Description gampdf ( x, a, b) computes the gamma pdf at each of the values in x using the corresponding parameters in a and b. downloads updated view license follow download overview functions version history reviews ( 1) discussions ( 0) plotting the gamma function for different shape parameter values. example y = gampdf ( x, a, b) returns the pdf of the gamma distribution with the shape parameter a and the scale parameter b, evaluated at the values in x. matlab code for ploting the pdf of the gamma function. vector or matrix inputs for x, a, and b must all be the same size. for integer n: gamma ( n+ 1) = factorial ( n) = prod ( 1: n) the domain of the gamma function extends to negative real numbers by analytic continuation, with simple poles at the negative. the gamma function interpolates the factorial function. description y = pdf ( name, x, a) returns the probability density function ( pdf) for the one- matlab parameter distribution family specified by name and the distribution parameter a, evaluated at the values in x. y = gampdf ( x, a) returns the probability density function ( pdf) of the standard gamma distribution with the shape parameter a, evaluated at the values in x. cite as jamal ahmad ( ). the gamma function is defined for real x > 0 by the integral: γ ( x) = ∫ 0 ∞ e t t x 1 d t. the pdf of the gamma distribution is y = f ( x■ a, b) = 1baγ( a) xa 1e xb, where γ ( · ) is the gamma function. examples collapse all compute gamma pdf. for an example, see compute gamma distribution pdf. cumulative distribution function the cumulative distribution function ( cdf) of the gamma distribution is p = f ( x■ a, b) = 1baγ( a) x ∫ 0 ta gamma pdf matlab 1e tbdt. a scalar input is expanded to a constant matrix with the same dimensions as the other inputs.