Added a new function to create a variable inside a file without adding any data

Changed the default FillValue for characters from 'x' to '!' as 'x' was used in site names for NOAA (oxk)

da/tools/io4.py

@@ -269,6 +269,38 @@ class CT_CDF(netCDF4.Dataset):
 
         return False
 
+    def AddVariable(self,datadict,silent=True):
+        """ add variables to file, but no data"""
+        import numpy as np
+
+        existing_vars=self.variables
+
+        if existing_vars.has_key(datadict['name']):
+            return
+        else:
+            if not silent: print 'Creating new dataset: '+datadict['name']
+
+            if datadict.has_key('dtype'):
+                if datadict['dtype'] == 'int':
+                    var = self.createVariable(datadict['name'],'i4',datadict['dims'])
+                elif datadict['dtype'] == 'int64':
+                    var = self.createVariable(datadict['name'],'i8',datadict['dims'])
+                elif datadict['dtype'] == 'char':
+                    var = self.createVariable(datadict['name'],'S1',datadict['dims'],fill_value='!')
+                elif datadict['dtype'] == 'float':
+                    var = self.createVariable(datadict['name'],'f4',datadict['dims'])
+                elif datadict['dtype'] == 'double':
+                    var = self.createVariable(datadict['name'],'f8',datadict['dims'])
+                else:
+                    var = self.createVariable(datadict['name'],'f8',datadict['dims'])
+            else:
+                var = self.createVariable(datadict['name'],'f4',datadict['dims'])
+
+            for k,v in datadict.iteritems(): 
+                if k not in ['name','dims','values','_FillValue','count']: 
+                    var.setncattr(k,v)
+
+
     def AddData(self,datadict,nsets=1,silent=True):
         """ add fields to file, at end of unlimited dimension"""
         import numpy as np
@@ -310,7 +342,7 @@ class CT_CDF(netCDF4.Dataset):
                 elif datadict['dtype'] == 'int64':
                     var = self.createVariable(datadict['name'],'i8',datadict['dims'])#,fill_value=datadict['_FillValue'])
                 elif datadict['dtype'] == 'char':
-                    var = self.createVariable(datadict['name'],'S1',datadict['dims'],fill_value='x')
+                    var = self.createVariable(datadict['name'],'S1',datadict['dims'],fill_value='!')
                 elif datadict['dtype'] == 'float':
                     var = self.createVariable(datadict['name'],'f4',datadict['dims'])#,fill_value=datadict['_FillValue'])
                 elif datadict['dtype'] == 'double':