xarray.apply ufunc - Python for climatology, oceanograpy and atmospheric science

xarray.apply ufunc

Official documents

input_core_dims

Core dimensions are automatically moved to the last axes of input variables before applying func

Tips

Rapidly Prototyping High-Performance Meteorological Data Systems Using Xarray and Numba: 99th American Meteorological Society Annual Meeting

Pangeo use case - when dask.array and xarray.apply_ufunc are not the answer

Xarray with Dask Arrays — Custom workflows and automatic parallelization

python xarray - dask performance apply along axis - Stack Overflow

python - What's the difference between dask=parallelized and dask=allowed in xarray's apply_ufunc? - Stack Overflow

Chunking and performance

A good rule of thumb is to create arrays with a minimum chunksize of at least one million elements (e.g., a 1000x1000 matrix).

apply_ufunc(dask='parallelized'): mix of chunked and non-chunked *args results in shape mismatch · Issue '#2817 · pydata/xarray · GitHub

Examples

code:python

sigma0 = xr.apply_ufunc(gsw.sigma0, ds.salt, ds.thetaoga,

dask='parallelized', output_dtypes=ds.salt.dtype)