bug: ParticleData.to_prp() returns global coordinates #2395
Description
Describe the bug
Not sure if this can yet be qualified as bug, or is simply still under active development and I'm a bit early in posting this, but I noticed that ParticleData.to_prp() returns global coordinates. PRT6 currently expects model coordinates for the input. This isn't caught in the tests as as far as I could see, as no PRT6 models are run using a grid with offsets (in both flopy and modflow6 repos).
I saw other options for specifying model coordinates are under review in Modflow6, which might also solve this issue by allowing computation with global coordinates: MODFLOW-ORG/modflow6#1901. Nevertheless, it might be nice to have both global and model coordinate options in to_prp().
EDIT: just noticed issue #2388. If vertices are specified in model coordinates, that would also solve this issue.
To Reproduce
import flopy as fp
import numpy as np
gr = fp.discretization.StructuredGrid(
10 * np.ones(10),
10 * np.ones(10),
top=np.ones((10, 10)),
botm=np.zeros((1, 10, 10)),
nlay=1,
xoff=100,
yoff=300,
)
pd = fp.modpath.ParticleData([(0, 0, 0), (0, 5, 5), (0, 9, 9)], structured=True)
list(pd.to_prp(gr))Expected behavior
Perhaps the option of returning global or model coordinates could be added to to_prp()? Something like the code below could do the trick. I used the term model_coords since in modpath local signifies a location within a cell.
If this is something you would want to support, Id be happy to submit a PR with this small change, let me know!
# class ParticleData:
# ...
def to_coords(self, grid, localz=False, model_coords=True) -> Iterator[tuple]: # <-- add model_coords=True
# ...
def cvt_xy(p, vs):
mn, mx = min(vs), max(vs)
span = mx - mn
return mn + span * p
if grid.grid_type == "structured":
if not hasattr(self.particledata, "k"):
raise ValueError(
"Particle representation is not structured but grid is"
)
def cvt_z(p, k, i, j):
mn, mx = (
grid.botm[k, i, j],
grid.top[i, j] if k == 0 else grid.botm[k - 1, i, j],
)
span = mx - mn
return mn + span * p
def convert(row, model_coords=True) -> tuple[float, float, float]: # <-- add model_coords
verts = grid.get_cell_vertices(row.i, row.j)
if model_coords:
xs, ys = grid.get_local_coords(*np.array(verts).T) # <--convert global coords to model coords
else:
xs, ys = list(zip(*verts))
return [
cvt_xy(row.localx, xs),
cvt_xy(row.localy, ys),
row.localz if localz else cvt_z(row.localz, row.k, row.i, row.j),
]
else:
if hasattr(self.particledata, "k"):
raise ValueError(
"Particle representation is structured but grid is not"
)
def cvt_z(p, nn):
k, j = grid.get_lni([nn])[0]
mn, mx = (
grid.botm[k, j],
grid.top[j] if k == 0 else grid.botm[k - 1, j],
)
span = mx - mn
return mn + span * p
def convert(row, model_coords=True) -> tuple[float, float, float]: # <-- add model_coords
verts = grid.get_cell_vertices(row.node)
if model_coords:
xs, ys = grid.get_local_coords(*np.array(verts).T) # <--convert global coords to model coords
else:
xs, ys = list(zip(*verts))
return [
cvt_xy(row.localx, xs),
cvt_xy(row.localy, ys),
row.localz if localz else cvt_z(row.localz, row.node),
]
for t in self.particledata.itertuples():
yield convert(t, model_coords=model_coords)
def to_prp(self, grid, localz=False, model_coords=True) -> Iterator[tuple]: # <-- add model_coords
# ...
for i, (t, c) in enumerate(
zip(
self.particledata.itertuples(index=False),
self.to_coords(grid, localz, model_coords=model_coords), # <-- pass model_coords
)
):
row = [i] # release point index (irpt)
if "node" in self.particledata:
k, j = grid.get_lni([t.node])[0]
row.extend([(k, j)])
else:
row.extend([t.k, t.i, t.j])
row.extend(c)
yield tuple(row)