generate the `FuelMap.nc` file

The objective of this part is to easily create a fuel file for a Méso-NH/Blaze run. This file is always named FuelMap.nc. It needs to contain a 2D map on the fire grid for the following fields :

fuel type,
every fuel property that are compliant with the selected rate of spead parameterization in the Méso-NH/Blaze namelist,
ignition time,
walking ignition time.

pyrolib.fuelmap provides tools for the generation of every Fuelmap.nc component. Some Méso-NH files are needed to complete the process. A typical Méso-NH run directory should look like

run_MNH/
├─ EXSEG1.nam
├─ Init_file.des
├─ Init_file.nc

Some Méso-NH files are included in the example directory to run examples.

simplecase.py example provides basic steps to create a fuel map using pyrolib tools. Some operations can be accelerated with numba. pyrolib can check if numba is installed in your environment. If not, pyrolib will show a warning message. In this example, the Méso-NH domain is $(Nx, Ny) = (20, 20)$ with $\Delta_x = \Delta_y = 25$m. The fire mesh is refined with $\Gamma_x = \Gamma_y = 5$. The goal of this example is to set:

a rectangle burnable area defined by $50 \leqslant x \leqslant 450$ and $50 \leqslant y \leqslant 450$,
an ignition patch is set at $t = 10$s with $100 \leqslant x \leqslant 105$ and $245 \leqslant y \leqslant 255$.

As the rate of spread model defined in the Méso-NH namelist, the BalbiFuel class shall be used to define the fuel properties.

"""simplecase.py

Use an existing fuel database and create a simple fuelmap
"""
from pyrolib.fuelmap import FuelDatabase, FuelMap

# create fuel db
my_db = FuelDatabase()

# load existing database
my_db.load_fuel_database("FireFluxI")

# create a FuelMap
my_fuelmap = FuelMap(fuel_db=my_db)

# add a fuel patch of the tall grass fuel from the FireFluxI database
## to show the available fuel keys of the database, use print(my_db)
my_fuelmap.add_fuel_rectangle_patch(xpos=[50, 450], ypos=[50, 450], fuel_key="FireFluxI_tall_grass")

# add a ignition patch
my_fuelmap.add_ignition_rectangle_patch(xpos=[100, 105], ypos=[245, 255], ignition_time=10)

# dump for mesonh
my_fuelmap.dump_mesonh()

After running the script, the directory should contains:

example/
├─ EXSEG1.nam
├─ FuelMap.des
├─ FuelMap.nc
├─ FuelMap2d.nc
├─ Init_file.des
├─ Init_file.nc
├─ simplecase.py

FuelMap2d.nc is an optional file that is easier for human to chack if the generated fuel map respects the requirements.

generate the FuelMap.nc file

generate the `FuelMap.nc` file