octave-symbolic 2.2.4-1 / usr / share / octave / packages / symbolic-2.2.4 / sympref.m

%% Copyright (C) 2014, 2015 Colin B. Macdonald
%%
%% This file is part of OctSymPy.
%%
%% OctSymPy 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 software 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 software; see the file COPYING.
%% If not, see <http://www.gnu.org/licenses/>.

%% -*- texinfo -*-
%% @documentencoding UTF-8
%% @deftypefn  {Function File} {@var{r} =} sympref ()
%% @deftypefnx {Function File} {@var{r} =} sympref (@var{cmd})
%% @deftypefnx {Function File} {} sympref @var{cmd}
%% @deftypefnx {Function File} {} sympref @var{cmd} @var{args}
%% Preferences for the OctSymPy symbolic computing package.
%%
%% @code{sympref} can set or get various preferences and
%% configurations.  The various choices for @var{cmd} and
%% @var{args} are documented below.
%%
%%
%% @strong{Python executable} path/command:
%% @example
%% @group
%% >> sympref python '/usr/bin/python'       @c doctest: +SKIP
%% >> sympref python 'C:\Python\python.exe'  @c doctest: +SKIP
%% >> sympref python 'N:\myprogs\py.exe'     @c doctest: +SKIP
%% @end group
%% @end example
%% Default is an empty string; in which case OctSymPy just runs
%% @code{python} and assumes the path is set appropriately.
%%
%% @strong{Display} of syms:
%% @example
%% @group
%% >> sympref display
%%    @result{} ans = unicode
%% @end group
%% @group
%% >> syms x
%% >> sympref display flat
%% >> sin(x/2)
%%    @result{} (sym) sin(x/2)
%%
%% >> sympref display ascii
%% >> sin(x/2)
%%    @result{} (sym)
%%              /x\
%%           sin|-|
%%              \2/
%%
%% >> sympref display unicode
%% >> sin(x/2)
%%    @result{} (sym)
%%              ⎛x⎞
%%           sin⎜─⎟
%%              ⎝2⎠
%%
%% >> sympref display default
%% @end group
%% @end example
%% By default OctSymPy uses the unicode pretty printer to display
%% symbolic expressions.  If that doesn't work (e.g., if you
%% see @code{?} characters) then try the @code{ascii} option.
%%
%% @strong{Communication mechanism}:
%% @example
%% >> sympref ipc
%%    @result{} ans = default
%% @end example
%% The default will typically be the @code{popen2} mechanism which
%% uses a pipe to communicate with Python and should be fairly fast.
%% If that doesn't work, try @code{sympref display system} which is
%% much slower, as a new Python
%% process is started for each operation (many commands use more
%% than one operation).
%% Other options for @code{sympref ipc} include:
%% @itemize
%% @item @code{sympref ipc popen2}: force popen2 choice (e.g.,
%% on Matlab were it would not be the default).
%% @item @code{sympref ipc system}: construct a long string of
%% the command and pass it directly to the python interpreter with
%% the @code{system()} command.  This typically assembles a multiline
%% string for the commands, except on Windows where a long one-line
%% string is used.
%% @item @code{sympref ipc systmpfile}: output the python commands
%% to a @code{tmp_python_cmd.py} file and then call that [for
%% debugging, may not be supported long-term].
%% @item @code{sympref ipc sysoneline}: put the python commands all
%% on one line and pass to @code{python -c} using a call to @code{system()}.
%% [for debugging, may not be supported long-term].
%% @end itemize
%%
%% @strong{Reset}: reset the SymPy communication mechanism.  This can be
%% useful after an error occurs and the connection with Python
%% becomes confused.
%% @example
%% >> sympref reset     @c doctest: +SKIP
%% @end example
%%
%% @strong{Snippets}: when displaying a sym object, we quote the SymPy
%% representation (or a small part of it):
%% @example
%% @group
%% >> syms x
%% >> y = [pi x];
%% >> sympref snippet on
%% >> y
%%    @result{} y = (sym 1×2 matrix)       “...([[pi, Symbol('x')]])”
%%        [π  x]
%% >> sympref snippet off
%% >> y
%%    @result{} y = (sym) [π  x]  (1×2 matrix)
%% >> sympref snippet default
%% @end group
%% @end example
%%
%% @strong{Default precision}: control the number of digits used by
%% variable-precision arithmetic (see also the @ref{digits} command).
%% @example
%% @group
%% >> sympref digits          % get
%%    @result{} ans = 32
%% >> sympref digits 64       % set
%% >> sympref digits default
%% @end group
%% @end example
%%
%%
%% Report the @strong{version} number:
%% @example
%% @group
%% >> sympref version
%%    @result{} 2.2.4
%% @end group
%% @end example
%%
%% @seealso{sym, syms}
%% @end deftypefn

