# sum

The sum of all the elements of the group, as if chaining + operations.

## sum(T.a : number) 🡒 number, autodiff aggregator

Returns the sum of the numbers of the group.

Example:

table T = with
[| as A, as B |]
[| 0,   "a"   |]
[| 0.5, "a"   |]
[| 0,   "b"   |]
[| 1,   "b"   |]
[| 1,   "c"   |]

table G[gdim] = by T.B

where T.B != "c"
show table "" a1b4 with
gdim
sum(T.A)
group by gdim


The aggregator returns 0 on empty groups.

## sum(T.a : ranvar) 🡒 number, aggregator

Returns the sum of the ranvars of the group.

Example:

table T = with
[| as A, as B |]
[| 0,   "a"   |]
[| 0.5, "a"   |]
[| 0,   "b"   |]
[| 1,   "b"   |]
[| 1,   "c"   |]

T.R = poisson(T.A)

table G[gdim] = by T.B

where T.B != "c"
show table "" a1b4 with
gdim
sum(T.R)
group by gdim


The aggregator returns dirac(0) on empty groups.

## sum(T.a : zedfunc) 🡒 number, aggregator

Returns the sum of the zedfuncs of the group.

Example:

table T = with
[| as A, as B |]
[| 0,   "a"   |]
[| 0.5, "a"   |]
[| 0,   "b"   |]
[| 1,   "b"   |]
[| 1,   "c"   |]

T.R = linear(T.A)

table G[gdim] = by T.B

where T.B != "c"
show table "" a1b4 with
gdim
sum(T.R)
group by gdim


The aggregator returns constant(0) on empty groups.