Pick Channels Dialog

This dialog is shown if you try and load a data file with more than two channels of data.
 
Each channel has an entry in the grid, for which you can pick:
Frequency The frequency channel (there must be only one of these).
Intensity An Intensity channel (there can be one or more of these).
Weights A Weight channel, used as a relative error when contour fitting. There must either be none of these, or one for each intensity channel.
Discard The channel is discarded.