R help - Feb 2012 - remove NAs from list collectively

Hi,

I am importing dataframe from an Excel file (xlsx package).
The columns contain acutally measurements for single species and
the column-length is of variable. As it is imported as a dataframe the
difference to the "longest" column is filled with NA.
To explain it with an example, my dataframe looks like:

A <- seq(1:10)
B <- c(seq(1:5),rep(NA,5))
C <- c(seq(1:7),rep(NA,3))

df <- data.frame(A,B,C)


Now I'd like to transform that to a list of vectors of different length.
Therefore I need to remove the NAs collectively from the single columns...I
tried for transforming:

as.list(df)

...but I don't know how can I remove the NAs now? as.list doesn't take
na.rm=TRUE argument. Is there any ready function to perform such tasks?
Or is there a better way then to assign the data to a list of vectors with
variable length?

/johannes
--

Two possibilities are:

lapply(df, function (x) x[!is.na(x)])

and

lapply(df, na.exclude)


I hope it helps.

Best,
Dimitris


On 2/8/2012 11:54 AM, Johannes Radinger wrote:
> Hi,
>
> I am importing dataframe from an Excel file (xlsx package).
> The columns contain acutally measurements for single species and
> the column-length is of variable. As it is imported as a dataframe the
difference to the "longest" column is filled with NA.
> To explain it with an example, my dataframe looks like:
>
> A<- seq(1:10)
> B<- c(seq(1:5),rep(NA,5))
> C<- c(seq(1:7),rep(NA,3))
>
> df<- data.frame(A,B,C)
>
>
> Now I'd like to transform that to a list of vectors of different
length. Therefore I need to remove the NAs collectively from the single
columns...I tried for transforming:
>
> as.list(df)
>
> ...but I don't know how can I remove the NAs now? as.list doesn't
take na.rm=TRUE argument. Is there any ready function to perform such tasks?
> Or is there a better way then to assign the data to a list of vectors with
variable length?
>
> /johannes
> --
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/biostatistiek/

Hi,
I want to "melt" my list and get certain deskriptive factors (length
of a vector etc.) into a dataframe. Best to describe it with an example:

A <- seq(4)
B <- seq(6)
C <- seq(9)

ls <- list(A,B,C) # this is my list with vectors of different length

# thats the dataframe how it should look like:
name	length(x)	length(x[x>5])	length(x[x<5])	
A	4	0	4
B	6	1	4
C	9	4	4

How can that be achieved?


/johannes
--