On Jan 17, 2010, at 11:00 AM, Andreas Wittmann wrote:
Dear R-users,
i have a simple problem maybe, but i don't see the solution. i want
to find the entry-wise closest element of an vector compared with
another.
ind1<-c(1,4,10)
ind2<-c(3,5,11)
for (i in length(ind2):1)
{
print(which.min(abs(ind1-ind2[i])))
}
for ind2[3] it should be ind1[3] 10, for ind2[2] it should be ind1[2]
4 and for ind2[1] it should be ind1[1] 1. but with the for-loop above
i get ind1[3], ind1[2] and ind1[2].
any suggestions are quite welcome.
You are failing to use the indices that which.min is providing. (And I
think the closest in ind1 to ind2[1] is not 1, but rather 4, so see if
this looks more responsive to your expectations:
for (i in length(ind2):1)
+ {
+ print( ind1[which.min(abs(ind1-ind2[i]))] )
+ }
[1] 10
[1] 4
[1] 4