Hi,
I have the following datasets:
x=data I am looking through
key=a set of data with the codes I want
I have the following issue:
I want the subset of x which has a code contained in the key dataset. That is,
if x[i] is contained in the key dataset, I want to keep it. Note that x may
contain multiple of the same codes (or obviously none of that code as well)
I currently use two for-loops thusly in my R-code:
k=1
y=data.frame(1,stringsAsFactors=FALSE)
for(i in 1:length(x)){
for(j in 1:length(key)){
if(x[i]==key[j]){
y[k]=x[i]
k=k+1;
}
}
}
However, my dataset (x in this example) is pretty large, so I want to avoid
using two for-loops. Does anybody know an easier way to approach this?
Thanks
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