Core Objects

The model, its receptors, the simulations it runs, and their outputs.

Project interface

Model

A STILT project: receptors, settings, and the simulations they define.

Receptor objects

Receptor	Base class for receptors.
PointReceptor	Receptor that releases particles from one point.
ColumnReceptor	Receptor that releases particles evenly along a vertical line.
MultiPointReceptor	Receptor that releases particles from several points at once.
ReceptorID	Identifier of a receptor, "<YYYYMMDDHHMM>_<location_id>".
LocationID	Identifier of a receptor's location.
read_receptors	Read receptors from a CSV file.

Simulation objects

Simulation	One receptor run under one variant.
SimID	Id of one simulation, a (receptor, variant) pair.
Trajectories	Particle trajectories from one HYSPLIT run.
Footprint	Gridded footprint of one receptor.

Collections

model.simulations is a SimulationCollection of every receptor under every variant. sel() narrows it. .trajectories and .footprint give an OutputCollection for loading one kind of output.

SimulationCollection	An ordered selection of a model's simulations.
OutputCollection	One output, trajectory or footprint, across a selection of simulations.
ReceptorCollection	A model's receptors, by position or by receptor id.

Spatial geometries

The cells Footprint.aggregate() sums a footprint into, such as polygons, hexagons, windows around point sources, or groups of grid cells. A Grid works as well. It is documented under Configuration.

Mesh	Polygon cells with ids, the most general geometry.
Zones	Regions made by merging the cells of a Grid or Mesh.
Geometry	Represent a PEP 604 union type
SpatialTarget	Represent a PEP 604 union type

stilt.geometry also has the helpers that compute how much of each footprint cell falls in each target cell. These overlap weights are cached, so each geometry’s weights are computed once per footprint grid.

geometry.overlap_weights	Return the fraction of each raster cell inside each geometry cell.
geometry.check_resolution	Warn when the raster is too coarse to resolve the smallest target cell.
geometry.same_crs	Return whether two CRS strings describe the same CRS, however they are spelled.
geometry.is_longlat_crs	Return whether crs is geographic (longitude/latitude degrees).

Flux fields

stilt.flux looks up a surface flux field under a footprint (used by Footprint.enhancement()) or along particle paths.

flux.sample_flux	Return the flux at each point, or zero outside the field.
flux.sample_field	Return the field's value in the cell nearest each point.
flux.vertical_dim	Return the name of a field's vertical dimension.
flux.particle_enhancement	Return each particle's enhancement, foot times flux summed along its trajectory.
flux.horizontal_dims	Return the names of the horizontal dimensions, (y_dim, x_dim).
flux.nearest_cell	Return the index of the cell nearest each value, or -1 outside the cells.