help and error string corrected in hist.m

[Francesco Potorti`]

I now see that Mercurial does not like latin-1 in .hgrc.  So I put a
dummy string in place of my family name and changed it to the real
surname in the following changeset.  But beware: maybe Mercurial does
not like it for the same reason, so if you get strange behaviour while
applying this, you should change my surname.

# HG changeset patch
# User Francesco Potortì <pot at gnu.org>
# Date 1222347416 -7200
# Node ID 6ec7b2c6fc61e9654a6d3daa8c37396b51be0a8e
# Parent  060b397aa568620b450f92055c05b0d647a8ba31
help and error string corrected in hist.m

diff -r 060b397aa568 -r 6ec7b2c6fc61 scripts/ChangeLog
--- a/scripts/ChangeLog	Wed Sep 24 13:24:17 2008 +0200
+++ b/scripts/ChangeLog	Thu Sep 25 14:56:56 2008 +0200
@@ -1,3 +1,8 @@
+2008-09-25  Francesco Potortì  <pot at gnu.org>
+
+	* plot/hist.m: Doc string now mentions matrix input argument.
+	Correct error message.
+
 2008-09-23  Francesco Potorti`  <Potorti at isti.cnr.it>
 
 	* plot/pcolor.m: Improve doc string.
diff -r 060b397aa568 -r 6ec7b2c6fc61 scripts/plot/hist.m
--- a/scripts/plot/hist.m	Wed Sep 24 13:24:17 2008 +0200
+++ b/scripts/plot/hist.m	Thu Sep 25 14:56:56 2008 +0200
@@ -23,7 +23,8 @@
 ##
 ## With one vector input argument, plot a histogram of the values with
 ## 10 bins.  The range of the histogram bins is determined by the range
-## of the data.
+## of the data.  With one matrix input argument, plot a hystogram where
+## each bin contains a bar per input column.
 ##
 ## Given a second scalar argument, use that as the number of bins.
 ##
@@ -59,7 +60,7 @@
     max_val = max (y(:));
     min_val = min (y(:));
   else
-    error ("hist: first argument must be a vector");
+    error ("hist: first argument must be real valued");
   endif
 
   iarg = 1;