function f = plognorm(x,lambda,zeta)
%PLOGNORM The log-normal distribution function
%
% f = plognorm(x, lambda, zeta)
% Copyright (c) Halfdan Grage, Anders Holtsberg
if any(any(zeta<=0))
error('Parameter zeta is wrong')
end
neg = find(x <= 0);
[n1,n2] = size(neg);
x(neg) = ones(n1,n2);
f = pnorm(log(x),lambda,zeta);
f(neg) = zeros(n1,n2);
