# module `concrete.fhe.extensions.convolution`
Tracing and evaluation of convolution.
**Global Variables**
---------------
- **SUPPORTED_AUTO_PAD**
---
## function `conv`
```python
conv(
x: Union[ndarray, Tracer],
weight: Union[ndarray, List, Tracer],
bias: Optional[ndarray, List, Tracer] = None,
pads: Optional[Tuple[int, ], List[int]] = None,
strides: Optional[Tuple[int, ], List[int]] = None,
dilations: Optional[Tuple[int, ], List[int]] = None,
kernel_shape: Optional[Tuple[int, ], List[int]] = None,
group: int = 1,
auto_pad: str = 'NOTSET'
) → Union[ndarray, Tracer]
```
Trace and evaluate convolution operations.
Refer to https://github.com/onnx/onnx/blob/main/docs/Operators.md#Conv for more info.
**Args:**
- `x` (Union[np.ndarray, Tracer]): input of shape (N, C, D1, ..., DN)
- `weight` (Union[np.ndarray, Tracer]): kernel of shape (F, C / group, K1, ..., KN)
- `bias` (Optional[Union[np.ndarray, Tracer]], optional): bias of shape (F,). Defaults to None. pads (Optional[Union[Tuple[int, ...], List[int]]], optional): padding for the beginning and ending along each spatial axis (D1_begin, D2_begin, ..., D1_end, D2_end, ...). Will be set to 0 along each spatial axis if not set. strides (Optional[Union[Tuple[int, ...], List[int]]], optional): stride along each spatial axis. Will be set to 1 along each spatial axis if not set. dilations (Optional[Union[Tuple[int, ...], List[int]]], optional): dilation along each spatial axis. Will be set to 1 along each spatial axis if not set. kernel_shape (Optional[Union[Tuple[int, ...], List[int]]], optional): shape of the convolution kernel. Inferred from input weight if not present group (int, optional): number of groups input channels and output channels are divided into. Defaults to 1.
- `auto_pad` (str, optional): padding strategy. Defaults to "NOTSET".
**Raises:**
- `ValueError`: if arguments are not appropriate
- `TypeError`: unexpected types
- `NotImplementedError`: a convolution that we don't support
**Returns:**
- `Union[np.ndarray, Tracer]`: evaluation result or traced computation