Yes, this looks ideal. Cheers
On 5/29/2012 11:47 AM, Matthew Dowle wrote:
Yes. Now that := by group is implemented in 1.8.1, the next step would
be to make it multiple := by group, which can't be done efficiently by
chaining anyway. So, DT[,{newcol1:=colA+colB newcol2:=newcol1*2
},by=month(colC)] Where the 2nd := can use the result from the first
like that, too. Would that syntax be ok?
Or perhaps an overload on transform that allows {expr}.
Maybe. Kinda getting hooked on := now, though.
Matthew
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