# HG changeset patch
# User Markus Mützel <markus.muetzel@gmx.de>
# Date 1661354134 -7200
# Node ID 863730dd0f839b1778723fa4fb969b4fe6776df0
# Parent  4c38cf0ce06cf4a37a5eb37ec6f3235d5a62defd
nextpow2: Fix for input between 0.5 and 1 (bug #62947).

* scripts/general/nextpow2.m: Switch to a naïve implementation using log2 with
a single output argument and ceil.

diff -r 4c38cf0ce06c -r 863730dd0f83 scripts/general/nextpow2.m
--- a/scripts/general/nextpow2.m	Tue Aug 23 19:44:16 2022 +0200
+++ b/scripts/general/nextpow2.m	Wed Aug 24 17:15:34 2022 +0200
@@ -49,10 +49,8 @@
     error ("nextpow2: X must be numeric");
   endif
 
-  [f, n] = log2 (abs (x));
-  idx = (n == 0);   # Find any failures of log2 function (n == 0)
-  n(idx) = f(idx);  # and copy over value.
-  n(f == 0.5)--;
+  n = ceil (log2 (abs (x)));
+  n(x == 0) = 0;  # special case
 
 endfunction
 
@@ -64,6 +62,8 @@
 %!assert (nextpow2 (-17), 5)
 %!assert (nextpow2 (-31), 5)
 %!assert (nextpow2 (1:17), [0 1 2 2 3 3 3 3 4 4 4 4 4 4 4 4 5])
+%!assert (nextpow2 (0.5), -1)
+%!assert (nextpow2 (0.6), 0)
 ## Special cases
 %!assert (nextpow2 (0), 0)
 %!assert (nextpow2 (1), 0)