similar to: How to get rid of NULL in the result of apply()?

There are a few version of apply() (e.g., lapply(), sapply()). I'm wondering if there is one that does not return anything but just silently apply a function to the list argument. For example, the plot function is applied to each element in 'alist'. It is redundant to return anything from apply. apply(alist,function(x){ plot each element of alist})

Hi, There are quiet a few different 'apply' functions, such as lapply, sapply and many more. I'm very familiar with the 'Apply' function in Mathematica. Can somebody point me a summary of all the 'apply' functions in R. Also, I'm curious that what 'l' and 's' (and other prefixes) stand for in 'lapply' and 'sapply' Regards, Peng

Hi, I am wonder if there is a function similar 'apply' but it could accept multiple arguments? For example, I have the following matrix. x=matrix(1:6,nr=2) y=matrix(1:6,nr=2) I want to find a function that can be used to compute the linear regression for each pair of rows in the two matrices? multiple_apply(x,y,1,function(u,v){lm(u ~ v)} That is, I wound like something like the above

Hi, I am wondering if some experienced users would help put the ready-to-run code of the examples in the manuals. It would help new users learn R faster by putting all the examples in an ready-to-run R script file. Can somebody help do so sometime and post the code along with the pdf manuals? http://cran.r-project.org/manuals.html Regards, Peng

http://cran.r-project.org/doc/FAQ/R-FAQ.html#How-can-I-set-components-of-a-list-to-NULL_003f The explanation on this FAQ entry is not clear. It says '... similarly for named components...'. What I understood was x[i]<-list(NULL) is the same as x$a_name<-list(NULL). But, they are not. As the example below shows, x$a_name<-list(NULL) is the same as x[[i]]<-list(NULL). >

Some examples in the help page are too long to be copied from screen. Could somebody let me know some easy way on how to extract the example to a file so that I can play with them?

I don't find a function to print a string to file. Would somebody let me know what function I should use?

Hi, > x=c(rep(1,3),rep(3,2)) > x [1] 1 1 1 3 3 > duplicated(x) [1] FALSE TRUE TRUE FALSE TRUE > As shown in the above code, 'duplicated' doesn't return 'F' for the first '1' and first '3' in 'x'. I am wondering if there is a function that can return an indicator for any element whether it appears in a vector twice or more. Regards, Peng

I found this paper on ANOVA on unequal error variance. Has this be incorporated to any R package? Is there any textbook that discuss the problem of ANOVA on unequal error variance in general? http://www.jstor.org/stable/2532947?cookieSet=1

Hi, I'm learning the tutorial. http://llvm.org/docs/tutorial/ I'm wondering if there is already a git repository of the examples in the tutorial so that I don't have to copy the code from the webpage. Thanks! -- Regards, Peng

read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R > read.table("empty_data.txt") Error in read.table("empty_data.txt") : no lines available in input Execution halted $ cat read_empty.R read.table("empty_data.txt") $ cat

Hi, x=matrix(1:60,nr=6) I can refer the last 2 rows by x[5:6,] If I don't know the total number of rows is 6, is there a way to refer the last 2 rows? Regards, Peng

> > but doesn't emit optnone and nounwind attributes > s/nounwind/noinline On Mon, Jan 28, 2019 at 11:35 AM Jakub (Kuba) Kuderski < kubakuderski at gmail.com> wrote: > As far as I understand, gllvm doesn't run LTO pipeline or any cross-module > optimization, and the optimization level provided is only used to compile > each Translation Unit separately. > If you

Hi, I'm wondering if R provide a vi mode in the command line just like other shells such as bash do. Can somebody let me know? Regards, Peng

Hi, I am looking for a reference page that gives me a complete list of R string manipulation operations. At this moment, I am looking for something like basename and dirname. The following webpage doesn't give me any information. Can somebody point me a better resource? http://wiki.r-project.org/rwiki/doku.php?id=rdoc:base:basename Regards, Peng

I can exclude columns by column number using '-'. But I wondering if there is an easy way to exclude some columns by column names. > x=cbind(c(1,2),c(3,4)) > x [,1] [,2] [1,] 1 3 [2,] 2 4 > colnames(x)=c('a','b') > x a b [1,] 1 3 [2,] 2 4 > x[,-'a'] Error in -"a" : invalid argument to unary operator > x[,-1] [1] 3 4

Hi, I don't quite understand what are the return values of aov. I know that it has 'coefficients'. But I need to know what all the other return values are. Can somebody let me know how to figure them? Value: An object of class 'c("aov", "lm")' or for multiple responses of class 'c("maov", "aov", "mlm",

Hi, I am wondering how to pop up the graphics window from Rscript. I run the following code, but I don't see the graphics window, even transiently. Regards, Peng $ Rscript plot.R > x=1:10 > y=1:10 > plot(x,y) >

Hi, I have llvm installed through MacPorts. But I don't see macports installed. Are there supposed to be manpages of commands like lli installed? -- Regards, Peng

I did a search on www.rseek.org to look for the function to test if a vector is ordered or not. But I don't find it. Could somebody let me know what function I should use?