search for: gammafunction

Displaying 1 result from an estimated 1 matches for "gammafunction".

2008 May 23
1
maximizing the gamma likelihood
for learning purposes and also to help someone, i used roger peng's document to get the mle's of the gamma where the gamma is defined as f(y_i) = (1/gammafunction(shape)) * (scale^shape) * (y_i^(shape-1)) * exp(-scale*y_i) ( i'm defining the scale as lambda rather than 1/lambda. various books define it differently ). i found the likelihood to be n*shape*log(scale) + (shape-1)*sum(log(y_i) - scale*sum(y_i) then i wrote below which is just roger pen...