function p = twomodegauss(m1, sig1, m2, sig2, A1, A2, k)
%TWOMODEGAUSS Generates a two-mode Gaussian function.
% P = TWOMODEGAUSS(M1, SIG1, M2, SIG2, A1, A2, K) generates a
% two-mode, Gaussian-like function in the interval [0,1]. P is a
% 256-element vector normalized so that SUM(P) equals 1. The mean
% and standard deviation of the modes are (M1, SIG1) and (M2,
% SIG2), respectively. A1 and A2 are the amplitude values of the
% two modes. Since the output is normalized, only the relative
% values of A1 and A2 are important. K is an offset value that
% raises the "floor" of the function. A good set of values to try
% is M1=0.15, S1=0.05, M2=0.75, S2=0.05, A1=1, A2=0.07, and
% K=0.002.
% Copyright 2002-2004 R. C. Gonzalez, R. E. Woods, & S. L. Eddins
% Digital Image Processing Using MATLAB, Prentice-Hall, 2004
% $Revision: 1.6 $ $Date: 2003/10/13 00:54:47 $
c1 = A1 * (1 / ((2 * pi) ^ 0.5) * sig1);
k1 = 2 * (sig1 ^ 2);
c2 = A2 * (1 / ((2 * pi) ^ 0.5) * sig2);
k2 = 2 * (sig2 ^ 2);
z = linspace(0, 1, 256);
p = k + c1 * exp(-((z - m1) .^ 2) ./ k1) + ...
c2 * exp(-((z - m2) .^ 2) ./ k2);
p = p ./ sum(p(:));
