extract data from an array without using loop in R
- by Manolo
I have a vector v with row positions:
v<-c(10,3,100,50,...)
with those positions I want to extract elements of a matrix, having a column fixed, for example lets suppose my column number is 2, so I am doing:
data<-c()
data<-c(matrix[[v]][[2]])
matrix has the data in the following format:
[[34]]
[1] "200_s_at" "4853" "1910" "3554" "2658"
So for example, I want to extract from the row 342 the value 1910 only, column 2, and do the same with the next rows
but I got an error when I want to do that, is it possible to do it directly? or should I have a loop that read one by one the positions in v and fill the data vector like:
#algorithm
for i<-1 to length(v)
pos<-v[i]
data[[i]]<-c(matriz[[pos]][[2]])
next i
Thanks
