Method on @infsup: gammaln (X)

Compute the logarithm of the gamma function for positive arguments.

                   ∞
                  /
gammaln (x) = log |t^(x-1) exp (-t) dt
                  /
                 0

Accuracy: The result is a tight enclosure.

gammaln (infsup (1.5))
  ⇒ ans ⊂ [-0.12079, -0.12078]

See also: @infsup/psi, @infsup/gamma, @infsup/factorial.

Package: interval