fix: handle MPC comet data with unparseable orbital elements#401
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mrosseel wants to merge 1 commit intobrickbots:mainfrom
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fix: handle MPC comet data with unparseable orbital elements#401mrosseel wants to merge 1 commit intobrickbots:mainfrom
mrosseel wants to merge 1 commit intobrickbots:mainfrom
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Skyfield's load_comets_dataframe() can return string dtypes for numeric columns when the MPC data file contains rows it can't parse (e.g. the MPEC 2026-F34 batch of 27 historical comets with malformed fields). Even a few bad rows cause pandas to fall back to dtype=object for the entire perihelion_year column, which then crashes comet_orbit() for *every* comet with a numpy UFuncNoLoopError. Fix: force numeric coercion with pd.to_numeric() after loading, drop rows with unparseable essential fields, and add a try/except safety net around individual comet processing. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
load_comets_dataframe()can't parse correctly (e.g. MPEC 2026-F34 added 27 historical comets with malformed fixed-width fields). When even a single row has an unparseableperihelion_year, pandas falls back todtype=objectfor the entire column, turning every year value into a string like'2028'instead of an integer. Skyfield'scomet_orbit()then crashes on every comet withnumpy UFuncNoLoopError: ufunc 'add' did not contain a loop with signature matching types (dtype('<U4'), dtype('float64')).pd.to_numeric(errors="coerce")on all orbital element columns after loading to ensure proper numeric dtypes regardless of bad rowsTest plan
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