sum overflow (PR#1091)

Full_Name: Bill Simpson
Version: 1.2.3
OS: linux
Submission from: (NULL) (193.62.250.209)


I think I have found an accuracy problem with sum()

a<-1:1000
b<-1:1000

crossprod(a,a)*crossprod(b,b)

[,1]
[1,] 1.114448e+17

drop(.Last.value)

[1] 1.114448e+17

#this should give same answer as above

sum(a*a)*sum(b*b)

[1] -652010736
#seems to be due to sum using integer representation which overflows instead of
using
#double representation

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