Message-ID: <401BD054.5030001@optonline.net>
Date: 2004-01-31T15:57:08Z
From: Chuck Cleland
Subject: in which column is an entry?
In-Reply-To: <200401311643.16719.ozric@web.de>
Christian Schulz wrote:
> df is a data.frame with 43 colums and 29877 rows with lot of NA.
> I want the column number for all respondendts in one column
> where is the first entry >=0 as columnnumber.
>
> my first step:
> time <- function(df)
> + { for (i in 1:length(df [,1])) {
> + which(df[i,1]:df[i,43] >= 0)
> + }
> + }
>
>
>>t1 <- time(YS)
>
> Error in df[i, 1]:df[i, 43] : NA/NaN argument
I am not sure, but I think you might want something like this:
t1 <- apply(df, 1, function(x){
ifelse(all(is.na(x)) | all(na.omit(x) < 0),
NA, which(x >= 0))})
hope this helps,
Chuck Cleland
--
Chuck Cleland, Ph.D.
NDRI, Inc.
71 West 23rd Street, 8th floor
New York, NY 10010
tel: (212) 845-4495 (Tu, Th)
tel: (732) 452-1424 (M, W, F)
fax: (917) 438-0894