Doxygen Source Code Documentation
idummy.m
Go to the documentation of this file.00001 function d = idummy(x, method)
00002 %DUMMY Creates a matrix of dummy variables for a discrete variable
00003 % D=IDUMMY(X,METHOD) creates an array D of dummy variables for the
00004 % grouping variable I (integers 1,...,g), using the method specified:
00005 %
00006 % method = 1: 0/-1/1 coding, full rank
00007 % method = 2: 0/1 coding, full rank
00008 % method = 3: 0/1 coding, overdetermined
00009
00010 % Copyright 1993-2002 The MathWorks, Inc.
00011 % $Revision: 1.26 $ $Date: 2005/06/22 18:02:41 $
00012
00013 if (nargin < 2)
00014 method = 1;
00015 end
00016
00017 n = length(x);
00018 g = max(x);
00019 ncols = g - (method ~= 3);
00020 d = repmat(0, n, ncols);
00021
00022 if (g > 1)
00023 % Fill in -1 for the first level
00024 if (method == 1)
00025 i = find(x == 1);
00026 d(find(x == 1),:) = -1;
00027 end
00028
00029 % Fill in 1 in the appropriate column for other levels
00030 m3 = (method == 3);
00031 for j=(2-m3):g
00032 d(find(x == j),j-1+m3) = 1;
00033 end
00034 end
