Mercurial > hg > octave-lojdl
changeset 10892:20ce631f0f12
Add new randi function for random integers.
author | Rik <octave@nomad.inbox5.com> |
---|---|
date | Sun, 15 Aug 2010 13:50:41 -0700 |
parents | ff94219746bd |
children | 61a5ba82cfbb |
files | doc/ChangeLog doc/interpreter/matrix.txi scripts/ChangeLog scripts/general/module.mk scripts/general/randi.m scripts/miscellaneous/unimplemented.m |
diffstat | 6 files changed, 150 insertions(+), 1 deletions(-) [+] |
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--- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,7 @@ +2010-08-15 Rik <octave@nomad.inbox5.com> + + * interpreter/matrx.txi: Add documentation for randi function. + 2010-08-13 Rik <octave@nomad.inbox5.com> * interpreter/Makefile.am: Update @EXAMPLEFILE dependencies.
--- a/doc/interpreter/matrix.txi +++ b/doc/interpreter/matrix.txi @@ -179,6 +179,8 @@ @DOCSTRING(rand) +@DOCSTRING(randi) + @DOCSTRING(randn) @DOCSTRING(rande)
--- a/scripts/ChangeLog +++ b/scripts/ChangeLog @@ -1,3 +1,9 @@ +2010-08-15 Rik <octave@nomad.inbox5.com> + + * general/randi.m: Add new script for random integers. + * general/module.mk: Add randi to build file list. + * miscellaneous/unimplemented.m: Remove randi from unimplemented list. + 2010-08-15 Rik <octave@nomad.inbox5.com> * image/imwrite.m: Allow writing of 1-bit (B&W) images.
--- a/scripts/general/module.mk +++ b/scripts/general/module.mk @@ -62,6 +62,7 @@ general/quadgk.m \ general/quadl.m \ general/quadv.m \ + general/randi.m \ general/rat.m \ general/repmat.m \ general/rot90.m \
new file mode 100644 --- /dev/null +++ b/scripts/general/randi.m @@ -0,0 +1,137 @@ +## Copyright (C) 2010 Rik Wehbring +## +## This file is part of Octave. +## +## Octave 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 3 of the License, or (at +## your option) any later version. +## +## Octave 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 Octave; see the file COPYING. If not, see +## <http://www.gnu.org/licenses/>. + +## -*- texinfo -*- +## @deftypefn {Function File} {} randi (@var{imax}) +## @deftypefnx {Function File} {} randi (@var{imax}, @var{n}) +## @deftypefnx {Function File} {} randi (@var{imax}, @var{m}, @var{n}, @dots{}) +## @deftypefnx {Function File} {} randi ([@var{imin}, @var{imax}], @dots{}) +## @deftypefnx {Function File} {} randi (@dots{}, "@var{class}") +## Return random integers in the range 1:@var{imax}. +## +## Additional arguments determine the shape of the return matrix. When no +## arguments are specified a single random integer is returned. If one +## argument @var{n} is specified then a square matrix @w{(@var{n} x @var{n})} is +## returned. Two or more arguments will return a multi-dimensional +## matrix @w{(@var{m} x @var{n} x @dots{})}. +## +## The integer range may optionally be described by a two element matrix +## with a lower and upper bound in which case the returned integers will be +## on the interval @w{[@var{imin}, @var{imax}]}. +## +## The optional argument "@var{class}" will return a matrix of the requested +## type. The default is "double". +## +## The following example returns 150 integers in the range 1-10. +## +## @example +## ri = randi (10, 150, 1); +## @end example +## +## Implementation Note: @code{randi} relies internally on @code{rand} which +## uses class "double" to represent numbers. This limits the maximum +## integer (@var{imax}) and range (@var{imax} - @var{imin}) to the value +## returned by the @code{bitmax} function. For IEEE floating point numbers +## this value is @w{@code{2^53 - 1}}. +## +## @seealso{rand} +## @end deftypefn + +## Author: Rik Wehbring + +function ri = randi (bounds, varargin) + + if (nargin < 1) + print_usage(); + endif + + if (! (isnumeric (bounds) && isreal (bounds))) + error ("randi: IMIN and IMAX must be real numeric bounds"); + endif + + if (isscalar (bounds)) + imin = 1; + imax = fix (bounds); + if (imax < 1) + error ("randi: require IMAX >= 1"); + endif + else + imin = fix (bounds(1)); + imax = fix (bounds(2)); + if (imax < imin) + error ("randi: require IMIN <= IMAX"); + endif + endif + + if (nargin > 1 && ischar (varargin{end})) + rclass = varargin{end}; + varargin(end) = []; + else + rclass = "double"; + endif + + ## FIXME: No check for class "single" + if (strfind (rclass, "int")) + if (imax > intmax (rclass)) + error ("randi: require IMAX < intmax (CLASS)"); + endif + endif + ## Limit set by use of class double in rand() + if (imax > bitmax) + error ("randi: maximum integer IMAX must be smaller than bitmax ()"); + endif + if ((imax - imin) > bitmax) + error ("randi: maximum integer range must be smaller than bitmax ()"); + endif + + + ri = imin + floor ( (imax-imin+1)*rand (varargin{:}) ); + + if (! strcmp (rclass, "double")) + ri = cast (ri, rclass); + endif + +endfunction + +%!test +%! ri = randi (10, 1000, 1); +%! assert(isequal(ri, fix (ri))); +%! assert(min(ri) == 1); +%! assert(max(ri) == 10); +%! assert(rows(ri) == 1000); +%! assert(columns(ri) == 1); +%! assert(strcmp (class (ri), "double")); +%!test +%! ri = randi ([-5, 10], 1000, 1, "int8"); +%! assert(isequal(ri, fix (ri))); +%! assert(min(ri) == -5); +%! assert(max(ri) == 10); +%! assert(strcmp (class (ri), "int8")); +%! +%!assert(size (randi(10, 3,1,2)) == [3, 1, 2]) + +%% Test input validation +%!error(randi()) +%!error(randi("test")) +%!error(randi(10+2i)) +%!error(randi(0)) +%!error(randi([10, 1])) +%!error(randi(256, "uint8")) +%!error(randi(bitmax() + 1)) +%!error(randi([-1, bitmax()])) +