Mercurial > octave-antonio
view scripts/general/accumarray.m @ 20158:7503499a252b stable
doc: Update docstrings to have one sentence summary as first line.
Update scripts in audio, elfun, general, geometry, and image directories.
* scripts/audio/@audioplayer/__get_properties__.m,
scripts/audio/@audioplayer/audioplayer.m, scripts/audio/@audioplayer/get.m,
scripts/audio/@audioplayer/isplaying.m, scripts/audio/@audioplayer/play.m,
scripts/audio/@audioplayer/playblocking.m, scripts/audio/@audioplayer/set.m,
scripts/audio/@audioplayer/subsasgn.m, scripts/audio/@audioplayer/subsref.m,
scripts/audio/@audiorecorder/audiorecorder.m,
scripts/audio/@audiorecorder/get.m,
scripts/audio/@audiorecorder/getaudiodata.m,
scripts/audio/@audiorecorder/getplayer.m,
scripts/audio/@audiorecorder/isrecording.m,
scripts/audio/@audiorecorder/play.m, scripts/audio/@audiorecorder/record.m,
scripts/audio/@audiorecorder/recordblocking.m,
scripts/audio/@audiorecorder/set.m, scripts/audio/@audiorecorder/stop.m,
scripts/audio/@audiorecorder/subsasgn.m,
scripts/audio/@audiorecorder/subsref.m, scripts/audio/lin2mu.m,
scripts/audio/mu2lin.m, scripts/audio/record.m, scripts/audio/sound.m,
scripts/audio/soundsc.m, scripts/audio/wavread.m, scripts/audio/wavwrite.m,
scripts/elfun/cosd.m, scripts/elfun/sind.m, scripts/elfun/tand.m,
scripts/general/accumarray.m, scripts/general/accumdim.m,
scripts/general/bitcmp.m, scripts/general/bitget.m, scripts/general/bitset.m,
scripts/general/blkdiag.m, scripts/general/cart2pol.m,
scripts/general/cart2sph.m, scripts/general/cell2mat.m,
scripts/general/celldisp.m, scripts/general/chop.m,
scripts/general/circshift.m, scripts/general/common_size.m,
scripts/general/cplxpair.m, scripts/general/cumtrapz.m,
scripts/general/dblquad.m, scripts/general/deal.m, scripts/general/del2.m,
scripts/general/display.m, scripts/general/divergence.m,
scripts/general/fieldnames.m, scripts/general/flip.m,
scripts/general/flipdim.m, scripts/general/fliplr.m, scripts/general/flipud.m,
scripts/general/gradient.m, scripts/general/interp3.m,
scripts/general/interpft.m, scripts/general/interpn.m,
scripts/general/loadobj.m, scripts/general/logspace.m,
scripts/general/methods.m, scripts/general/nargchk.m,
scripts/general/narginchk.m, scripts/general/nargoutchk.m,
scripts/general/nextpow2.m, scripts/general/nthargout.m,
scripts/general/num2str.m, scripts/general/pol2cart.m,
scripts/general/polyarea.m, scripts/general/postpad.m,
scripts/general/prepad.m, scripts/general/profile.m, scripts/general/quadgk.m,
scripts/general/quadl.m, scripts/general/quadv.m, scripts/general/randi.m,
scripts/general/rat.m, scripts/general/repmat.m, scripts/general/rot90.m,
scripts/general/rotdim.m, scripts/general/saveobj.m, scripts/general/shift.m,
scripts/general/shiftdim.m, scripts/general/sortrows.m,
scripts/general/sph2cart.m, scripts/general/structfun.m,
scripts/general/subsindex.m, scripts/general/trapz.m,
scripts/general/triplequad.m, scripts/geometry/delaunayn.m,
scripts/geometry/dsearch.m, scripts/geometry/dsearchn.m,
scripts/geometry/griddata.m, scripts/geometry/griddata3.m,
scripts/geometry/griddatan.m, scripts/geometry/inpolygon.m,
scripts/geometry/rectint.m, scripts/geometry/tsearchn.m,
scripts/geometry/voronoi.m, scripts/geometry/voronoin.m,
