weights[i] += (double)zMatrix[i][j];
}
vector<double> averageRelativeAbundance(numOTUs, 0);
for(int j=0;j<numOTUs;j++){
for(int k=0;k<numSamples;k++){
averageRelativeAbundance[j] += zMatrix[i][k] * relativeAbundance[k][j];
}
}
for(int j=0;j<numOTUs;j++){
averageRelativeAbundance[j] /= weights[i];
double difference = averageRelativeAbundance[j] - alphaMatrix[i][j];
normChange += difference * difference;
alphaMatrix[i][j] = averageRelativeAbundance[j];
}
normChange = sqrt(normChange);
if(normChange > maxChange){ maxChange = normChange; }
}
//calcualte distance between each sample in partition and the average relative abundance
for(int i=0;i<numSamples;i++){
if (m->getControl_pressed()) { return 0; }
double normalizationFactor = 0;
vector<double> totalDistToPartition(numPartitions, 0);
for(int j=0;j<numPartitions;j++){
for(int k=0;k<numOTUs;k++){
double difference = alphaMatrix[j][k] - relativeAbundance[i][k];
totalDistToPartition[j] += difference * difference;
}
totalDistToPartition[j] = sqrt(totalDistToPartition[j]);
normalizationFactor += exp(-50.0 * totalDistToPartition[j]);
}
for(int j=0;j<numPartitions;j++){
zMatrix[j][i] = exp(-50.0 * totalDistToPartition[j]) / normalizationFactor;
}
}
iteration++;
}
for(int i=0;i<numPartitions;i++){ weights[i] = 0.0000; for(int j=0;j<numSamples;j++){ weights[i] += zMatrix[i][j]; } }
for(int i=0;i<numOTUs;i++){
if (m->getControl_pressed()) { return 0; }
for(int j=0;j<numPartitions;j++){
if(alphaMatrix[j][i] > 0){
lambdaMatrix[j][i] = log(alphaMatrix[j][i]);
}
else{
lambdaMatrix[j][i] = -10.0;
}
}
}
return 0;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "kMeans");
exit(1);
}
}
/**************************************************************************************************/
//based on r function .medoid
//results is length numOTUs and holds the distances from x of the sample in d with the min sum of distances to all other samples.
//Basically the "best" medoid.
//returns the sum of the distances squared
double CommunityTypeFinder::rMedoid(vector< vector<double> > x, vector< vector<double> > d){
try {
vector<double> results; results.resize(numOTUs, 0.0);
double minSumDist = MOTHURMAX;
int minGroup = -1;
for (int i = 0; i < d.size(); i++) {
if (m->getControl_pressed()) { break; }
double thisSum = 0.0;
for (int j = 0; j < d[i].size(); j++) { thisSum += d[i][j]; }
if (thisSum < minSumDist) {
minSumDist = thisSum;
minGroup = i;
}
}
if (minGroup != -1) {
for (int i = 0; i < numOTUs; i++) { results[i] = x[minGroup][i]; } //save minGroups relativeAbundance for each OTU
}else { m->mothurOut("[ERROR]: unable to find rMedoid group.\n"); m->setControl_pressed(true); }
double allMeanDist = 0.0;
for (int i = 0; i < x.size(); i++) { //numSamples
for (int j = 0; j < x[i].size(); j++) { //numOTus
if (m->getControl_pressed()) { break; }
allMeanDist += ((x[i][j]-results[j])*(x[i][j]-results[j])); //(otuX sampleY - otuX bestMedoid)^2
}
}
return allMeanDist;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "rMedoid");
exit(1);
}
}
/**************************************************************************************************/
/*To assess the optimal number of clusters our dataset was most robustly partitioned into, we used the Calinski-Harabasz (CH) Index that has shown good performance in recovering the number of clusters. It is defined as:
CHk=Bk/(k−1)/Wk/(n−k)
where Bk is the between-cluster sum of squares (i.e. the squared distances between all points i and j, for which i and j are not in the same cluster) and Wk is the within-clusters sum of squares (i.e. the squared distances between all points i and j, for which i and j are in the same cluster). This measure implements the idea that the clustering is more robust when between-cluster distances are substantially larger than within-cluster distances. Consequently, we chose the number of clusters k such that CHk was maximal.*/
double CommunityTypeFinder::calcCHIndex(vector< vector< double> > dists){
try {
double CH = 0.0;
if (numPartitions < 2) { return CH; }
map<int, int> clusterMap; //map sample to partition
for (int j = 0; j < numSamples; j++) {
double maxValue = -MOTHURMAX;
for (int i = 0; i < numPartitions; i++) {
if (m->getControl_pressed()) { return 0.0; }
