diff scripts/general/nextpow2.m @ 2539:1dca28c213f0

[project @ 1996-11-19 23:54:48 by jwe]
author jwe
date Tue, 19 Nov 1996 23:55:06 +0000
parents
children ad4bf2a82b4f
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/general/nextpow2.m	Tue Nov 19 23:55:06 1996 +0000
@@ -0,0 +1,45 @@
+## Copyright (C) 1995, 1996 Kurt Hornik
+## 
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2, or (at your option)
+## any later version.
+## 
+## This program is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details. 
+## 
+## You should have received a copy of the GNU General Public License
+## along with this file.  If not, write to the Free Software Foundation,
+## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+## usage:  nextpow2 (x)
+##
+## If x is a scalar, returns the first integer n such that
+## 2^n >= abs (x). 
+##
+## If x is a vector, return nextpow2 (length (x)). 
+
+## Author: KH <Kurt.Hornik@ci.tuwien.ac.at>
+## Created: 7 October 1994
+## Adapted-By: jwe
+
+function n = nextpow2 (x)
+  
+  if (nargin != 1)
+    usage ("nextpow2 (x)");
+  endif
+
+  if (is_vector (x))
+    x = length (x);
+  elseif (! is_scalar (x))
+    error ("nextpow2: x must be a scalar or a vector");
+  endif
+  
+  [f, n] = log2 (abs (x));
+  if (f == 0.5)
+    n = n - 1;
+  endif
+  
+endfunction