function varargout = sympref(cmd, arg)

  persistent settings

  if (isempty(settings))
    settings = 42;
    sympref('defaults')
  end

  if (nargin == 0)
    varargout{1} = settings;
    return
  end


  switch lower(cmd)
    case 'defaults'
      settings = [];
      settings.ipc = 'default';
      settings.whichpython = '';
      sympref ('display', 'default')
      sympref ('digits', 'default')
      sympref ('snippet', 'default')

    case 'version'
      assert (nargin == 1)
      varargout{1} = '2.2.4';

    case 'display'
      if (nargin == 1)
        varargout{1} = settings.display;
      else
        arg = lower (arg);
        if (strcmp (arg, 'default'))
          arg = 'unicode';
          if (ispc () && (~isunix ()))
            % Unicode not working on Windows, Issue #83.
            arg = 'ascii';
          end
        end
        assert(strcmp(arg, 'flat') || strcmp(arg, 'ascii') || ...
               strcmp(arg, 'unicode'))
        settings.display = arg;
      end

    case 'digits'
      if (nargin == 1)
        varargout{1} = settings.digits;
      else
        if (ischar(arg))
          if (strcmpi(arg, 'default'))
            arg = 32;
          else
            arg = str2double(arg);
          end
        end
        arg = int32(arg);
        assert(arg > 0, 'precision must be positive')
        settings.digits = arg;
      end

    case 'snippet'
      if (nargin == 1)
        varargout{1} = settings.snippet;
      else
	if (strcmpi(arg, 'default'))
	  settings.snippet = false;  % Should be false for a release
	else
          settings.snippet = tf_from_input(arg);
	end
      end

    case 'python'
      if (nargin == 1)
        varargout{1} = settings.whichpython;
      elseif (isempty(arg) || strcmp(arg,'[]'))
        settings.whichpython = '';
        sympref('reset')
      else
        settings.whichpython = arg;
        sympref('reset')
      end

    case 'ipc'
      if (nargin == 1)
        varargout{1} = settings.ipc;
      else
        sympref('reset')
        settings.ipc = arg;
        switch arg
          case 'default'
            disp('Choosing the default [autodetect] octsympy communication mechanism')
          case 'system'
            disp('Forcing the system() octsympy communication mechanism')
          case 'popen2'
            disp('Forcing the popen2() octsympy communication mechanism')
          case 'systmpfile'
            disp('Forcing systmpfile ipc: warning: this is for debugging')
          case 'sysoneline'
            disp('Forcing sysoneline ipc: warning: this is for debugging')
          otherwise
            warning('Unsupported IPC mechanism: hope you know what you''re doing')
        end
      end

    case 'reset'
      disp('Resetting the octsympy communication mechanism');
      r = python_ipc_driver('reset', []);

      if (nargout == 0)
        if (~r)
          disp('Problem resetting');
        end
      else
        varargout{1} = r;
      end

    %case 'path'
      %pkg_path = fileparts (mfilename ('fullpath'));
      % or
      %pkg_l = pkg ('list');
      %idx = strcmp ('octsympy', cellfun (@(x) x.name, pkg_l, "UniformOutput", false));
      %if (~ any (idx))
      %  error ('the package %s is not installed', your_pkg);
      %end
      %pkg_path = pkg_l{idx}.dir

    otherwise
      print_usage ();
  end
end


function r = tf_from_input(s)

  if (~ischar(s))
    r = logical(s);
  elseif (strcmpi(s, 'true'))
    r = true;
  elseif (strcmpi(s, 'false'))
    r = false;
  elseif (strcmpi(s, 'on'))
    r = true;
  elseif (strcmpi(s, 'off'))
    r = false;
  elseif (strcmpi(s, '[]'))
    r = false;
  else
    r = str2double(s);
    assert(~isnan(r), 'invalid expression to convert to bool')
    r = logical(r);
  end
end


%!test
%! % system should work on all system, but just runs sysoneline on windows
%! fprintf('\nRunning some tests that reset the IPC and produce output\n');
%! sympref('ipc', 'system');
%! pause(1);
%! syms x
%! pause(2);

%!test
%! % sysoneline should work on all systems
%! fprintf('\n');
%! sympref('ipc', 'sysoneline');
%! pause(1);
%! syms x
%! pause(2);

%!test
%! sympref('defaults')
%! assert(strcmp(sympref('ipc'), 'default'))

%!test
%! fprintf('\n');
%! syms x
%! r = sympref('reset');
%! pause(1);
%! syms x
%! pause(2);
%! assert(r)