Fixed incorrect if conditions to check for SCIENCE frames

pycrires/pipeline.py

@@ -1246,7 +1246,7 @@ def run_skycalc(self, pwv: float = 3.5) -> None:
 
         science_index = np.where(self.header_data["DPR.CATG"] == "SCIENCE")[0]
 
-        if len(science_index) > 0:
+        if len(science_index) == 0:
             raise RuntimeError("Cannot run skycalc: there are no SCIENCE frames")
 
         # Requested PWV for observations
@@ -3759,8 +3759,8 @@ def obs_nodding(
         indices = self.header_data["DPR.CATG"] == "SCIENCE"
         science_idx = np.where(indices)[0]
 
-        if len(science_idx) > 0:
-            raise RuntimeError("Cannot run obs_staring: there are no SCIENCE frames")
+        if len(science_idx) == 0:
+            raise RuntimeError("Cannot run obs_nodding: there are no SCIENCE frames")
 
         # Wavelength setting and DIT
         science_wlen = self.header_data["INS.WLEN.ID"][science_idx[0]]
@@ -4307,7 +4307,7 @@ def obs_nodding_irregular(
 
         science_idx = np.where(self.header_data["DPR.CATG"] == "SCIENCE")[0]
 
-        if len(science_idx) > 0:
+        if len(science_idx) == 0:
             raise RuntimeError("Cannot run obs_nodding_irregular: there are no SCIENCE frames")
 
         # Wavelength setting and DIT