count lines together with summing a specific column - awk

Question

I would very much appreciate if someone can help this task. I am hoping to do this with awk, but if there is better strategy other than awk, I would also like to know.
This is infile,
S,0,3118,*,0,*,*,*,10-2,c645,5
H,0,648,99.2,+,0,0,250I648M2220I,10-2,c4204,1
H,0,597,99.2,+,0,0,314I597M2207I,10-2,c4022,1
S,1,2488,*,0,*,*,*,10-2,c17,4
H,1,798,97.4,+,0,0,1407I798M283I,10-2,c232,2
H,1,796,98,+,0,0,628I796M1064I,10-2,c67,1
H,1,751,97.5,-,0,0,668I144M3D290MD313M1073I,10-2,c115,1
H,1,792,98.4,+,0,0,628I792M1068I,10-2,c380,1
S,2,2437,*,0,*,*,*,10-2,c102,7
S,3,2218,*,0,*,*,*,10-2,c1081,10
H,3,928,99.2,-,0,0,3D925M1293I,10-2,c986,3
the outfile what I would like to have is,
outfile
0,3,7
1,5,9
2,1,7
3,2,13
So, if the second column of infile is same, count the number of lines (second column of the outfile) together summing value of the last column (third column of the outfile).
I tried as
awk -F',' '{a[$2] += $11}; END{for(c in a) print c, a[c]}' < infile
but I do not know how to count the line number together.

Answer 1

Simple Awk command, with logic to hash on the $2 value. Once to track the count of occurrences of the second column value and once for the sum on the last field. It goes like
awk 'BEGIN{FS=OFS=","}{unique[$2]++; uniqueSum[$2]+=$NF}END{for (i in unique) print i,unique[i],uniqueSum[i]}' file
which will get you the output you need. The part BEGIN{FS=OFS=","} takes care of setting the input and output field separators to , and {unique[$2]++; uniqueSum[$2]+=$NF} is for hashing the count of the unique ID value from $2 and its summed up value in last column. the END clause is run after all the lines are processed. So we print the unique column, its count and its total sum to get the output as you need.
0,3,7
1,5,9
2,1,7
3,2,13