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CINV |
Category: | Quantile |
Syntax | |
Arguments | |
Details | |
Examples |
Syntax |
CINV (p,df<,nc>) |
Range: | 0 p < 1 |
Range: | df> 0 |
Range: | nc 0 |
Details |
The CINV function returns the p^{th} quantile from the chi-square distribution with degrees of freedom df and a noncentrality parameter nc. The probability that an observation from a chi-square distribution is less than or equal to the returned quantile is p. This function accepts a noninteger degrees of freedom parameter df.
If the optional parameter nc is not specified or has the value 0, the quantile from the central chi-square distribution is returned. The noncentrality parameter nc is defined such that if X is a normal random variable with mean and variance 1, X^{2} has a noncentral chi-square distribution with df=1 and nc = ^{2}.
Note: CINV is the inverse of the PROBCHI function.
Examples |
These statements show how to find the 95^{th} percentile from a central chi-square distribution with 3 degrees of freedom and the 95^{th} percentile from a noncentral chi-square distribution with 3.5 degrees of freedom and a noncentrality parameter equal to 4.5.
SAS Statements | Results |
---|---|
q1=cinv(.95,3); |
7.8147279033 |
a2=cinv(.95,3.5,4.5); |
7.504582117 |
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