Index: /trunk/Ohana/src/opihi/cmd.data/help/histogram
===================================================================
--- /trunk/Ohana/src/opihi/cmd.data/help/histogram	(revision 28336)
+++ /trunk/Ohana/src/opihi/cmd.data/help/histogram	(revision 28337)
@@ -1,8 +1,19 @@
 
-   histogram <buffer> <x> <y> [-region sx sy nx ny] [-range min max]
+   histogram <invec> <outvec> <start> <end> [<delta>] [-range <dx_outvec>]
 
-   calculate a histogram of the image pixel values in the given
-   buffer, optionally constrained to the given region, with optional
-   max and min values.  the results are placed in the vectors x and y,
-   which contain the pixel values and the number of occurences.
+   calculate a histogram of the <invec> values and store the
+   occurrences count in the <outvec> buffer. Optionally constrained to
+   the given <start>-<end> region with <delta> step value (default
+   step is 1). The optional '-range <dx_outvec>' parameter allows storing
+   the range <start>-<end> values with <delta> increment
 
+   Sample code usage:
+   
+   # create a vector ('x') containing arbitrary values  [0.:1.] range
+   create y 0 100 1; set x = sin(y)
+
+   # build histogram from x from 0. to 1. with 0.1 delta step
+   histogram x xhist 0. 1. .1 -range dx
+
+   # plot corresponding histogram
+   limits dx xhist; clear; box; plot dx xhist -x 1