Poly fit fix

CHANGELOG.md

@@ -24,6 +24,7 @@ This changelog starts with version 2.0.0. Basically all parts of the system, inc
 - fixed failing translation of `dfilter`-defaults
 - fixed unbound recursion error when interpolating with order-independent methods in `interpolateIndex`
 - fixed not working min_periods condition if `window=None` in `assignZScore`
+- fixed Exception occuring when fitting polynomials via `polyfit` to harmonized data, containing all-NaN gaps wider than the polynomial fitting window size.
 
 ## [2.1.0](https://git.ufz.de/rdm-software/saqc/-/tags/v2.0.1) - 2022-06-14
 [List of commits](https://git.ufz.de/rdm-software/saqc/-/compare/v2.0.1...v2.1.0)

saqc/lib/ts_operators.py

@@ -558,6 +558,8 @@ def polyRoller(in_slice, miss_marker, val_range, center_index, poly_deg):
     miss_mask = in_slice == miss_marker
     x_data = val_range[~miss_mask]
     y_data = in_slice[~miss_mask]
+    if len(x_data) == 0:
+        return np.nan
     fitted = poly.polyfit(x=x_data, y=y_data, deg=poly_deg)
     return poly.polyval(center_index, fitted)