Unable to generate consistent resolution

[dluks]

I'm trying to create an ideal synthetic placeholder dataset to use as a target for reprojecting some real datasets using reproject_match. I'm not sure if this is a bug or simply user error/misunderstanding, but it's giving me a minor headache. As much as I try to eliminate float-precision errors with rounding and an even division of the desired resolution into the coordinates, I can't seem to escape them when inspecting them using dataset.rio.resolution().

import numpy as np
import rioxarray as riox
import xarray as xr

# Make an empty dataset with the new extent and resolution
# Define the global extent
xmin, ymin, xmax, ymax = (-180.0, -90.0, 180.0, 90.0)

# Calculate the number of rows and columns based on the desired resolution
res = 0.01
nrows = int((ymax - ymin) / res)
ncols = int((xmax - xmin) / res)

# Generate lat (y) and lon (x) grid and round values to two decimal places
y = np.round(np.linspace(ymax, ymin, nrows), 2)
x = np.round(np.linspace(xmin, xmax, ncols), 2)

# Create the empty DataArray with the desired dimensions and fill with ones
target_grid = xr.DataArray(
    data=np.ones((nrows, ncols)),
    dims=("y", "x"),
    coords={
        "y": y,
        "x": x,
    },
)
target_grid.rio.write_crs("EPSG:4326", inplace=True)

Problem description

Despite doing everything in my power to create a clean grid uncontaminated with float-precision errors, the resulting resolution still comes out imperfect (I would have expected a simple (0.01, -0.01)):

target_grid.rio.resolution()  # (0.010000277785494041, -0.010000555586421468)

Environment Information

rioxarray (0.14.0) deps:
  rasterio: 1.3.7
    xarray: 2023.7.0
      GDAL: 3.7.0
      GEOS: 3.11.2
      PROJ: 9.2.1
 PROJ DATA: /home/lusk/mambaforge/envs/traits/share/proj
 GDAL DATA: /home/lusk/mambaforge/envs/traits/share/gdal

Other python deps:
     scipy: 1.10.1
    pyproj: 3.6.0

System:
    python: 3.9.16 | packaged by conda-forge | (main, Feb  1 2023, 21:39:03)  [GCC 11.3.0]
executable: /home/lusk/mambaforge/envs/traits/bin/python
   machine: Linux-5.13.0-27-generic-x86_64-with-glibc2.31

[snowman2]

When generating coordinates, it is important to remember that the coordinates represent the center of the grid cell. That means you have to adjust by resolution/2 from the outer bounds.

[dluks]

🤦‍♂️ Of course. I had a feeling it was user error. That solved the issue. Thanks!