scripts/help/__unimplemented__.m, scripts/help/doc.m,
scripts/help/doc_cache_create.m, scripts/help/get_first_help_sentence.m,
scripts/help/help.m, scripts/help/lookfor.m, scripts/help/print_usage.m,
scripts/help/type.m, scripts/help/which.m, scripts/image/autumn.m,
scripts/image/bone.m, scripts/image/brighten.m, scripts/image/cmpermute.m,
scripts/image/colorcube.m, scripts/image/contrast.m, scripts/image/cool.m,
scripts/image/copper.m, scripts/image/cubehelix.m, scripts/image/flag.m,
scripts/image/gmap40.m, scripts/image/gray.m, scripts/image/gray2ind.m,
scripts/image/hot.m, scripts/image/hsv.m, scripts/image/image.m,
scripts/image/imagesc.m, scripts/image/imfinfo.m, scripts/image/imformats.m,
scripts/image/imread.m, scripts/image/imshow.m, scripts/image/imwrite.m,
scripts/image/iscolormap.m, scripts/image/jet.m, scripts/image/lines.m,
scripts/image/ntsc2rgb.m, scripts/image/ocean.m, scripts/image/pink.m,
scripts/image/prism.m, scripts/image/rainbow.m, scripts/image/rgb2ntsc.m,
scripts/image/spinmap.m, scripts/image/spring.m, scripts/image/summer.m,
scripts/image/white.m, scripts/image/winter.m:
Update docstrings to have one sentence summary as first line.
Re-structure to have line lengths <= 80 chars.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 03 May 2015 09:36:20 -0700 |
parents | e9f89866074c |
children |
line wrap: on
line source
## Copyright (C) 2007-2015 David Bateman ## Copyright (C) 2009-2010 VZLU Prague ## ## 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} {} accumarray (@var{subs}, @var{vals}, @var{sz}, @var{func}, @var{fillval}, @var{issparse}) ## @deftypefnx {Function File} {} accumarray (@var{subs}, @var{vals}, @dots{}) ## ## Create an array by accumulating the elements of a vector into the ## positions defined by their subscripts. ## ## The subscripts are defined by the rows of the matrix @var{subs} and the ## values by @var{vals}. Each row of @var{subs} corresponds to one of the ## values in @var{vals}. If @var{vals} is a scalar, it will be used for each ## of the row of @var{subs}. If @var{subs} is a cell array of vectors, all ## vectors must be of the same length, and the subscripts in the @var{k}th ## vector must correspond to the @var{k}th dimension of the result. ## ## The size of the matrix will be determined by the subscripts ## themselves. However, if @var{sz} is defined it determines the matrix ## size. The length of @var{sz} must correspond to the number of columns ## in @var{subs}. An exception is if @var{subs} has only one column, in ## which case @var{sz} may be the dimensions of a vector and the ## subscripts of @var{subs} are taken as the indices into it. ## ## The default action of @code{accumarray} is to sum the elements with ## the same subscripts. This behavior can be modified by defining the ## @var{func} function. This should be a function or function handle ## that accepts a column vector and returns a scalar. The result of the ## function should not depend on the order of the subscripts. ## ## The elements of the returned array that have no subscripts associated ## with them are set to zero. Defining @var{fillval} to some other value ## allows these values to be defined. This behavior changes, however, ## for certain values of @var{func}. If @var{func} is @code{min} ## (respectively, @code{max}) then the result will be filled with the ## minimum (respectively, maximum) integer if @var{vals} is of integral ## type, logical false (respectively, logical true) if @var{vals} is of ## logical type, zero if @var{fillval} is zero and all values are ## non-positive (respectively, non-negative), and NaN otherwise. ## ## By default @code{accumarray} returns a full matrix. If ## @var{issparse} is logically true, then a sparse matrix is returned ## instead. ## ## The following @code{accumarray} example constructs a frequency table ## that in the first column counts how many occurrences each number in ## the second column has, taken from the vector @var{x}. Note the usage ## of @code{unique} for assigning to all repeated elements of @var{x} ## the same index (@pxref{XREFunique,,unique}). ## ## @example ## @group ## @var{x} = [91, 92, 90, 92, 90, 89, 91, 89, 90, 100, 100, 100]; ## [@var{u}, ~, @var{j}] = unique (@var{x}); ## [accumarray(@var{j}', 1), @var{u}'] ## @result{} 2 89 ## 3 90 ## 2 91 ## 2 92 ## 3 100 ## @end group ## @end example ## ## Another example, where the result is a multi-dimensional 3-D array and ## the default value (zero) appears in the output: ## ## @example ## @group ## accumarray ([1, 1, 1; ## 2, 1, 2; ## 2, 3, 2; ## 2, 1, 2; ## 2, 3, 2], 101:105) ## @result{} ans(:,:,1) = [101, 0, 0; 0, 0, 0] ## @result{} ans(:,:,2) = [0, 0, 0; 206, 0, 208] ## @end group ## @end example ## ## The sparse option can be used as an alternative to the @code{sparse} ## constructor (@pxref{XREFsparse,,sparse}). Thus ## ## @example ## sparse (@var{i}, @var{j}, @var{sv}) ## @end example ## ## @noindent ## can be written with @code{accumarray} as ## ## @example ## accumarray ([@var{i}, @var{j}], @var{sv}', [], [], 0, true) ## @end example ## ## @noindent ## For repeated indices, @code{sparse} adds the corresponding value. To ## take the minimum instead, use @code{min} as an accumulator function: ## ## @example ## accumarray ([@var{i}, @var{j}], @var{sv}', [], @@min, 0, true) ## @end example ## ## The complexity of accumarray in general for the non-sparse case is ## generally O(M+N), where N is the number of subscripts and M is the ## maximum subscript (linearized in multi-dimensional case). If ## @var{func} is one of @code{@@sum} (default), @code{@@max}, ## @code{@@min} or @code{@@(x) @{x@}}, an optimized code path is used. ## Note that for general reduction function the interpreter overhead can ## play a major part and it may be more efficient to do multiple ## accumarray calls and compute the results in a vectorized manner. ## ## @seealso{accumdim, unique, sparse} ## @end deftypefn function A = accumarray (subs, vals, sz = [], func = [], fillval = [], issparse = []) if (nargin < 2 || nargin > 6) print_usage (); endif lenvals = length (vals); if (iscell (subs)) subs = cellfun (@vec, subs, "uniformoutput", false); ndims = numel (subs); if (ndims == 1) subs = subs{1}; endif lensubs = cellfun (@length, subs); if (any (lensubs != lensubs(1)) || (lenvals > 1 && lenvals != lensubs(1))) error ("accumarray: dimension mismatch"); endif else ndims = columns (subs); if (lenvals > 1 && lenvals != rows (subs)) error ("accumarray: dimension mismatch"); endif endif if (isempty (fillval)) fillval = 0; endif