%EVAL	Execute string containing MATLAB expression.
%	EVAL(s), where s is a string, causes MATLAB to execute
%	the string as an expression or statement.
%
%	EVAL(s1,s2) provides the ability to catch errors.  It
%	executes string s1 and returns if the operation was
%	successful. If the operation generates an error,
%	string s2 is evaluated before returning. Think of this
%	as EVAL('try','catch')
%	
%	[X,Y,Z,...] = EVAL(s) returns output arguments from the
%	expression in string s.
%
%	The input strings to EVAL are often created by 
%	concatenating substrings and variables inside square
%	brackets. For example:
%
%	Generate a sequence of matrices named M1 through M12:
%
%	    for n = 1:12
%	       eval(['M' num2str(n) ' = magic(n)'])
%	    end
%
%	Run a selected M-file script.  The strings making up 
%	the rows of matrix D must all have the same length.
%	
%	    D = ['odedemo '
%	         'quaddemo'
%	         'fitdemo '];
%	    n = input('Select a demo number: ');
%	    eval(D(n,:))
%
%	Read and process files with names data1.dat, data2.dat, ...
%
%	    k = 0;
%	    while 1
%	       k = k+1;
%	       datak = ['data' int2str(k)];
%	       filename = [datak '.dat'];
%	       if ~exist(filename), break, end
%	       eval(['load ' filename]);
%	       X = eval(datak);
%	       % Process data in matrix X.
%	    end
%
%	See also LASTERR, FEVAL.

%	Copyright (c) 1984-93 by The MathWorks, Inc.
%	Built-in function.
