[R] Syntax Question

[Roger D. Peng]

I'm not sure I fully understand your problem, but maybe something like:

d <- strsplit(st, ",")
index <- sapply(d, function(x) x[[1]]) == "KGEG"
latitude <- sapply(d[index], function(x) x[[4]])

-roger

Clint Bowman wrote:
> I have a large data structure that looks like:
> 
> 
>>strsplit(st,",")[14395]
> 
>  [1] "KGEG"
>  [2] "SA => KGEG"
>  [3] "72785"
>  [4] "47.62139"
>  [5] "-117.52778"
>  [6] "723"
>  [7] "WA"
>  [8] "US"
>  [9] "2"
> [10] "SPOKANE SPOKANE INTERNATIONAL AIRPORT"
> [11] "1"
> 
> 
> I'd like to be able to retrieve, for example, the latitude 
> as.numeric(strsplit(st,",")[[14395]][4]) and longitude 
> as.numeric(strsplit(st,",")[[14395]][5]) for the entry in the structure 
> where strsplit(st,",")[[14395]][5])=="KGEG" by specifying various station 
> IDs.  That is, if I had a simpler structure I could formulate a 
> logical index which would have something along the lines of 
> as.numeric(st[st[1]=="KSEA"][4]) and it would return 47.62139.
> 
> Somewhere I'm getting all bollixed up with the indexing and keep getting 
> sytax errors.  As you can see, the list is quite long (20K+) and I don't 
> wish to have to look up each coordinate by hand.
> 
> TIA
> 
> Clint
>