Index: /issm/trunk-jpl/src/m/plot/processdata.py
===================================================================
--- /issm/trunk-jpl/src/m/plot/processdata.py	(revision 17695)
+++ /issm/trunk-jpl/src/m/plot/processdata.py	(revision 17696)
@@ -29,4 +29,6 @@
 		numberofelements2d=npy.nan
 
+	procdata=npy.copy(data)
+
 	#process patch
 
@@ -35,14 +37,14 @@
 
 	#get datasize
-	if npy.ndim(data)==1:
-		datasize=npy.array([len(data),1])
+	if npy.ndim(procdata)==1:
+		datasize=npy.array([len(procdata),1])
 	else:
-		datasize=npy.shape(data)
+		datasize=npy.shape(procdata)
 	
 	#process NaN's if any
-	nanfill=options.getfieldvalue('nan',-999)
-	if npy.any(npy.isnan(data)):
-		data[npy.isnan(data)]=nanfill
-		print "WARNING: nan's treated as -999 by default.  Change using pairoption 'nan',nan_fill_value in plotmodel call"
+	nanfill=options.getfieldvalue('nan',-9999)
+	if npy.any(npy.isnan(procdata)):
+		procdata[npy.isnan(procdata)]=nanfill
+		print "WARNING: nan's treated as -9999 by default.  Change using pairoption 'nan',nan_fill_value in plotmodel call"
 
 	#non-patch processing 
@@ -72,6 +74,6 @@
 
 	#convert rank-2 array to rank-1
-	if npy.ndim(data)==2 and npy.shape(data)[1]==1:
-		data=data.reshape(-1,)
+	if npy.ndim(procdata)==2 and npy.shape(procdata)[1]==1:
+		procdata=procdata.reshape(-1,)
 
 	#if datatype is still zero, error out
@@ -79,3 +81,3 @@
 		raise ValueError("processdata error: data provided not recognized or not supported")
 	else:
-		return data, datatype
+		return procdata, datatype