similar to: how to read in only some columns of a data file

Displaying 20 results from an estimated 10000 matches similar to: "how to read in only some columns of a data file"

2009 Jul 21
4
how to transform m/d/yyyy to yyyymmdd?
Hello, I have a set of data that has a Date column looks like this: 12/9/2007 12/16/2007 1/1/2008 1/3/2008 1/12/2008 etc. I'd like the date to look something like the follow (so that I could sort by date easily). 20071209 20071216 20080101 20080103 20080112 How to do it? Thank you very much Julia -- View this message in context:
2008 Sep 11
3
Calculate mean/var by ID
Hello, I have a data set that looks like this. ID value 111 5 111 6 111 2 178 7 178 3 138 3 138 8 138 7 138 6 . . . I'd like to calculate the mean and var for each object identified by the ID. I can in theory just loop through the whole thing..., but is there a easier way/command which let me calculate the mean/var by ID? Thanks, Julia -- View this
2008 Oct 10
4
how to store lme/lmer fit result
Dear R users, I am building a hierarchical model on a large data set. It can take quite some time to finish one fit, I was just wondering whether it is possible to store the fit object (the result) to a file for later (offline) analysis. thanks Julia -- View this message in context: http://www.nabble.com/how-to-store-lme-lmer-fit-result-tp19910951p19910951.html Sent from the R help mailing
2009 Jun 01
2
how to checking whether elements of a vector changed or not.
Hello, I have a vector: x <- c("A", "A", "A", "B", "A", "A", "C") I'd like to compare each of elements of vector x from its previous element (except for the 1st element which does not have previous element). So I'd like to get a vector y (of same length) that looks something like (0, 0, 0, 1, 1, 0, 1) or (F, F, F,
2009 Jan 12
3
roll weekly data to monthly level
Dear R users: I have a data set that looks something like this: ID time y 1 2/01/2008 4 1 2/09/2008 12 1 9/01/2008 8 2 1/06/2008 3 2 3/01/2008 4 2 3/09/2008 9 2 6/03/2008 4 3 1/02/2008 3 3 1/10/2008 8 3 2/02/2008 7 3 2/10/2008 3 I'd like to sum up the weekly data to the monthly level, so that it looks something
2008 Sep 30
1
Adding legends to a plot
Hello, I have a time series plot drawn using 3 different colored lines, each line corresponds to different category group. I'd like to put legends on the plot. I am using "legend" to do this, however, I can either specify lty or col in legend. Will I be able to do the following in the legend box: a solid black line then g1, a solid red line then g2, a solid blue line then g3?
2009 Feb 11
3
two scatter plots in one
Dear R users, I need to compare two scatter plots, plot(x1, y1) plot(x2, y2) and would like to plot them in the same figure. How do I do it? Thank you. -- View this message in context: http://www.nabble.com/two-scatter-plots-in-one-tp21963375p21963375.html Sent from the R help mailing list archive at Nabble.com.
2008 Oct 30
1
How to increase iteration limit for lmer()?
Dear R users: I am running lmer(), and I had the following warning message: "In mer_finalize(ans): iteration limit reached without convergence (9) What is the default limit for lmer()? And how do I increase the limit? Many thanks, Julia -- View this message in context: http://www.nabble.com/How-to-increase-iteration-limit-for-lmer%28%29--tp20252974p20252974.html Sent from the R help
2008 Oct 16
1
increase memory limit in R
Dear R users, I am running lmer() and having memory problem: "reached total allocation of 1535Mb". The lmer() function was successful (no errors or warnings). However when I do "summary(fit.lmer), I got this "Error: cannot allocate vector of size 19.5 Mb). I used memory.size() and got 1880. I used memory.limit(2500) to increase the memory size to 2500Mb, however I still get
2009 May 29
1
frequence of patterns in a vector
Dear R users, Suppose I have a vector that consists of characters like ABC, A02, RCA, etc., and there are about 700 of possible characters. For example, x <- c("ABC", "ABC", "ABC", "A02", "ABC", "RCA", "ABC", "ABC") I'd like to get a frequency matrix that looks something like this: ABC 6 A02 1 RCA 1 I
2009 Sep 24
1
multinormial runs tests?
