fixed bug when first line of df is dropped, added flipped qetbias flag, defaults to true like convention for sweeps

Author: rkromani

pytesdaq/processing/_iv_didv_tools.py

@@ -1831,7 +1831,8 @@ def plot_noise_model(self, idx='all', xlims=(10, 2e5), ylims_current=None,
         )
 
 
-    def get_offsets_dict(self, metadata, channel_name, lgcdiagnostics=False):
+    def get_offsets_dict(self, metadata, channel_name, lgcdiagnostics=False,
+                        lgc_sweepbias_flipped=True):
         """
         Function to get a dictionary of offsets of i0 and ibias used by
         QETpy to calculate the i0, r0, p0, etc. of a given dIdV.
@@ -1845,6 +1846,16 @@ def get_offsets_dict(self, metadata, channel_name, lgcdiagnostics=False):
 
         channel_name: str
             Used to get the right channel out of the metadata
+            
+        lgcdiagnostics: boolean, optional
+            If True, prints out diagnostics
+            
+        lgc_sweepbias_flipped: boolean, optional
+            Defaults to True. If True, assumes that the bias for the IV sweep
+            from which the offset_dict was generated was flipped in polarity
+            (i.e. multiplied by negative one). To contradict this, we just 
+            multiply the ibias_offset by negative one. Defaults to True because
+            this is the default way we process IV sweeps.
 
         Returns
         -------
@@ -1861,14 +1872,26 @@ def get_offsets_dict(self, metadata, channel_name, lgcdiagnostics=False):
         IV_ibias_offset = self.ivobj.ibias_off[0][1]
         IV_ibias_offset_err = self.ivobj.ibias_off_err[0][1]
 
-        rp_measured = self.df['rp'][0]
+        if lgc_sweepbias_flipped:
+            IV_ibias_offset *= -1
+        
+        i = 0
+        rp_measured = None
+        while rp_measured is None:
+            try:
+                rp_measured = self.df['rp'][i]
+            except KeyError:
+                i += 1
+        
+        output_offset = metadata[0]['detector_config'][channel_name]['output_offset']
 
         return_dict = {
             "i0_off": IV_i0_offset,
             "i0_off_err": IV_i0_offset_err,
             "ibias_off": IV_ibias_offset,
             "ibias_off_err": IV_ibias_offset_err,
             "i0_changable_offset": output_offset_during_didv,
+            "output_offset": output_offset,
             "rp": rp_measured,
             "IVobj": self,
         }