Returning vector of values shared across 3 vectors?

try this:
vec1 <- c(4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81)
vec2 <- c (1,2,3,4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66)
vec3 <- c (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,52)
 intersect(vec1,intersect(vec2, vec3))
[1]  4  5  6  7  8  9 10 11 12 52

Help-Rs,

I've got three vectors representing participants:

vec1 <- c(4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81)
vec2 <- c (1,2,3,4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66)
vec3 <- c (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,52)

I'd like to return a vector that contains only the values that are shared across ALL THREE vectors. So the statement would return a vector that looked like this:
4,5,6,7,8,9,10,11,12,52

For some reason I initially thought that a cbind and a unique() would handle it, but then common sense sunk in.? I think the sleep deprivation is starting to take it's toll.? I've got to believe that there is a simple solution to this dilema.

Thanks in adance for any help!
C
? ? ? ?[[alternative HTML version deleted]]

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Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
try this:

vec1<- c(4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81)
vec2<- c (1,2,3,4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66)
vec3<- c (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,52)
  intersect(vec1,intersect(vec2, vec3))
  [1]  4  5  6  7  8  9 10 11 12 52

Or if your real problem may go to more vec's and you don't want to keep 
nesting the calls:

Reduce(intersect, list(vec1, vec2, vec3))
# [1]  4  5  6  7  8  9 10 11 12 52
On Sat, Oct 1, 2011 at 2:00 AM, Chris Conner<connerpharmd at yahoo.com>  wrote:
Help-Rs,

I've got three vectors representing participants:

vec1<- c(4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81)
vec2<- c (1,2,3,4,5,6,7,8,9,10,11,12,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66)
vec3<- c (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,52)

I'd like to return a vector that contains only the values that are shared across ALL THREE vectors. So the statement would return a vector that looked like this:
4,5,6,7,8,9,10,11,12,52

For some reason I initially thought that a cbind and a unique() would handle it, but then common sense sunk in.  I think the sleep deprivation is starting to take it's toll.  I've got to believe that there is a simple solution to this dilema.

Thanks in adance for any help!
C
        [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Brian S. Diggs, PhD
Senior Research Associate, Department of Surgery
Oregon Health & Science University