octave: scripts/general/nextpow2.m annotate

annotate scripts/general/nextpow2.m @ 25236:69b21b8a0e9f

nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). * nextpow2.m: Change docstring to define the output variable N. Check for failure of 2-input form of log2 function by looking for an exponent of 0. If found, copy over the value that log2 was not able to process (e.g., Inf or NaN). Add BIST tests for special cases. Add fail pattern to %!error test.

author	Rik <rik@octave.org>
date	Thu, 12 Apr 2018 14:34:10 -0700
parents	6652d3823428
children	996d78102a71

rev	line source
25054 6652d3823428 maint: Update copyright dates in all source files. John W. Eaton <jwe@octave.org> parents: 24534 diff changeset	1 ## Copyright (C) 1995-2018 Kurt Hornik
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	2 ##
3922 38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	3 ## This file is part of Octave.
38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	4 ##
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	5 ## Octave is free software: you can redistribute it and/or modify it
3922 38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	6 ## under the terms of the GNU General Public License as published by
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	7 ## the Free Software Foundation, either version 3 of the License, or
22755 3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	8 ## (at your option) any later version.
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	9 ##
3922 38c61cbf086c [project @ 2002-05-01 06:48:35 by jwe] jwe parents: 3426 diff changeset	10 ## Octave is distributed in the hope that it will be useful, but
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
22755 3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	13 ## GNU General Public License for more details.
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	14 ##
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	15 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6046 diff changeset	16 ## along with Octave; see the file COPYING. If not, see
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	17 ## <https://www.gnu.org/licenses/>.
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	18
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	19 ## -- texinfo --
25236 69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	20 ## @deftypefn {} {@var{n} =} nextpow2 (@var{x})
20158 7503499a252b doc: Update docstrings to have one sentence summary as first line. Rik <rik@octave.org> parents: 19788 diff changeset	21 ## Compute the exponent for the smallest power of two larger than the input.
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	22 ##
20158 7503499a252b doc: Update docstrings to have one sentence summary as first line. Rik <rik@octave.org> parents: 19788 diff changeset	23 ## For each element in the input array @var{x}, return the first integer
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	24 ## @var{n} such that
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	25 ## @tex
9167 1231b1762a9a Simplify TeXinfo and eliminate use of @iftex in arith.txi Rik <rdrider0-list@yahoo.com> parents: 9141 diff changeset	26 ## $2^n \ge \|x\|$.
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	27 ## @end tex
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 7017 diff changeset	28 ## @ifnottex
10793 be55736a0783 Grammarcheck the documentation from m-files. Rik <octave@nomad.inbox5.com> parents: 9167 diff changeset	29 ## 2^n @geq{} abs (x).
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 7017 diff changeset	30 ## @end ifnottex
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	31 ##
9141 c1fff751b5a8 Update section 17.1 (Utility Functions) of arith.txi Rik <rdrider0-list@yahoo.com> parents: 8920 diff changeset	32 ## @seealso{pow2, log2}
3321 6923abb04e16 [project @ 1999-10-26 18:15:30 by jwe] jwe parents: 2816 diff changeset	33 ## @end deftypefn
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	34
5428 2a16423e4aa0 [project @ 2005-08-23 18:38:27 by jwe] jwe parents: 5307 diff changeset	35 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	36 ## Created: 7 October 1994
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	37 ## Adapted-By: jwe
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	38
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	39 function n = nextpow2 (x)
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	40
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	41 if (nargin != 1)
6046 34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe] jwe parents: 5642 diff changeset	42 print_usage ();
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	43 endif
1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	44
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	45 if (! isnumeric (x))
511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	46 error ("nextpow2: X must be numeric");
2816 ad4bf2a82b4f [project @ 1997-03-15 21:08:25 by jwe] jwe parents: 2539 diff changeset	47 endif
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	48
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	49 [f, n] = log2 (abs (x));
25236 69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	50 idx = (n == 0); # Find any failures of log2 function (n == 0)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	51 n(idx) = f(idx); # and copy over value.
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	52 n(f == 0.5)--;
3426 f8dde1807dee [project @ 2000-01-13 08:40:00 by jwe] jwe parents: 3407 diff changeset	53
2539 1dca28c213f0 [project @ 1996-11-19 23:54:48 by jwe] jwe parents: diff changeset	54 endfunction
12795 9e7ebbaf69ff codesprint: new tests for files in scripts/general directory John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	55
9e7ebbaf69ff codesprint: new tests for files in scripts/general directory John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	56
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	57 %!assert (nextpow2 (16), 4)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	58 %!assert (nextpow2 (17), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	59 %!assert (nextpow2 (31), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	60 %!assert (nextpow2 (-16), 4)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	61 %!assert (nextpow2 (-17), 5)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	62 %!assert (nextpow2 (-31), 5)
19788 511b3ae4872b nextpow2: compute for each element of input instead of its length (bug #44291) Carnë Draug <carandraug@octave.org> parents: 19697 diff changeset	63 %!assert (nextpow2 (1:17), [0 1 2 2 3 3 3 3 4 4 4 4 4 4 4 4 5])
25236 69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	64 ## Special cases
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	65 %!assert (nextpow2 (0), 0)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	66 %!assert (nextpow2 (1), 0)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	67 %!assert (nextpow2 (Inf), Inf)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	68 %!assert (nextpow2 (-Inf), Inf)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	69 %!assert (nextpow2 (NaN), NaN)
69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	70 %!assert (nextpow2 ([1, Inf, 3, -Inf, 9, NaN]), [0, Inf, 2, Inf, 4, NaN])
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	71
25236 69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	72 ## Test input validation
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	73 %!error nexpow2 ()
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	74 %!error nexpow2 (1, 2)
25236 69b21b8a0e9f nextpow2.m: Compute value correctly for Inf or NaN inputs (bug #53463). Rik <rik@octave.org> parents: 25054 diff changeset	75 %!error <X must be numeric> nextpow2 ("t")

Mercurial > octave

annotate scripts/general/nextpow2.m @ 25236:69b21b8a0e9f