​Hi Matthew​,

Thanks for the response. None of "px", "pdx", "py", and "pdy" work for me. I perused the code a bit and it's not entirely clear why they don't. The data_source for the frb in my case is a slice, as I showed and that slice object does apparently have those fields defined -- for example doing px = slc['px'] works, though of course the result is a 1D array of values. It seems to be related to the _determine_fields method of the data_source (slice) which rather than returning a tuple, in this case returns a string. In any case, I don't really have time right now to look into it any further.

Jon

On Tue, Apr 26, 2016 at 1:53 PM, yt-users-request@lists.spacepope.org wrote:

Hi Jon,

This is expected behavior, but it probably isn't what you're looking for. dx and dr will be the "pixelized" values of those from the simulation, so they will reflect the cells that went into creating the FRB, rather than the values as they would be computed in the FRB itself. I think what you may be looking for may be accessible in the "px" "pdx" "py" and "pdy" fields, which refer to "in the pixel plane" and which will be with respect to the FRB.