[6547] in s-news-athena
replace -99 by NA
daemon@ATHENA.MIT.EDU (Chang Yu)
Wed Mar 1 20:36:11 1995
Date: Wed, 1 Mar 95 18:40:32 CST
From: "Chang Yu" <chang@muskie.biostat.umn.edu>
To: S-news@utstat.toronto.edu
Cc: chang@muskie.biostat.umn.edu
Hi, Dear all,
It is a simple question. I just could not get it.
Here is part of my data:
> dlsoa.data
pid weight cad no-social male age75-79 age80-84 age85+ low-income stroke
1 1 2128 0 0 0 0 1 0 0 0
2 2 4396 1 0 1 0 0 0 -99 0
5 7 2128 0 0 0 0 1 0 0 0
6 8 2128 0 0 0 0 1 0 1 0
cancer arthritis diabets control status dement3
1 0 1 0 0 1 0
2 0 0 1 1 0 0
5 0 0 1 -99 1 0
6 0 0 0 -99 0 0
In the data file the missing data were coded as -99 and they were read into
a data frame as -99 by function "read.table".
Now I want to replace -99 by NA so tree() function will know it, otherwise
it will work on it as if they are numerical values -99. I tried the argument
"na.strings=" -99"" without any luck. It is the wrong way to do it.
Could anyone give me a hint?
Thanks a lot!
Chang Yu
chang@muskie.biostat.umn.edu
