Fix exception when missing mixing_region or burning_region from histo…

…ry data

README.md

@@ -135,7 +135,14 @@ p.plotHR(m)
 
 [More on Kippenhan plots](docs/kipp.md)
 
-Kippenhan plot with model number vs mass
+Kippenhan plot with model number vs mass. Note all Kippenhan plots
+require your history file to have both mixing_regions X and burning_regions Y
+set in your history_columns.list file, where X and Y are integers that 
+specify the maximum number of mixing/burning
+zones in your model, values around 20 will usually suffice. Models going to
+core collapse may want to increase this limit to 40.
+
+
 ````python
 import mesaPlot as mp
 m=mp.MESA()

mesaPlot/plot.py

@@ -2159,7 +2159,7 @@ def _rebinKipqDataNoModInd(self,m,qtype,z,y):
 		try:
 			x = m.hist.data[qtop+"1"]
 		except ValueError:
-			raise("No field "+qtop+"* found, add mixing_regions 40 and burning_regions 40 to your history_columns.list")
+			raise KeyError("No field "+qtop+"* found, add mixing_regions 40 and burning_regions 40 to your history_columns.list")
 
 
 		numBurnZones=int([xx.split('_')[2] for xx in m.hist.data.dtype.names if qtop in xx][-1])
@@ -2182,7 +2182,7 @@ def _rebinKipqDataWithModInd(self,m,qtype,z,y,modInd):
 		try:
 			x = m.hist.data[qtop+"1"]
 		except ValueError:
-			raise("No field "+qtop+"* found, add mixing_regions 40 and burning_regions 40 to your history_columns.list")
+			raise KeyError("No field "+qtop+"* found, add mixing_regions 40 and burning_regions 40 to your history_columns.list")
 
 
 		numBurnZones=int([xx.split('_')[2] for xx in m.hist.data.dtype.names if qtop in xx][-1])