playing with data II

[reverse]

q1- how can i get c4 where c4 will always be difference of values in c3 against first of c2 - next of c2
for example .. here c4 for A = 76-7 .. 7-6 ... 6-677.. and so on

Please guide.

c1  c2  c3
A   1   76
A   2   7
A   3   6
A   4   677
B   1   65
B   2   675
B   3   90
B   4   78
C   1   121
C   2   56
C   3   54
C   4   67
D   1   56
D   2   6
D   3   5
D   4   657

[reverse]

@Vijeta please guide.

[Vijeta]

@reverse Try this

<your query> | sort c1,c2|streamstats list(c3) as list , count as count by c1| eval diff  = mvindex(list, count-2)| eval c4= c3 - diff