Error report for stackstac

stackstac-xy_coords-error-report.ipynb

stackstac-xy_coords-error-report.py

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# %%
# %matplotlib inline

import json

import numpy as np
import rioxarray
import stackstac
from matplotlib import pyplot as plt

item = json.load(open("test-tl-stac.geojson", "rt"))
xx = stackstac.stack(
    [item], dtype="float32", bounds_latlon=(-180, -90, 180, +90), xy_coords="topleft"
)
yy = stackstac.stack(
    [item], dtype="float32", bounds_latlon=(-180, -90, 180, +90), xy_coords="center"
)

# %% [markdown]
# ## Check pixel data is the same
#
# We expect image data to be identical between the two modes

# %%
assert (xx.data == yy.data).all().compute()

# %%
fig, axs = plt.subplots(2, 1, figsize=(8, 7))
for idx in range(2):
    xx.isel(band=idx).isel(time=0).plot.imshow(ax=axs[idx])

# %% [markdown]
# ## Check Coordinates
#
# Data spans whole globe in `EPSG:4326` projection with 1 degree pixels.

# %%
_, _, NY, NX = xx.shape
expect_x_left = np.linspace(-180, 180, NX + 1)[:-1]  # -180   -> +179
expect_x_center = expect_x_left + 0.5  # -179.5 -> 179.5

expect_y_left = np.linspace(90, -90, NY + 1)[:-1]  #  +90   -> -89
expect_y_center = expect_y_left - 0.5  #   89.5 -> -89.5

# %% [markdown]
# ### Check topleft
#
# Top-left coordinates are done correctly

# %%
np.testing.assert_allclose(xx.x, expect_x_left)
np.testing.assert_allclose(xx.y, expect_y_left)

# %% [markdown]
# ### Check center
#
# Y coordinate is incorrectly computed when `xy_coord="center"`. As a result `rioxarray` reports incorrect transform and bounds.

# %%
(yy.rio.transform(), yy.attrs["transform"], yy.rio.bounds(), yy.attrs["spec"].bounds)

# %%
np.testing.assert_allclose(yy.x, expect_x_center)

# %%
np.testing.assert_allclose(yy.y, expect_y_center)

# %% [markdown]
# -------------------------------------

test-tl-stac.geojson

test-tl-xband.tif

test-tl-yband.tif