# Typical usage of `digger.utils`

The input and output files for D-Claw are in very specific formats. The functions found in [`digger.utils`](#digger.utils) help support the creation and modification of these files. Functions like [`digger.utils.biplanar`](#digger.utils.biplanar) and [`digger.utils.logspiral`](#digger.utils.logspiral) are used by [`digger.make`](#digger.make) to create hypothetical post-failure surfaces. Some common D-Claw output postprocessing is described below.

## Geospatial file conversion

It may be useful to convert D-Claw ouput into files usable by typical GIS programs. The function [`digger.utils.fgtools.fg2raster`](#digger.utils.fgtools.fg2raster) converts a single element of q stored in a fixed grid file into a geotif. It relies on the clawpack fixed grid backends and can either convert a [fgout-style](https://www.clawpack.org/fgout.html) file or a [fgmax-style](https://www.clawpack.org/fgmax.html) file.

Additionally, [`digger.utils.fgtools.fg2shp`](#digger.utils.fgtools.fg2shp) will contour a single element of q and provide a PolyLine-type shapefile containing these contours.

```{literalinclude} ../../../../../examples/post-run/barry_arm/setpostprocess.py
:start-after: Block 1 Start
:end-before: Block 1 End
```

## Construction of a dtopo file

Sometimes one might want to convert the results of one simulation into a [topography displacement file](https://www.clawpack.org/topo.html#topography-displacement-files) for use in a second simulation. Digger provides a function for this purpose, [`digger.utils.nc2dtopo`](#digger.utils.dtopo.nc2dtopo)


```{literalinclude} ../../../../../examples/post-run/barry_arm/setpostprocess.py
:language: python
:start-after: Block 2 Start
:end-before: Block 2 End
```