if (isempty (issparse)) issparse = false; endif if (issparse) ## Sparse case. Avoid linearizing the subscripts, because it could ## overflow. if (fillval != 0) error ("accumarray: FILLVAL must be zero in the sparse case"); endif ## Ensure subscripts are a two-column matrix. if (iscell (subs)) subs = [subs{:}]; endif ## Validate dimensions. if (ndims == 1) subs(:,2) = 1; elseif (ndims != 2) error ("accumarray: in the sparse case, needs 1 or 2 subscripts"); endif if (isnumeric (vals) || islogical (vals)) vals = double (vals); else error ("accumarray: in the sparse case, values must be numeric or logical"); endif if (! (isempty (func) || func == @sum)) ## Reduce values. This is not needed if we're about to sum them, ## because "sparse" can do that. ## Sort indices. [subs, idx] = sortrows (subs); n = rows (subs); ## Identify runs. jdx = find (any (diff (subs, 1, 1), 2)); jdx = [jdx; n]; vals = cellfun (func, mat2cell (vals(:)(idx), diff ([0; jdx]))); subs = subs(jdx, :); mode = "unique"; else mode = "sum"; endif ## Form the sparse matrix. if (isempty (sz)) A = sparse (subs(:,1), subs(:,2), vals, mode); elseif (length (sz) == 2) ## Row vector case if (sz(1) == 1) [i, j] = deal (subs(:,2), subs(:,1)); else [i, j] = deal (subs(:,1), subs(:,2)); endif A = sparse (i, j, vals, sz(1), sz(2), mode); else error ("accumarray: dimensions mismatch"); endif else ## Linearize subscripts. if (ndims > 1) if (isempty (sz)) if (iscell (subs)) sz = cellfun ("max", subs); else sz = max (subs, [], 1); endif elseif (ndims != length (sz)) error ("accumarray: dimensions mismatch"); endif ## Convert multidimensional subscripts. if (isnumeric (subs)) subs = num2cell (subs, 1); endif subs = sub2ind (sz, subs{:}); # creates index cache elseif (! isempty (sz) && length (sz) < 2) error ("accumarray: needs at least 2 dimensions"); elseif (! isindex (subs)) # creates index cache error ("accumarray: indices must be positive integers"); endif ## Some built-in reductions handled efficiently. if (isempty (func) || func == @sum) ## Fast summation. if (isempty (sz)) A = __accumarray_sum__ (subs, vals); else A = __accumarray_sum__ (subs, vals, prod (sz)); ## set proper shape. A = reshape (A, sz); endif ## we fill in nonzero fill value. if (fillval != 0) mask = true (size (A)); mask(subs) = false; A(mask) = fillval; endif elseif (func == @max) ## Fast maximization. if (isinteger (vals)) zero = intmin (class (vals)); elseif (islogical (vals)) zero = false; elseif (fillval == 0 && all (vals(:) >= 0)) ## This is a common case - fillval is zero, all numbers ## nonegative. zero = 0; else zero = NaN; # Neutral value. endif if (isempty (sz)) A = __accumarray_max__ (subs, vals, zero); else A = __accumarray_max__ (subs, vals, zero, prod (sz)); A = reshape (A, sz); endif if (fillval != zero && ! (isnan (fillval) || isnan (zero))) mask = true (size (A)); mask(subs) = false; A(mask) = fillval; endif elseif (func == @min) ## Fast minimization. if (isinteger (vals)) zero = intmax (class (vals)); elseif (islogical (vals)) zero = true; elseif (fillval == 0 && all (vals(:) <= 0)) ## This is a common case - fillval is zero, all numbers ## non-positive. zero = 0; else zero = NaN; # Neutral value. endif if (isempty (sz)) A = __accumarray_min__ (subs, vals, zero); else A = __accumarray_min__ (subs, vals, zero, prod (sz)); A = reshape (A, sz); endif if (fillval != zero && ! (isnan (fillval) || isnan (zero))) mask = true (size (A)); mask(subs) = false; A(mask) = fillval; endif else ## The general case. Reduce values. n = rows (subs); if (numel (vals) == 1) vals = vals(ones (1, n), 1); else vals = vals(:); endif ## Sort indices. [subs, idx] = sort (subs); ## Identify runs. jdx = find (subs(1:n-1) != subs(2:n)); jdx = [jdx; n]; vals = mat2cell (vals(idx), diff ([0; jdx])); ## Optimize the case when function is @(x) {x}, i.e. we just want ## to collect the values to cells. persistent simple_cell_str = func2str (@(x) {x}); if (! strcmp (func2str (func), simple_cell_str)) vals = cellfun (func, vals); endif subs = subs(jdx); if (isempty (sz)) sz = max (subs); if (length (sz) == 1) sz(2) = 1; endif endif ## Construct matrix of fillvals. if (iscell (vals)) A = cell (sz); elseif (fillval == 0) A = zeros (sz, class (vals)); else A = repmat (fillval, sz); endif ## Set the reduced values. A(subs) = vals; endif endif endfunction %!assert (accumarray ([1;2;4;2;4],101:105), [101;206;0;208]) %!assert (accumarray ([1,1,1;2,1,2;2,3,2;2,1,2;2,3,2],101:105), cat (3, [101,0,0;0,0,0],[0,0,0;206,0,208])) %!assert (accumarray ([1,1,1;2,1,2;2,3,2;2,1,2;2,3,2],101:105,[],@(x)sin(sum(x))), sin (cat (3, [101,0,0;0,0,0],[0,0,0;206,0,208]))) %!assert (accumarray ({[1 3 3 2 3 1 2 2 3 3 1 2],[3 4 2 1 4 3 4 2 2 4 3 4],[1 1 2 2 1 1 2 1 1 1 2 2]},101:112), cat (3, [0,0,207,0;0,108,0,0;0,109,0,317], [0,0,111,0;104,0,0,219;0,103,0,0])) %!assert (accumarray ([1,1;2,1;2,3;2,1;2,3],101:105,[2,4],@max,NaN), [101,NaN,NaN,NaN;104,NaN,105,NaN]) %!assert (accumarray ([1 1; 2 1; 2 3; 2 1; 2 3],101:105, [], @prod), [101, 0, 0; 10608, 0, 10815]) %!assert (accumarray ([1 1; 2 1; 2 3; 2 1; 2 3],101:105,[2 4],@prod,0,true), sparse ([1,2,2],[1,1,3],[101,10608,10815],2,4)) %!assert (accumarray ([1 1; 2 1; 2 3; 2 1; 2 3],1,[2,4]), [1,0,0,0;2,0,2,0]) %!assert (accumarray ([1 1; 2 1; 2 3; 2 1; 2 3],101:105,[2,4],@(x)length(x)>1), [false,false,false,false;true,false,true,false]) %!assert (accumarray ([1; 2], [3; 4], [2, 1], @min, [], 0), [3; 4]) %!assert (accumarray ([1; 2], [3; 4], [2, 1], @min, [], 1), sparse ([3; 4])) %!assert (accumarray ([1; 2], [3; 4], [1, 2], @min, [], 0), [3, 4]) %!assert (accumarray ([1; 2], [3; 4], [1, 2], @min, [], 1), sparse ([3, 4])) %!test %! A = accumarray ([1 1; 2 1; 2 3; 2 1; 2 3], 101:105, [2,4], @(x){x}); %! assert (A{2},[102;104]); %!test %! subs = ceil (rand (2000, 3)*10); %! vals = rand (2000, 1); %! assert (accumarray (subs, vals, [], @max), accumarray (subs, vals, [], @(x) max (x))); %!test %! subs = ceil (rand (2000, 1)*100); %! vals = rand (2000, 1); %! assert (accumarray (subs, vals, [100, 1], @min, NaN), accumarray (subs, vals, [100, 1], @(x) min (x), NaN)); %!test %! subs = ceil (rand (2000, 2)*30); %! subsc = num2cell (subs, 1); %! vals = rand (2000, 1); %! assert (accumarray (subsc, vals, [], [], 0, true), accumarray (subs, vals, [], [], 0, true)); %!test %! subs = ceil (rand (2000, 3)*10); %! subsc = num2cell (subs, 1); %! vals = rand (2000, 1); %! assert (accumarray (subsc, vals, [], @max), accumarray (subs, vals, [], @max)); %!error (accumarray (1:5)) %!error (accumarray ([1,2,3],1:2))