443757e6a04336d7217fca4abe0e3774613323ea
chmalee
  Fri May 22 16:22:33 2020 -0700
Adding a comment to a function after code review, refs #25585

diff --git src/hg/hgTracks/vcfTrack.c src/hg/hgTracks/vcfTrack.c
index 799787f..a3251b9 100644
--- src/hg/hgTracks/vcfTrack.c
+++ src/hg/hgTracks/vcfTrack.c
@@ -1814,30 +1814,32 @@
 int i;
 struct vcfRecord *rec = vcff->records;
 int ix = 0; // index into ret
 for (i = 0; i < slCount(hapArray); i++)
     {
     struct hapCluster *hc = hapArray[i];
     struct vcfGenotype *gt = &(rec->genotypes[hc->gtHapIx >> 1]);
     if (!doChild && !sameString(gt->id, sample))
         ret[ix++] = i;
     else if (doChild && sameString(gt->id, sample))
         ret[ix++] = i;
     }
 }
 
 static struct hapDistanceMatrix *fillOutDistanceMatrix(struct hapCluster **hapArray, struct vcfFile *vcff, char *sample, struct cwaExtraData *helper, int gtCount)
+/* Allocates and fill out a struct hapDistanceMatrix, one row per child allele, and a
+ * hapDistanceMatrixCell per parent allele */
 {
 short parGtCount = (gtCount - 1) * 2;
 int i,j;
 struct vcfRecord *rec = vcff->records;
 struct hapDistanceMatrix *matrix = NULL;
 short childHapArrayIndices[2];
 short parentHapArrayIndices[parGtCount];
 assignHapArrayIx(childHapArrayIndices, hapArray, vcff, sample, TRUE);
 assignHapArrayIx(parentHapArrayIndices, hapArray, vcff, sample, FALSE);
 for (i = 0; i < 2; i++)
     {
     struct hapDistanceMatrix *row = needMem(sizeof(struct hapDistanceMatrix));
     struct hapCluster *hcChild = hapArray[childHapArrayIndices[i]];
     struct vcfGenotype *gt = &(rec->genotypes[hcChild->gtHapIx >> 1]);
     row->row = NULL;