if (zMatrix[i][j] > maxValue) { //for kmeans zmatrix contains values for each sample in each partition. partition with highest value for that sample is the partition where the sample should be
clusterMap[j] = i;
maxValue = zMatrix[i][j];
}
}
}
//make countMatrix a relabund
vector<vector<double> > relativeAbundance(numSamples); //[numSamples][numOTUs]
//get relative abundance
for(int i=0;i<numSamples;i++){
if (m->getControl_pressed()) { return 0; }
int groupTotal = 0;
relativeAbundance[i].assign(numOTUs, 0.0);
for(int j=0;j<numOTUs;j++){
groupTotal += countMatrix[i][j];
}
for(int j=0;j<numOTUs;j++){
relativeAbundance[i][j] = countMatrix[i][j] / (double)groupTotal;
}
}
//find centers
vector<vector<double> > centers = calcCenters(dists, clusterMap, relativeAbundance);
if (m->getControl_pressed()) { return 0.0; }
double allMeanDist = rMedoid(relativeAbundance, dists);
if (m->getDebug()) { m->mothurOut("[DEBUG]: allMeandDist = " + toString(allMeanDist) + "\n"); }
for (int i = 0; i < relativeAbundance.size(); i++) {//numSamples
for (int j = 0; j < relativeAbundance[i].size(); j++) { //numOtus
if (m->getControl_pressed()) { return 0; }
//x <- (x - centers[cl, ])^2
relativeAbundance[i][j] = ((relativeAbundance[i][j] - centers[clusterMap[i]][j])*(relativeAbundance[i][j] - centers[clusterMap[i]][j]));
}
}
double wgss = 0.0;
for (int j = 0; j < numOTUs; j++) {
for(int i=0;i<numSamples;i++){
if (m->getControl_pressed()) { return 0.0; }
wgss += relativeAbundance[i][j];
}
}
double bgss = allMeanDist - wgss;
CH = (bgss / (double)(numPartitions - 1)) / (wgss / (double) (numSamples - numPartitions));
return CH;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "calcCHIndex");
exit(1);
}
}
/**************************************************************************************************/
vector<vector<double> > CommunityTypeFinder::calcCenters(vector<vector<double> >& dists, map<int, int> clusterMap, vector<vector<double> >& relativeAbundance) { //[numsamples][numsamples]
try {
//for each partition
//choose sample with smallest sum of squared dists
vector<vector<double> > centers; centers.resize(numPartitions);
vector<double> sums; sums.resize(numSamples, 0.0);
map<int, vector<int> > partition2Samples; //maps partitions to samples in the partition
map<int, vector<int> >::iterator it;
for (int i = 0; i < numSamples; i++) {
int partitionI = clusterMap[i];
//add this sample to list of samples in this partition for access later
it = partition2Samples.find(partitionI);
if (it == partition2Samples.end()) {
vector<int> temp; temp.push_back(i);
partition2Samples[partitionI] = temp;
}else { partition2Samples[partitionI].push_back(i); }
for (int j = 0; j < numSamples; j++) {
int partitionJ = clusterMap[j];
if (partitionI == partitionJ) { //if you are a distance between samples in the same cluster
sums[i] += dists[i][j];
sums[j] += dists[i][j];
}else{}//we dont' care about distance between clusters
}
}
vector<int> medoidsVector; medoidsVector.resize(numPartitions, -1);
for (it = partition2Samples.begin(); it != partition2Samples.end(); it++) { //for each partition look for sample with smallest squared
//sum dist to all other samples in cluster
vector<int> members = it->second;
double minSumDist = MOTHURMAX;
for (int i = 0; i < members.size(); i++) {
if (m->getControl_pressed()) { return centers; }
if (sums[members[i]] < minSumDist) {
minSumDist = sums[members[i]];
medoidsVector[it->first] = members[i];
}
}
}
set<int> medoids;
for (int i = 0; i < medoidsVector.size(); i++) {
medoids.insert(medoidsVector[i]);
}
int countPartitions = 0;
for (set<int>::iterator it = medoids.begin(); it != medoids.end(); it++) {
for (int j = 0; j < numOTUs; j++) {
centers[countPartitions].push_back(relativeAbundance[*it][j]); //save the relative abundance of the medoid for this partition for this OTU
}
countPartitions++;
}
return centers;
}
catch(exception& e){
m->errorOut(e, "CommunityTypeFinder", "calcCenters");
exit(1);
}
}
/**************************************************************************************************/
//The silhouette width S(i)of individual data points i is calculated using the following formula:
/*
s(i) = b(i) - a(i)
-----------
max(b(i),a(i))
where a(i) is the average dissimilarity (or distance) of sample i to all other samples in the same cluster, while b(i) is the average dissimilarity (or distance) to all objects in the closest other cluster.
