int.m

matlab 多参数积分工具箱 multivariable calculus toolbox

function I=int(S,varargin)
%INT  Integrates a scalar function.
%   I = INT(S,DIM) where S is the scalar function to
%   integrate and DIM a vector containing any of the numbers
%   1, 2 and 3.
%   I = INT(S,DIM1,DIM2,...) where DIM is either 1, 2 or 3 or
%   a string containing the variable name of which to
%   integrate along.

% Copyright (c) 2001-08-26, B. Rasmus Anthin.

I=S;
name=inputname(1);
[x y z]=vars(S);
if isempty(name)
   name=S.f;
   if ~isempty(S.xval)
      name=strrepx(name,x,S.xval,'pdiff');
   end
   if ~isempty(S.yval)
      name=strrepx(name,y,S.yval,'pdiff');
   end
   if ~isempty(S.zval)
      name=strrepx(name,z,S.zval,'pdiff');
   end
end
[h1,h2,h3]=coeffs(S);
if nargin==2 & isnumeric(varargin{1})
   dvar=varargin{1};
else
   dvar=[];
   for i=1:nargin-1
      switch(varargin{i})
      case {1,x}, dvar=[dvar 1];
      case {2,y}, dvar=[dvar 2];
      case {3,z}, dvar=[dvar 3];
      otherwise, error('Wrong type of index.')
      end
   end
end
%if length(dvar)>3 | ~length(dvar)
%   error('There must be 1 to 3 integration variables.')
%end
iax='[]';iay='[]';iaz='[]';
intch=repmat('