similar to: locate the needed columns

Displaying 20 results from an estimated 10000 matches similar to: "locate the needed columns"

2012 May 22
3
pad leading zeros in front of strings
Dear All, This question sounds very simple but I don't know where I am wrong. I just want to pad leading zeros in some string, for example, "123" becomes "00123". What is wrong if I do following? > sprintf("%05s", "123") [1] " 123" It didn't return "00123", instead it padded with 'blank'. Thank you for your help
2011 Feb 25
7
R in different OS
Hi All, I have two Rs, one has been installed in Windows system and another one has been installed under UNIX system. Is there any environmental variable or function to tell me which R I am using? The reason that I need to know it is under different system, the data path could be different. I want to do something like if it is R under Windows path =
2011 Feb 10
2
Repeaded sampling
Hi all, I have a dataset. Each time I want to sample N(i) elements from it and I want to repeated sampling M times. N(i) is varied from time to time. For example, dataset = 1:50; a = list(); M = 1000; I want to do something like for(i in 1:M) { a[[i]] = sample(dataset,
2012 Apr 10
1
re-install a package
Hi All, I have a self-cooked package and save it to a zip file after running make, say named xxx.zip. After installing it to R by running "Install packages from local zip files" under Packages menu in R (Windows), I realized I needed to change some source codes and re-make it. My question is that if I need re-install that package or R would automatically update the R
2011 Mar 10
1
aggregate by part of a field
Hi All, I have a data frame like a = data.frame(date = c(20081201, 20081202, 20081201), product = c("a b c d e", "a b c g h t", "d e h a c e h g"), sales = c(1, 2, 3)) Now I want to aggregate the sales by part of the a$product. 'Product' is the product name, a string separated by a space. The key in my aggregate function is
2012 Jul 09
1
install.packages
Hi All, I have two questions regarding install.packages(). Q1: may I run it in non-interactive mode, which means just install the packages I want rather than letting me to choose which mirror etc? Q2: I ran a R code in batch mode, for example, R CMD BATCH a.r In a.r, I have some statements like packages = library()$result[, "Package"]; f(! "plyr" %in% packages) {
2012 Oct 26
1
backward stepwise model selection
Hi All, I know in R there is function named 'step', which does the stepwise regression and choose the model by AIC. However, if I want to choose a model per this logic: 1. Run a full model (linear regression, f = lm(y ~., data = ZZZ), for example) 2. Pick up the variable with biggest p value, delete it from the module and get a new regression model. 3. Repeat step 2
2013 May 02
2
Self-developed package -- installation
Hi All, I have a question about package installation in R. We have developed a package, say 'ABC'. We have installed it in two machines, A and B by running 'Install Package(s) from local zip file'. Everything was fine. Right now, suppose that package got damaged in machine A and our zipped file is gone, My question is that may I directly copy ../library/ABC from machine B to
2012 May 03
2
apply one list to another one
Hi All, Suppose I have the following codes: x = data.frame(A = rnorm(20), B = rnorm(20), C = rnorm(20)) a = list() a[["1.1"]] = x a[["1.2"]] = x b = list() b[["1.1"]] = c("A", "B") b[["1.2"]] = c("B", "C") Now I want to apply b to a like this, for each element of 'a', only select the corresponding columns
2012 Nov 06
2
R and SPSS
Hi group: I have a data set, which has severe colinearity problem. While running linear regression in R and SPSS, I got different models. I am wondering if somebody knows how to make the two software output the same results. (I guess the way R and SPSS handling singularity is different, which leads to different models.) Thanks. [[alternative HTML version deleted]]
2011 Apr 21
3
line type lty
Hi All, Does somebody know how to know the detail of the line types? For example, lty = 1, means what kind of line?, lty = 2, means what kind of line? Thanks. HXD [[alternative HTML version deleted]]
2013 Jan 24
1
how to read a website with Chinese Character
Hi all, I am planning to parse some information on a website which includes lots of Chinese characters. Does someone know how to read/display Chinese in R? Thanks. url = "http://www.teec.org.cn/html/renwujieshao/" x = readLines(url) I tried encoding = 'UTF-8' already but it didn't help. My R version is $platform [1] "i386-pc-mingw32" $arch [1] "i386"
2012 Jul 11
1
Variance Inflation factor
Hi All, I need to calculate VIF (variance inflation factor) for my linear regression model. I found there was a function named vif in 'HH' package. I have two questions: 1) I was able to install that package in my R under windows. But while trying to install that package in UNIX, I got error: Package HH is not available. Does somebody know why? 2) Does
2011 Feb 16
1
speed up the code
Hi All, The following is a snippet of my code. It works fine but it is very slow. Is it possible to speed it up by using different data structure or better solution? For 40000 runs, it takes 8 minutes now. Thanks a lot fun_activation = function(s_k, s_hat, x_k, s_hat_len) { common = intersect(s_k, s_hat); if(length(common) != 0) { index = match(common, s_k);
2008 Feb 11
2
how to generate a column based on other columns in a data frame
HI, I am working on a data set with multiple collections of mosquitoes at sampling sites. Each row represents a collection of individual samples with coordinates for each collection. ... X, Y,... 1 36.435 30.118 2 36.435 30.118 3 36.435 30.118 4 35.329 29.657 5 35.329 29.657 6 36.431 30.111 7 36.431 30.111 8 35.421 29.797 9 35.421 29.797 10 35.421 29.797
2011 Mar 24
2
apply mean to a three-dimension data
Hi All, Suppose I have data like [[alternative HTML version deleted]]
2013 Apr 03
1
how to re-shape a matrix
Hi All, I have a matrix like m <- matrix( letters[1:10], ncol=5) How to conver it to 10 * 3 matrix, which the first col is row index of m, second col is colum index of m and third column is the value of matrix, say 1 1 1 "a" 2 1 2 "c" 1 3 "e" etc... Thanks. [[alternative HTML version deleted]]
2011 Jul 13
3
adding text to spplot
hi all, I have a plot to which i would like to add text labels. And i cant find a way...here is the code : enaD2<-idw(D2~1, loca=dva, newdata=grd) pts = list("sp.points", dva, pch = 20, cex=1.5, col = "darkred spplot(enaD2, "var1.pred",sp.layout=pts, main = "globina 60 cm", sub="D2",
2008 Feb 08
4
how to extract characters from a character string
Hi, I ran into a problem when I complied a dataset with UTM coordinates. For calculating distances between sites, I need to reformat the coordinates from, for example, 32?35.421 N, to 35.421, i.e. I need to delete all digits before symbol ? and a space and N at the end of the string. What functions I should use? Thanks in advance. Weidong Gu, Department of Medicine University of
2011 Jun 03
1
debug R code
Hi List, I have a question regarding debug R code. I know I can use debug(fuction_name) and when code runs to that point, it will go to debugger. My question is inside debugger, how to stop a code at a specified line. For example, in C (gdb or dbx debugger) I can run "stop at 123" (stop at line 123) or 'b 123' (break at line 123). Is there any similar commend in R