Mercurial > forge
view main/miscellaneous/inst/apply.m @ 2959:610db3cb68da octave-forge
apply.m: uses feval to apply(func_handle,{arg1,arg2, .. .argn});
map.m: modified to work with function handles, and uses apply removing older eval code
author | gnumuthu |
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date | Tue, 23 Jan 2007 18:18:42 +0000 |
parents | |
children | 2de537641f94 |
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## Copyright (C) 2007, Muthiah Annamalai ## ## Apply function like in LISP. Pass a (row only)cell-array of arguments, ## supplied on invoking the function. ## ## 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 of the License, 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 program; if not, write to the Free Software ## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA ## ## -*- texinfo -*- ## @deftypefn {Loadable Function} {@var{return_value} =} apply (@var{@@function_handle},@var{cell_array_of_args}) ## @deftypefnx {Loadable Function} {@var{return_value} =} apply (@var{@@function_handle}) ## Apply calls the function @var{function_handle} with the arguments of the cell ## array @var{cell_array_of_args} which contains the actual arguments arg1,arg2,..., argn ## to the function, in that order. Apply invokes the function as ## @var{function_handle}(arg1, arg2, ... ,argn), where the arguments are ## extracted from each elements of the 1-row cell array @var{cell_array_of_args}. ## ## Apply also works on array of function handles if ## @var{function_handle} is passed as a cell array of a handles; in this ## case apply, evaluates each function (using the handle) with the same ## arguments. ## ## The cell-array argument is optional second argument, in the form ## of a 1-row with multiple elements. The elements of the cell-array ## form the actual arguments supplied when invoking the function @var{function_handle}. ## ## The return value depends on the function invoked, and the validity of ## the arguments. ## ## @example ## z=apply(@@sqrt,cell([1,2; 3,4])); ## z=apply(@@apply,cell(@@sqrt,cell([1,2; 3,4]))); ## apply(@@sum,cell([1,2,3,4])) ## apply(@@max,cell([1,2,3,4])) ## apply(@@min,cell([1,2,3,4])) ## @end example ## ## ## In first case, apply computes the sqrt of the matrix [1,2; 3,4]; ## The second example is meta-apply, using apply on itself. ## The rest of the examples invoke sum, max, min respectively. ## @end deftypefn ## function rval=apply(fun_handle,cell_array) if (nargin == 0) print_usage(); error("apply(): needs at least 1 argument, see usage"); elseif( nargin < 2) if iscell(fun_handle) for idx=1:length(fun_handle) rval(idx)=feval(@feval,fun_handle{idx}); end else rval=feval(@feval,fun_handle); end return elseif(!iscell(cell_array)) error("apply(): needs second argument, to be a cell-array"); end if iscell(fun_handle) for idx=1:length(fun_handle) rval(idx)=feval(@feval,fun_handle{idx},cell_array{:}); end return end rval=feval(@feval,fun_handle,cell_array{:}); end %! %!assert(apply({@min, @max, @mean},{[1:10]}),[ 1.0000 ,10.0000 ,5.5000]) %!assert(apply(@min,{[1,2,3,4]}),1) %!assert(apply(@dot,{[1,2],[3,4]}),11) %!assert(apply(@min,{[1, 3]}),1) %!assert(apply(@sum,{[1:10]}),55) %!assert(apply(@sqrt,{[1,2; 3,4]}),sqrt([1,2;3,4])) %!assert(apply(@apply,{@sqrt,{[1,2; 3,4]}}),sqrt([1,2;3,4])) %!assert(apply(@sum,{[1,2,3,4]}),10) %!assert(apply(@max,{[1,2,3,4]}),4) %!assert(apply(@min,{[1,2,3,4]}),1) %!