# `make.slabs`

[`make.slabs`](#digger.make.slabs) will generate D-Claw input files that specify an initial 3D landslide geometry from user-supplied files and parameters. [`make.slabs`](#digger.make.slabs)  differs from [`make.scoops`](#digger.make.scoops) in that it will generate landslide source regions with a uniform depth over a user-provided polygon rather than spatially-variable depth based on logarithmic spirals. Optionally, the depth at the edges of the polygon may smoothly transition to zero rather than the default, abrupt transition. The typical usage for [`make.slabs`](#digger.make.slabs) is very similar to the [typical usage for `make.scoop`](scoops.md).

1. Prepare a topography file as a geotif. If the area of interest includes submarine regions, the topography and bathymetry should be represented as a seamless surface in a single file.
2. Prepare or obtain a shapefile containing one or more polygons indicating landslide extents. Ensure that the geotif and shapefile have the same coordinate system.
3. Run [`make.slabs`](#digger.make.slabs) to generate input files for D-Claw. Inspect the output and adjust any input parameters as needed.
4. Using these files, set up a D-Claw simulation to run and analyze. `digger` will not do this for you.

A code snippet that uses [`make.slabs`](#digger.make.slabs) may be found in the file `digger/examples/pre-run/schultz_fire/make_slabs_polygon_h.py`,

```{literalinclude} ../../../../../examples/pre-run/schultz_fire/make_slabs_polygon_h.py
:language: python
```
:::{attention}
This code snippet is not fully self-sufficient. To reproduce the example, execute the code such that the relative path is correct. This may be done by executing the example script from within the directory in which it is located.
:::

After this code runs, it will produce geotif and [topotype3](https://www.clawpack.org/topo.html) files that specify the upper and lower surfaces of the landslide and the initial solid-volume fraction of the landslide material.

It will also create diagnostic figures to assist the user.

```{figure} ../../../../_static/from_examples/slab_source_schultz_polygon_h.png
:alt: Example digger.make.slabs summary figure.

An example of the diagnostic output provided by digger.make.slabs.
```