# Documentation#

Documentation helps others use your code! Please document new contributions. SimPEG tries to follow the numpydoc style of docstrings (check out the style guide). SimPEG then uses sphinx to build the documentation. When documenting a new class or function, please include a description (with math if it solves an equation), inputs, outputs and preferably a small example.

For example:

```
class WeightedLeastSquares(BaseComboRegularization):
r"""Weighted least squares measure on model smallness and smoothness.
L2 regularization with both smallness and smoothness (first order
derivative) contributions.
Parameters
----------
mesh : discretize.base.BaseMesh
The mesh on which the model parameters are defined. This is used
for constructing difference operators for the smoothness terms.
active_cells : array_like of bool or int, optional
List of active cell indices, or a `mesh.n_cells` boolean array
describing active cells.
alpha_s : float, optional
Smallness weight
alpha_x, alpha_y, alpha_z : float or None, optional
First order smoothness weights for the respective dimensions.
`None` implies setting these weights using the `length_scale`
parameters.
alpha_xx, alpha_yy, alpha_zz : float, optional
Second order smoothness weights for the respective dimensions.
length_scale_x, length_scale_y, length_scale_z : float, optional
First order smoothness length scales for the respective dimensions.
mapping : SimPEG.maps.IdentityMap, optional
A mapping to apply to the model before regularization.
reference_model : array_like, optional
reference_model_in_smooth : bool, optional
Whether to include the reference model in the smoothness terms.
weights : None, array_like, or dict or array_like, optional
User defined weights. It is recommended to interact with weights using
the `get_weights`, `set_weights` functionality.
Notes
-----
The function defined here approximates:
.. math::
\phi_m(\mathbf{m}) = \alpha_s \| W_s (\mathbf{m} - \mathbf{m_{ref}} ) \|^2
+ \alpha_x \| W_x \frac{\partial}{\partial x} (\mathbf{m} - \mathbf{m_{ref}} ) \|^2
+ \alpha_y \| W_y \frac{\partial}{\partial y} (\mathbf{m} - \mathbf{m_{ref}} ) \|^2
+ \alpha_z \| W_z \frac{\partial}{\partial z} (\mathbf{m} - \mathbf{m_{ref}} ) \|^2
Note if the key word argument `reference_model_in_smooth` is False, then mref is not
included in the smoothness contribution.
If length scales are used to set the smoothness weights, alphas are respectively set internally using:
>>> alpha_x = (length_scale_x * min(mesh.edge_lengths)) ** 2
"""
```

## Building the documentation#

If you would like to see the documentation changes. In the repo’s root directory, enter the following in your terminal.

```
make all
```

## Serving the documentation locally#

Once the documentation is built. You can view it directly using the following command. This will automatically serve the docs and you can see them in your browser.

```
make serve
```