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

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

See the guide: Math > Basic Math Functions

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

The polygamma function is defined as:

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


where $$\psi(x)$$ is the digamma function.

#### 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.

Defined in tensorflow/python/ops/gen_math_ops.py.