3.5.3.1.1 BetacdfBetacdf-func
Description
Computes beta cumulative distribution function at x, with parameters a and b. The pair of parameters a and b must all be positive, and the values in x must lie on the interval [0,1]. The parameter tail determines the returned probability is the lower tailed or upper tailed.
Syntax
double prob = betacdf(double x, double a, double b[, int tail])
Parameters
x
- Input, the value of the x variate, must lie on the interval [0, 1].
a
- Input, the first shape parameter, a, of the required beta distribution, must be positive( a>0 ).
b
- Input, the second shape parameter, b, of the required beta distribution, must be positive ( b>0 ).
tail
- Input, Optional. The tail probability type using for the beta distribution
- 1 = the for upper tail probability
- 2 = the lower tail probability (Default if not set)
prob
- Output. The probability that a single observation from a beta distribution with parameters a and b will fall in the interval [0, x] for upper tailed and [x, 1] for the lower tailed.
Example
aa = betacdf(1, 2, 2);
aa = ; //aa=1
betacdf(0.9,2,25,1)=; //betacdf(0.9,2,25,1)=2.35E-24
See Also
beta(a,b), incbeta(x,a,b)
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