Manuals/calci/GAMMAINV
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GAMMAINV(prob,alpha,beta)
- Where 'prob' is the probability value associated with gamma distribution
- 'Alpha'& 'beta' are the values of the shape and rate parameters
Description
- This function gives the inverse value of cumulative gamma probability distribution.
- This distribution is the continuous probability distribution on the positive real line and it is of the reciprocal of a variable distributed according to the gamma distribution with two parameters α&ß.
- It is used in Bayesian statistics.
- In GAMMAINV(prob,alpha,beta) , prob is the probability value associated with gamma distribution,alpha is called shape parameter and beta is the rate parameter of the distribution.
- .If GAMMADIST(x,alpha,beta,TRUE)=prob, then GAMMAINV(prob,alpha,beta,)=x.
- GAMMAINV using the iterating method to find the value of x.suppose the iteration has not converged after 100 searches, then the function gives the error result.
- This function will give the error result when
- Any one of the arguments are nonnumeric
- alpha or beta<=0
- prob<0 or prob>1
Examples
- GAMMAINV(0.65189,2,5)=11.1335534510
- GAMMAINV(0.006867292,5,7)=8.155481331GAMMAINV(0.1543869,9,3)=18.0467153645
- GAMMAINV(1,9,3)=82.51739521528073(CALCI)=119.4248486(EXCEL)
- GAMMAINV(1.1,9,3)=NAN, because prob>1