Re: [R] sum() returns 0 not NA

2010-04-27 Thread will . eagle
Exactly the same question was asked, in exactly the same words, 5 days ago: https://stat.ethz.ch/pipermail/r-help/2010-April/235337.html Dear all, sorry for reposting. I thought my first mail had been bounced off since I could not find it online and no answers on my email account. Problem

[R] sum() returns 0 not NA

2010-04-20 Thread will . eagle
Dear all, just a stupid R question, since the results puzzle me a bit: sum(c(NA,NA), na.rm=TRUE) [1] 0 NA + NA [1] NA NA + 1 [1] NA Why does sum(c(NA,NA), na.rm=TRUE) return 0 and not NA? Thanks in advance, Will __ R-help@r-project.org

Re: [R] sum() returns 0 not NA

2010-04-20 Thread Gabor Grothendieck
So that the two lines below give the same answer: xx - c(); yy - 1:3 sum(xx) + sum(yy) sum(c(xx, yy)) On Tue, Apr 20, 2010 at 12:42 PM, will.ea...@gmx.net wrote: Dear all, just a stupid R question, since the results puzzle me a bit: sum(c(NA,NA), na.rm=TRUE) [1] 0  NA + NA [1] NA NA

Re: [R] sum() returns 0 not NA

2010-04-20 Thread Joshua Wiley
As a disclaimer, I cannot say that this is why sum() was designed as it was. 0 is the sum of a set with no elements, the empty set {}. When na.rm=TRUE, NA values are removed. When the only values are NA (as in your example c(NA, NA) ), and you remove them all, you are taking the sum of no

Re: [R] sum() returns 0 not NA

2010-04-20 Thread Ted Harding
On 20-Apr-10 17:07:31, Joshua Wiley wrote: As a disclaimer, I cannot say that this is why sum() was designed as it was. 0 is the sum of a set with no elements, the empty set {}. When na.rm=TRUE, NA values are removed. When the only values are NA (as in your example c(NA, NA) ), and you

[R] sum() returns 0 not NA

2010-04-15 Thread Wilmar Igl
Dear all, just a stupid R question, since the results puzzle me a bit: sum(c(NA,NA), na.rm=TRUE) [1] 0 NA + NA [1] NA NA + 1 [1] NA Why does sum(c(NA,NA), na.rm=TRUE) return 0 and not NA? Thanks in advance, Will __ R-help@r-project.org

Re: [R] sum() returns 0 not NA

2010-04-15 Thread Ted Harding
On 15-Apr-10 12:37:42, Wilmar Igl wrote: Dear all, just a stupid R question, since the results puzzle me a bit: sum(c(NA,NA), na.rm=TRUE) [1] 0 NA + NA [1] NA NA + 1 [1] NA Why does sum(c(NA,NA), na.rm=TRUE) return 0 and not NA? Thanks in advance, Will For the same

Re: [R] sum() returns 0 not NA

2010-04-15 Thread David Winsemius
On Apr 15, 2010, at 8:37 AM, Wilmar Igl wrote: Dear all, just a stupid R question, since the results puzzle me a bit: sum(c(NA,NA), na.rm=TRUE) [1] 0 NA + NA [1] NA NA + 1 [1] NA Why does sum(c(NA,NA), na.rm=TRUE) return 0 and not NA? sum(c()) [1] 0 ?sum NB: the sum of an