Indexing Error in _d8_distance_from_ridge #255
Description
The "distance_to_ridge" function produces an off-by-one indexing error for D8 flow routing. For example, the following code triggers the error:
from pysheds.grid import Grid
from math import nan
grid = Grid.from_raster("fdir.tif")
fdir = grid.read_raster("fdir.tif")
weights = grid.read_raster("weights.tif")
assert fdir.shape == weights.shape
# Causes an off-by-one indexing error
grid.distance_to_ridge(
fdir, weights, nodata_out=nan, routing="d8", dirmap=(3, 2, 1, 8, 7, 6, 5, 4)
)
With error stack:
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "path\to\issue.py", line 10, in <module>
grid.distance_to_ridge(
File "path\to\Lib\site-packages\pysheds\sgrid.py", line 1649, in distance_to_ridge
rdist = self._d8_distance_to_ridge(fdir=fdir, weights=weights,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "path\to\Lib\site-packages\pysheds\sgrid.py", line 1676, in _d8_distance_to_ridge
startnodes = startnodes[(indegree == 0)]
~~~~~~~~~~^^^^^^^^^^^^^^^^^
IndexError: boolean index did not match indexed array along dimension 0; dimension is 6205794 but corresponding boolean dimension is 6205763