This is documentation for an old release of SciPy (version 0.13.0). Read this page Search for this page in the documentation of the latest stable release (version 1.15.1).

scipy.special.nbdtri

scipy.special.nbdtri(x1, x2, x3[, out]) = <ufunc 'nbdtri'>

p=nbdtri(k,n,y) finds the argument p such that nbdtr(k,n,p)=y.