The formula implies -1 =< S(i) =< 1 . A sample which is much closer to its own cluster than to any other cluster has a high S(i) value, while S(i) close to 0 implies that the given sample lies somewhere between two clusters. Large negative S(i) values indicate that the sample was assigned to the wrong cluster.
*/
//based on silouette.r which calls sildist.c written by Francois Romain
vector<double> CommunityTypeFinder::calcSilhouettes(vector<vector<double> > dists) {
try {
vector<double> silhouettes; silhouettes.resize(numSamples, 0.0);
if (numPartitions < 2) { return silhouettes; }
map<int, int> clusterMap; //map sample to partition
for (int j = 0; j < numSamples; j++) {
double maxValue = 0.0;
for (int i = 0; i < numPartitions; i++) {
if (m->getControl_pressed()) { return silhouettes; }
if (zMatrix[i][j] > maxValue) { //for kmeans zmatrix contains values for each sample in each partition. partition with highest value for that sample is the partition where the sample should be
clusterMap[j] = i;
maxValue = zMatrix[i][j];
}
}
}
//count number of samples in each partition
vector<int> counts; counts.resize(numPartitions, 0);
vector<double> DiC; DiC.resize((numPartitions*numSamples), 0.0);
bool computeSi = true;
for (int i = 0; i < numSamples; i++) {
int partitionI = clusterMap[i];
counts[partitionI]++;
for (int j = i+1; j < numSamples; j++) {
if (m->getControl_pressed()) { return silhouettes; }
int partitionJ = clusterMap[j];
DiC[numPartitions*i+partitionJ] += dists[i][j];
DiC[numPartitions*j+partitionI] += dists[i][j];
}
}
vector<int> neighbor; neighbor.resize(numSamples, -1);
for (int i = 0; i < numSamples; i++) {
if (m->getControl_pressed()) { return silhouettes; }
int ki = numPartitions*i;
int partitionI = clusterMap[i];
computeSi = true;
for (int j = 0; j < numPartitions; j++) {
if (j == partitionI) {
if (counts[j] == 1) { //only one sample in cluster
computeSi = false;
}else { DiC[ki+j] /= (counts[j]-1); }
}else{
DiC[ki+j] /= counts[j];
}
}
double ai = DiC[ki+partitionI];
double bi = 0.0;
if (partitionI == 0) { bi = DiC[ki+1]; neighbor[i] = 2; }
else { bi = DiC[ki]; neighbor[i] = 1; }
for (int j = 1; j < numPartitions; j++) {
if (j != partitionI) {
if (bi > DiC[ki+j]) {
bi = DiC[ki + j];
neighbor[i] = j+1;
}
}
}
silhouettes[i] = 0.0;
if (computeSi && !util.isEqual(bi, ai)) {
silhouettes[i] = (bi-ai) / (max(ai, bi));
}
}
return silhouettes;
}
catch(exception& e) {
m->errorOut(e, "CommunityTypeFinder", "calcSilhouettes");
exit(1);
}
}
/**************************************************************************************************/
|