Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / signal-1.1.3 / data2fun.m

diff --git a/octave_packages/signal-1.1.3/data2fun.m b/octave_packages/signal-1.1.3/data2fun.m
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+%% Copyright (c) 2011 Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+%%
+%% 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 3 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, see <http://www.gnu.org/licenses/>.
+
+%% -*- texinfo -*-
+%% @deftypefn {Function File} {[@var{fhandle}, @var{fullname}] = } data2fun (@var{ti}, @var{yi})
+%% @deftypefnx {Function File} {[ @dots{} ] = } data2fun (@var{ti}, @var{yi},@var{property},@var{value})
+%% Creates a vectorized function based on data samples using interpolation.
+%%
+%% The values given in @var{yi} (N-by-k matrix) correspond to evaluations of the
+%% function y(t) at the points @var{ti} (N-by-1 matrix).
+%% The data is interpolated and the function handle to the generated interpolant
+%% is returned.
+%%
+%% The function accepts property-value pairs described below.
+%%
+%% @table @samp
+%% @item file
+%% Code is generated and .m file is created. The @var{value} contains the name
+%% of the function. The returned function handle is a handle to that file. If
+%% @var{value} is empty, then a name is automatically generated using
+%% @code{tmpnam} and the file is created in the current directory. @var{value}
+%% must not have an extension, since .m will be appended.
+%% Numerical value used in the function are stored in a .mat file with the same
+%% name as the function.
+%%
+%% @item interp
+%% Type of interpolation. See @code{interp1}.
+%%
+%% @end table
+%%
+%% @seealso{interp1}
+%% @end deftypefn
+
+function [fhandle fullfname] = data2fun( t, y, varargin)
+
+  %% Check input arguments
+  interp_args = {"spline"};
+  given = struct("file",false);
+  if ~isempty(varargin)
+      % Arguments
+      interp_args = varargin;
+
+      opt_args = fieldnames (given);
+      [tf idx] = ismember( opt_args, varargin);
+      for i=1:numel(opt_args)
+        given.(opt_args{i}) = tf(i);
+      end
+
+      if given.file
+        %% TODO: check that file will be in the path. Otherwise fhabdle(0) fails.
+
+        if !isempty(varargin{idx(1)+1})
+
+          [DIR fname] = fileparts(varargin{idx(1)+1});
+
+        else
+
+          [DIR fname] = fileparts (tmpnam (pwd (),"agen_"));
+
+        end
+
+        interp_args(idx(1)+[0 1]) = [];
+      end
+
+      if isempty(interp_args)
+
+        interp_args = {"spline"};
+
+      end
+  end
+
+  pp = interp1 (t, y, interp_args{end}, 'pp');
+
+  if given.file
+    fullfname = fullfile (DIR,[fname ".m"]);
+    save("-binary",[fullfname(1:end-2) ".mat"],"pp");
+
+    bodystr = ["  persistent pp\n" ...
+                   "  if isempty(pp)\n" ...
+                   "    pp = load([mfilename()" ' ".mat"' "]).pp;\n"...
+                   "  end\n\n" ...
+                   "  z = ppval(pp, x);"];
+
+    strfunc = generate_function_str(fname, {"z"}, {"x"}, bodystr);
+
+    fid = fopen ( fullfile (DIR,[fname ".m"]), "w");
+    fprintf (fid, "%s", strfunc);
+    fclose (fid);
+
+    disp(["Function generated: " fullfname ]);
+    fhandle = eval(["@" fname]);
+
+  else
+    fullfname = "";
+    fhandle = @(t_) ppval (pp, t_);
+
+  end
+
+endfunction
+
+function str = generate_function_str(name, oargs, iargs, bodystr)
+
+  striargs = cell2mat ( cellfun (@(x) [x ", "], iargs, "UniformOutput", false));
+  striargs = striargs(1:end-2);
+
+  stroargs = cell2mat ( cellfun (@(x) [x ", "], oargs, "UniformOutput", false));
+  stroargs = stroargs(1:end-2);
+
+  if !isempty (stroargs)
+    str = ["function [" stroargs "] = " name "(" striargs ")\n\n" bodystr ...
+           "\n\nendfunction"];
+  else
+    str = ["function " name "(" striargs ")\n\n" bodystr ...
+           "\n\nendfunction"];
+  end
+
+endfunction
+
+%!shared t, y
+%! t = linspace(0,1,10);
+%! y = t.^2 - 2*t + 1;
+
+%!test
+%! fhandle = data2fun(t,y);
+%! assert(y,fhandle(t));
+
+%!test
+%! [fhandle fname] = data2fun(t,y,"file","testdata2fun");
+%! yt = testdata2fun(t);
+%!
+%! assert(y,yt);
+%! assert(y,fhandle(t));
+%!
+%! delete(fname);
+%! delete([fname(1:end-2) ".mat"]);
+
+%!test
+%! [fhandle fname] = data2fun(t,y,"file","");
+%! yt = testdata2fun(t);
+%!
+%! assert(y,yt);
+%! assert(y,fhandle(t));
+%!
+%! delete(fname);
+%! delete([fname(1:end-2) ".mat"]);
+
+%!test
+%! [fhandle fname] = data2fun(t,y,"file","testdata2fun","interp","linear");
+%! yt = testdata2fun(t);
+%!
+%! assert(y,yt);
+%! assert(y,fhandle(t));
+%!
+%! delete(fname);
+%! delete([fname(1:end-2) ".mat"]);