circuitscape / spatialgraphs-old

Archive of early development of SpatialGraphs.jl -- preserved because it is a dependency for other work

SpatialGraphs.jl

Build Status

Functions to create graphs from gridded geospatial data to enable things like least cost path and corridor analysis as well as other graph metrics.

spatialgraphs-old's Issues

Allow for multiple connected components in a nodemap

Need to make sure that functions work as expected in cases when a nodemap has separate connected components. Add a corresponding test.

Add new graph type (compatible with LightGraphs) with additional geospatial fields?

Add either lat/lon coordinates for vertices, or entire geometries, as well as info on projections? Not sure what this should look like.

Maybe something like this:

mutable struct SpatialWeightedGraph
    graph::AbstractSimpleWeightedGraph
    geometries::Vector{AbstractGeometry}
end

This would enable easy mapping of of paths or cost distances to geographic space/geometries.

Then add methods for all of the LightGraphs/SimpleWeightedGraphs functions, e.g.:

has_edge(a::SpatialWeightedGraph, b, c) = has_edge(a.graph, b, c)

The alternative is for the user to store this information elsewhere and make sure it remains properly sorted. That asks more of the user and may introduce more opportunities for user error.

Allow a graph vertex to take up more than one pixel

Right now, an underlying assumption is for each pixel in a raster to be a unique graph vertex, but this may not fit all use cases. Allow a single vertex to "occupy" multiple raster pixels in geographic space.

The lift shouldn't be too hard, but need to test that it works, particularly in converting paths or pathstates back to rasters.

Another consideration would be converting paths to lines. Right now path(s)_to_linestring(s) require a nodemap with unique node indices for every pixel. Maybe these functions just aren't offered in this case.

NaNs in GeoArrays break functions

Need to make graph construction functions for GeoArrays ignore NaNs in addition to missingval

Add docstrings for exported functions

src/graphs.jl

• construct_nodemap
• construct_graph

src/paths.jl

• least_cost_path
• least_cost_path
• path_to_array
• path_to_cartesian_coords
• random_lcps
• pathstate_to_array
• pathstate_to_geoarray
• path_to_linestring
• paths_to_linestrings
• path_to_array
• path_to_geoarray