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function pdf = ChiSquarePDF(x,df)
% pdf = ChiSquarePDF(x,df)
%
% Returns ChiSquare pdf of value x with df d.f. x may be a matrix. df must
% be a scalar.
%
% Based on Pocket Book of Integrals and Mathematical Functions Ronald J.
% Tallarida, CRC Press, 1991, p. 103
%
% Denis G. Pelli, 1993
%
% 5/19/96 dhb Cosmetic changes.
% 7/24/04 awi Cosmetic.
if (nargin ~= 2)
error('Usage: pdf = ChiSquarePDF(x,df)');
end
if (df < 1)
error('ChiSquarePDF: degrees of freedom must be at least 1');
end
pdf=exp(-x/2).*x.^((df-2)/2)/(2^(df/2)*gamma(df/2));
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