> CLI for parsing Ordnance Survey Digital Elevation Model files
This is the CLI for the sister [`terrain50`](https://www.npmjs.com/package/terrain50) library on npm for parsing Ordnance Survey DEM files I also implemented.
- **Current version:** 
The command-line interface works on a subcommand-based system using [`applause-cli`](https://npmjs.org/packages/applause-cli) (another package of mine).
Display the usage information like this:
```bash
terrain50 --help
```
If you installed it locally, you'll need to do this:
Additionally, a number of environment variables are supported.
Variable | Purpose
------------|-----------------------------
`NO_COLOR` | Disables ANSI escape codes in output (i.e. coloured output). Not recommended unless you have a reason.
`QUIET` | Suppress all output except for warnings and errors (not fully supported everywhere yet)
## Notes
### `image` subcommand: `--boundaries` argument
This argument's purpose is the divide the incoming data into categories so that an AI can be potentially trained on the data (e.g. water depth data, as I'm using). It takes a comma separated list of values like this:
```
0.1,0.5,1,5
```
...and turns it into a number of bins like so:
- -Infinity ≤ value <0.1
- 0.1 ≤ value <0.5
- 0.5 ≤ value <1
- 1 ≤ value <5
- 5 ≤ value <Infinity
Each bin is assigned a colour. Then, for each value in the input, it draws the colour that's assigned to the bin that the value fits into.
