function [errorcode,out1,out2,out3,out4] = distchck(nparms,arg1,arg2,arg3,arg4)
%DISTCHCK Checks the argument list for the probability functions.

%   B.A. Jones  1-22-93
%   Copyright (c) 1993-98 by The MathWorks, Inc.
%   $Revision: 2.6 $  $Date: 1997/11/29 01:45:12 $

errorcode = 0;

if nparms == 1
    out1 = arg1;
    return;
end
    
if nparms == 2
    [r1 c1] = size(arg1);
    [r2 c2] = size(arg2);
    scalararg1 = (prod(size(arg1)) == 1);
    scalararg2 = (prod(size(arg2)) == 1);
    if ~scalararg1 & ~scalararg2
        if r1 ~= r2 | c1 ~= c2
            errorcode = 1;
            return;         
        end     
    end
    if scalararg1
        out1 = arg1(ones(r2,1),ones(c2,1));
    else
        out1 = arg1;
    end
    if scalararg2
        out2 = arg2(ones(r1,1),ones(c1,1));
    else
        out2 = arg2;
    end
end
    
if nparms == 3
    [r1 c1] = size(arg1);
    [r2 c2] = size(arg2);
    [r3 c3] = size(arg3);
    scalararg1 = (prod(size(arg1)) == 1);
    scalararg2 = (prod(size(arg2)) == 1);
    scalararg3 = (prod(size(arg3)) == 1);

    if ~scalararg1 & ~scalararg2
        if r1 ~= r2 | c1 ~= c2
            errorcode = 1;
            return;         
        end
    end

    if ~scalararg1 & ~scalararg3
        if r1 ~= r3 | c1 ~= c3
            errorcode = 1;
            return;                 
        end
    end

    if ~scalararg3 & ~scalararg2
        if r3 ~= r2 | c3 ~= c2
            errorcode = 1;
            return;         
        end
    end

    if ~scalararg1
      out1 = arg1;
    end
    if ~scalararg2
      out2 = arg2;
    end
    if ~scalararg3
      out3 = arg3;
    end
    rows = max([r1 r2 r3]);
   columns = max([c1 c2 c3]);  
       
    if scalararg1
        out1 = arg1(ones(rows,1),ones(columns,1));
    end
   if scalararg2
        out2 = arg2(ones(rows,1),ones(columns,1));
   end
   if scalararg3
       out3 = arg3(ones(rows,1),ones(columns,1));
   end
     out4 =[];
    
end

if nparms == 4
    [r1 c1] = size(arg1);
    [r2 c2] = size(arg2);
    [r3 c3] = size(arg3);
    [r4 c4] = size(arg4);
    scalararg1 = (prod(size(arg1)) == 1);
    scalararg2 = (prod(size(arg2)) == 1);
    scalararg3 = (prod(size(arg3)) == 1);
    scalararg4 = (prod(size(arg4)) == 1);

    if ~scalararg1 & ~scalararg2
        if r1 ~= r2 | c1 ~= c2
            errorcode = 1;
            return;         
        end
    end

    if ~scalararg1 & ~scalararg3
        if r1 ~= r3 | c1 ~= c3
            errorcode = 1;
            return;                 
        end
    end

    if ~scalararg1 & ~scalararg4
        if r1 ~= r4 | c1 ~= c4
            errorcode = 1;
            return;                 
        end
    end

    if ~scalararg3 & ~scalararg2
        if r3 ~= r2 | c3 ~= c2
            errorcode = 1;
            return;         
        end
    end

    if ~scalararg4 & ~scalararg2
        if r4 ~= r2 | c4 ~= c2
            errorcode = 1;
            return;         
        end
    end

    if ~scalararg3 & ~scalararg4
        if r3 ~= r4 | c3 ~= c4
            errorcode = 1;
            return;         
        end
    end


    if ~scalararg1
       out1 = arg1;
    end
    if ~scalararg2
       out2 = arg2;
    end
    if ~scalararg3
      out3 = arg3;
    end
    if ~scalararg4
      out4 = arg4;
    end
 
   rows = max([r1 r2 r3 r4]);
   columns = max([c1 c2 c3 c4]);     
    if scalararg1
       out1 = arg1(ones(rows,1),ones(columns,1));
   end
   if scalararg2
       out2 = arg2(ones(rows,1),ones(columns,1));
   end
   if scalararg3
       out3 = arg3(ones(rows,1),ones(columns,1));
   end
   if scalararg4
       out4 = arg4(ones(rows,1),ones(columns,1));
   end
end