fval.m

一个较好的MATLAB潮流程序

function val_out = fval(co,val_in,gtzero)
% FVAL sets parameters in graphical user interfaces
%
% OUT = FVAL(HDL,IN [,GTZERO])
%     HDL    object handle
%     IN     input value
%     GTZERO check if output value > 0
%            ( == 0 to disable,  default == 1)
%     OUT    output value
%
%Author:    Federico Milano
%Date:      11-Nov-2002
%Update:    22-Aug-2003
%Version:   1.1.0
%
%E-mail:    [e-mail]
%Web-site:  http://thunderbox.uwaterloo.ca/~fmilano
%
% Copyright (C) 2002-2005 Federico Milano
%
% This toolbox 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 2.0 of the License, or
% (at your option) any later version.
%
% This toolbox is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANDABILITY 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 toolbox; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307,
% USA.

if nargin == 2
  gtzero = 1;
end

stringa = get(co,'String');
callback = get(co,'Callback');
a = findstr(callback,' =');
if a,
  nome = ['"',callback(1:a(1)-1),'" '];
end

try
  val_out = eval(stringa);
catch
  val_out = val_in;
  fm_disp(lasterr,2);
  return
end
[a0, b0] = size(val_out);
if isempty(val_out)
  fm_disp(['Input variable or function "',stringa,'" is empty.'], 2)
  val_out = val_in;
  set(co,'String',num2str(val_in))
elseif (a0 > 1 | b0 > 1)
  if a,
    fm_disp(['Parameter ', nome,'has to be scalar.'], 2),
  end
  val_out = val_in;
  set(co,'String',num2str(val_in))
else
  if gtzero & val_out < 0
    stringa = '0';
    fm_disp(['Parameter ',nome,'cannot be negative.']),
    set(co,'String','0')
    val_out = 0;
  end
  if a,
    fm_disp(['Parameter ',nome,'set to "', stringa,'".']),
  end
end