John Maddock
John Maddock wrote:
Christian Henning wrote:
Hi John, thanks for your reply. Your answer is basically what the documentation describes. But, it still leaves me with question marks in my head.
Let me ask differently. How do I construct the the red curve in the second image? Parameters here are: Shape = 1 and Scale = 1.
With apologies, ignore my previous message, the first graph is correct, the second graph has an incorrect title: it shows how the gamma distribution varies when the shape = 3, and the scale changes. So the red curve on the second graph is for shape = 3, scale = 1.
I've just updated SVN to reflect this, and hopefully put an end to the confusion !
John.
Hello, I am confused about the graphs in Gamma Distribution documentation page: http://www.boost.org/doc/libs/1_39_0/libs/math/doc/sf_and_dist/html/math_too... The first (blue) curve in the first graph suggests that Gamma PDF(0.0, 0.5, 1.0) == 1.0. Is this correct? Shouldn't it go to infinity as x approaches 0? PDF(x, k, theta) = x^(k-1)*exp(-x/theta)/(theta^k*gamma(k)) PDF(0.0, 0.5, 1.0) = 0^(-0.5)*1/gamma(0.5) = 1/(0^0.5 * gamma(0.5)) = Inf In the second graph both first and third curves have scale = 2 and shape = 2, yet they look different. Am I missing something? Thank you Mikhail