NCAR / geocat-applications

GeoCAT Applications is a community resource inspired by the NCL Applications page.
https://ncar.github.io/geocat-applications/
Apache License 2.0
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NCL Entry for Precession Differenes #67

Open cyschneck opened 4 days ago

cyschneck commented 4 days ago

NCL uses a different floating type which impacts precession. Would be useful to make a fully entry about the origin of the precession differences to be able to link to in future entries

For example:

asin: 
    python (math):  0.5235987755982989
    python (numpy): 0.5235987755982989
    ncl:        0.5235988

There are some diffs in the definitions depending upon the context.

In NCL the float type is 32 bits and double 64 bits, whereas in Python the float type is generally a 64-bit floating point number.

This is also slightly different from numpy which has its own types (e.g. np.float64, np.float32).

Generally the 64-bit types are the defaults in Python though, which is different from NCL and something that's come up in the past.

(Originally from #40)