Inverse Gamma distribution

I hate loading whole libraries for quick one line distributions.

dinvgamma=function(x,a,b){exp(a*log(b) - lgamma(a) - (a+1)*log(x) - b*1.0/x)}

rinvgamma=function(n,a,b){1/rgamma(n,a,b)}  #at one point the MCMCpack library has this function with different parameters for Windows and Unix 

                                                     

 

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