Hi all, I've been discussing with Hilary the best way to allow ProfilePlot to work with profile data loaded from disk. It seems it would be easy enough to make a Profile object from loaded data, but the holdup is that there are a number of calls to data_source._determine_fields for simple things like checking if a field is log or linear. I had a look at this function, which hangs off of YTDataContainer, and noticed that it doesn't seem to really need the data container itself. I'm thinking that this function could be moved to instead hang off of the Dataset object without a problem. If so, then ProfilePlot could much more easily be extended to work with data from disk, since you could also supply None for the data_source. Does anyone see a problem with doing this? Britton