# tf.math.polygamma

Compute the polygamma function $$\psi^{(n)}(x)$$.

The polygamma function is defined as:

$$\psi^{(a)}(x) = \frac{d^a}{dx^a} \psi(x)$$

where $$\psi(x)$$ is the digamma function. The polygamma function is defined only for non-negative integer orders \a\.

a A Tensor. Must be one of the following types: float32, float64.
x A Tensor. Must have the same type as a.
name A name for the operation (optional).

A Tensor. Has the same type as a.