# tf.math.polygamma

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

tf.math.polygamma(
a, x, name=None
)


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\.

#### Args:

• 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).

#### Returns:

A Tensor. Has the same type as a.