9a51fe6723423851ee77535b465399a52e244084
kent
  Mon Jan 11 18:16:04 2021 -0800
Improving usage statement per code review #26745

diff --git src/utils/matrixToBarChartBed/matrixToBarChartBed.c src/utils/matrixToBarChartBed/matrixToBarChartBed.c
index 32a0b73..dcc0b65 100644
--- src/utils/matrixToBarChartBed/matrixToBarChartBed.c
+++ src/utils/matrixToBarChartBed/matrixToBarChartBed.c
@@ -9,30 +9,33 @@
 #include "sqlNum.h"
 
 int clBedIx = 4;
 
 void usage()
 /* Explain usage and exit. */
 {
 errAbort(
   "matrixToBarChartBed - Attach a labeled expression matrix to a bed file joining\n"
   "on the matrix's first column and the bed's name column.\n"
   "usage:\n"
   "   matrixToBarChartBed matrix.tsv mapping.bed barChartOutput.bed\n"
   "where\n"
   "   matrix is tab-separated values with the first row and column used as labels\n"
   "   mapping.bed maps a row of the matrix using the bed's name field and matrix's 1st field\n"
+  "        The mapping.bed file is expected to have a 'name2' field as it's last column\n"
+  "        and otherwise be at least bed 6.   Only the first 6 fields plus the name2 field are\n"
+  "        used.  Often this file will be made with gencodeVersionForGenes\n"
   "options:\n"
   "   -bedIx=N - use the N'th column of the mapping.bed as the id column. Default %d\n"
   "   -trackDb=stanza.txt -output a trackDb stanza for this as a track\n"
   "   -stats=stats.tsv - stats file from matrixClusterColumns, makes coloring in trackDb better\n"
   , clBedIx);
 }
 
 /* Command line validation table. */
 static struct optionSpec options[] = {
    {"bedIx", OPTION_INT},
    {"trackDb", OPTION_STRING},
    {"stats", OPTION_STRING},
    {NULL, 0},
 };