Regularized Incomplete Beta function
y = distfun_betainc(x,z,w) y = distfun_betainc(x,z,w,lowertail)
a matrix of doubles, the outcome. Should be in the [0,1] interval. If not, an error is generated.
a matrix of doubles, the first shape parameter, z>=0.
a matrix of doubles, the second shape parameter, w>=0.
a 1-by-1 matrix of booleans, the tail (default lowertail=%t). If lowertail is true (the default), then computes the integral from 0 to x otherwise from x to 1.
a matrix of doubles, the output, y in [0,1].
Computes the regularized Incomplete Beta function.
The Beta function is defined by
The incomplete Beta function is defined by
if x is in [0,1].
The (lower tail) regularized incomplete Beta function is defined by
if x is in [0,1].
The upper tail regularized incomplete Beta function is defined by
if x is in [0,1] where the upper tail of the incomplete Beta function is
The sum of the lower and upper tail is equal to 1 :