Difference between revisions of "Manuals/calci/BETAINV"

Revision as of 01:11, 4 December 2013

BETAINV(prob,alpha,beta,a,b)

This function gives the inverse value of cumulative beta probability distribution.
It is called inverted beta function or beta prime.
In $BETAINV(prob,alpha,beta,a,b)$ , prob is the probability value of the associated with beta distribution, alpha and beta are the values of the two positive shape parameters and a and b are the lower and upper limit. *Normally the limit values are optional, i.e., when we are giving the values of a&b then the result value is from a and b, otherwise when we are omitting the values a and b by default it will consider a=0 and b=1, so the result value is from 0 and1.
If $BETADIST(x,alpha,beta,a,b)=prob$ , then $BETAINV(prob,alpha,beta,a,b)=x$ .
$BETAINV$ 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
x<a ,x>b, or a=b
we are not mentioning the limit values a and b, by default it will consider the standard cumulative beta distribution, a= 0 and b= 1.

BETAINV(0.2060381025,5,9,2,6)=3
BETAINV(0.359492343,8,10)=0.399999976(EXCEL) is approximate to 0.4=1.75(calci)
BETAINV(0.685470581,5,8,2,6)= 3.78378773(excel)=3.75(calci)
BETAINV(0.75267,1,7,7,9)=7.361844063(Excel)=7.25(calci)
BETAINV(0.5689,-2,4,3,5)=NAN, because alpha<0.

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 *In <math>BETAINV(prob,alpha,beta,a,b)</math>, prob is the probability value of the associated with beta distribution, alpha and beta are the values of the  two positive shape parameters and a and b are the lower and upper limit. *Normally the limit values are optional, i.e., when we are giving the values of a&b then the result value is from a and b, otherwise when we are omitting the values a and b by default it will consider a=0 and b=1, so the result value is from 0 and1.
 *If <math>BETADIST(x,alpha,beta,a,b)=prob</math>, then <math>BETAINV(prob,alpha,beta,a,b)=x</math>.
-*BETAINV 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.
+*<math>BETAINV</math> using the iterating method to find the value of <math>x</math>.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