[Maxima-commits] CVS: maxima/doc/info nset.texi,1.18,1.19

[Robert D. <rob...@us...>]

Update of /cvsroot/maxima/maxima/doc/info
In directory sc8-pr-cvs16:/tmp/cvs-serv1385/doc/info

Modified Files:
	nset.texi 
Log Message:
Description of function random_permutation.

Index: nset.texi
===================================================================
RCS file: /cvsroot/maxima/maxima/doc/info/nset.texi,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -d -r1.18 -r1.19
--- nset.texi	22 Mar 2007 14:29:18 -0000	1.18
+++ nset.texi	18 Apr 2007 16:26:34 -0000	1.19
@@ -1633,6 +1633,8 @@
 
 @code{permutations} complains if @var{a} is not a literal list or set.
 
+See also @code{random_permutation}.
+
 Examples:
 
 @c ===beg===
@@ -1690,6 +1692,36 @@
 
 @end deffn
 
+@deffn {Function} random_permutation (@var{a})
+
+Returns a random permutation of the set or list @var{a},
+as constructed by the Knuth shuffle algorithm.
+
+The return value is a new list, which is distinct
+from the argument even if all elements happen to be the same.
+However, the elements of the argument are not copied.
+
+Examples:
+
+@c ===beg===
+@c random_permutation ([a, b, c, 1, 2, 3]);
+@c random_permutation ([a, b, c, 1, 2, 3]);
+@c random_permutation ({x + 1, y + 2, z + 3});
+@c random_permutation ({x + 1, y + 2, z + 3});
+@c ===end===
+@example
+(%i1) random_permutation ([a, b, c, 1, 2, 3]);
+(%o1)                  [c, 1, 2, 3, a, b]
+(%i2) random_permutation ([a, b, c, 1, 2, 3]);
+(%o2)                  [b, 3, 1, c, a, 2]
+(%i3) random_permutation (@{x + 1, y + 2, z + 3@});
+(%o3)                 [y + 2, z + 3, x + 1]
+(%i4) random_permutation (@{x + 1, y + 2, z + 3@});
+(%o4)                 [x + 1, y + 2, z + 3]
+@end example
+
+@end deffn
+
 @anchor{rreduce}
 @deffn {Function} rreduce (@var{F}, @var{s})
 @deffnx {Function} rreduce (@var{F}, @var{s}, @var{s_@{n + 1@}})