# tensorplay.func.linearize

Source: https://www.tensorplay.cn/docs/generated/tensorplay.func.linearize.html

```python
tensorplay.func.linearize(func: Callable, *primals) → tuple[Any, Callable]
```

Evaluates func at primals and returns its linear approximation
there.

The primal evaluation happens once, here; the returned jvp_fn reuses
that linearization, so applying it to many tangents costs only the tangent
passes.  Use it in place of repeated [jvp()](/docs/generated/tensorplay.func.jvp.html#tensorplay.func.jvp) calls at a fixed point.

Returns:

(output, jvp_fn).  jvp_fn takes tangents matching the structure
of primals and returns the directional derivative of the output.

Example

```
>>> x = tensorplay.randn(5)
>>> out, jvp_fn = linearize(tensorplay.sin, x)
>>> tangent_out = jvp_fn(tensorplay.ones(5))
```