I have go through the forum but did not see this question. Hope I don't miss it.
I want to add a new colum "C" to a dataset with existing columns named "A" and "B". The value of "C" shall be the difference between the value of "A" at the same row and the previous value of "A". (A[[i]]-A[[i-1]]) I see how to do it with creating a new list for "C" and append it to the dataset but is it possible to do it using slots #. Thanks for your help.