Dear R users, I would like to test the randomness in a series of N values (N>=2). I know that runs.test works for dichotomous factor only: x <- rep(c(1,2), 50) runs.test(factor(x)) However it doesn't work for series that can take any N values (N>2): x <- rep(c(1,2,5,4),50) runs.test(factor(x)) Error in runs.test(factor(x)) : x does not contain dichotomous data Are there any R
2011 Mar 21
3
Computing row differences in new columns
Hi I have the following columns with dates and results, sorted by subject and date. I'd like to compute the differences in dates and results for each patient, based on the previous row. Obviously the last entry for each subject should be a NA. Which would be the best way to accomplished that ? I guess questions like that have been already answered a thousand times, so I apologize for
2010 Oct 04
3
read columns of quoted numbers as factors
Suppose I have a data file (possibly with a huge number of columns), where the columns with factors are coded as "1", "2", "3", etc ... The default behavior of read.table is to convert these columns to integer vectors. Is there a way to get read.table to recognize that columns of quoted numbers represent factors (while unquoted numbers are interpreted as
2002 Nov 27
1
read.table: colClasses when num. of columns is unknown
Hi, I am looking for a way to read tables that have general structure of characterTag num1 num2 ... i.e. one character column followed by an unknown to the caller (but fixed throughout the file) number of numeric columns. I wanted to improve the speed of read.table by using colClasses, but that seemed to require knowledge of the actual number of columns in the file. For example I tried
2009 Jan 20
2
Summing Select Columns of a Data Frame?
Hi, I would like to operate on certain columns in a dataframe, but not others. My data looks like this: x1 x2 x3 1 2 3 4 5 6 7 8 9 I want to create a new column named x4 that is the sum of x1 and x2, but NOT x3. I looked at colSums and apply, but those functions seem to use all the columns in a dataframe. How do I only use select columns? If it helps, in Stata this would be gen x4
2012 Apr 23
1
Can I specify POSIX[cl]t column classes inside read.csv?
I'm loading a nicely formatted csv file. ? ? #!/usr/bin/env Rscript ? ? kpi <- read.csv( ? ? ? # This is a dump of the username, date_joined and last_login columns ? ? ? # from the auth_user Django table. ? ? ? 'data/2012-04-23.csv', ? ? ? colClasses = c('character') ? ? ) ? ? print(kpi[sample(nrow(kpi), 3),2:3]) Here's what the three rows I printed look like. ? ? ? ?
2009 Jan 18
2
Deleting columns based on the number of non-blank observations
Hello, I have a dataset (named "x") with many (966) columns. What I would like to do is delete any columns that do not have at least 375 non-blank observations (i.e., the cells have some value in them besides NA). How can I do this? I have come up with the following code to _count_ the non-blank observations in each column, but how would I adapt this code to _delete_ columns from the
2011 Mar 15
1
How to read only specified columns from a data file
R-help, I'm trying to read a data file with plenty of columns. I just need the first 5 but it doe not work by doing something like: > mycols <- rep(NULL, 430) ; mycols[c(1:4)] <- NA > read.table(myfile, skip=2, colClasses=mycols) Any suggestions? Thanks in advance
2012 Jul 25
3
ff package: reading selected columns from csv
*Dear R users, Ive just started using the ff package. There is a csv file (~4Gb) with 7 columns and 6e+7 rows. I want to read only column from the file, skipping the first 100 rows. Below Ive provided different outcomes, which will clarify my problem * > sessionInfo() R version 2.14.2 (2012-02-29) Platform: x86_64-pc-mingw32/x64 (64-bit) locale: ... attached base packages: [1] tools
2010 Oct 13
1
Loop in columns by group
Dear all, I need to do a loop as following: #Consider a matrix: M <- matrix(1, nrow=10, ncol=20) #Matrices to store the looping results M1 <- matrix(0, nrow=10, ncol=400) h <- c(1:20/1000) #loop for (j in h){ M1 <- M/(2*j) } But this means that the first 20 columns of matrix M1 (that is, columns 1:20) should show the results of M/(2*0.001). Then, the following 20