select part of files from a list.files
Hi Jeff,
Does this work okay for you?
ST <- list(data.frame(a=1:10),
data.frame(b=c(NA,NA,NA,NA,NA,6:10)),
data.frame(c=c(1,NA,NA,4:10)),
data.frame(d=c(NA,NA,NA,NA,NA,NA,NA,NA,NA,NA)),
data.frame(e=c(1,2,3,4,NA,NA,7:9,NA)))
doit <- function(data, rows, minpresent) {
if (sum(!is.na(data[rows, ])) >= minpresent) {
data
} else {NULL}
}
results <- lapply(ST, doit, rows = 1:5, minpresent = 2)
## print results
results
in your actual case, you would change to rows = 1:9000 and minpresent
= 1000. You will have a list where each element is a dataset, and if
the dataset does not meet requirements, the element is NULL.
Hope this helps,
Josh
On Mon, May 21, 2012 at 8:32 AM, jeff6868
<geoffrey_klein at etu.u-bourgogne.fr> wrote:
Hi everyone. I'm working on a list of files (about 50 files). I've listed them thanks to the function: list.files. Each of my files contains 35000 lines of data. These files may also contain some missing values NA (sometimes till 10 000 NAs following each other). The aim is to do some correlation matrices between these files (I already have the script). But as I have often missing values, the script doesn't work yet for all my files. In this topic, I would like to select a part of the data of these files before the correlation. In the files list I've created, I would like to select only the 9000 first lines of each of my files: myfiles[1:9000,1], and then, in these 9000 lines, I would like to keep only in my list the files which contains at least 1000 non-NA lines (so numeric data) on my 9000 lines. I would like then to apply my script on this list of files which contains at least 1000 numeric data on the first 9000 lines of my whole data. I've created easy data.frames for the example, if someone could explain me how I can do this easily (at least 2 non NA values for the 5 first lines for example for these fake data.frames just here). Thank you very much! ST1 <- data.frame(a=1:10) ST2 <- data.frame(b=c(NA,NA,NA,NA,NA,6:10)) ST3 <- data.frame(c=c(1,NA,NA,4:10)) ST4 <- data.frame(d=c(NA,NA,NA,NA,NA,NA,NA,NA,NA,NA)) ST5 <- data.frame(e=c(1,2,3,4,NA,NA,7:9,NA)) ( in this example, the aim is to keep only in the list.files: ST1, ST3 and ST5 because they all contains at least 2 non-NA values in the 5 first lines, and so to remove from the list.files ST2 and ST4 because they contain both too much NAs in the first 5 lines). Hope you've understood! Thanks again! -- View this message in context: http://r.789695.n4.nabble.com/select-part-of-files-from-a-list-files-tp4630769.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ 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.
Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/