similar to: select element from each row of the matrix

Dear list, I wonder if there a better way to have rbind/cbind/append to create the first element (if it is empty) instead of doing the following in a loop? for (i in 1:10) { if (i == 1) { aRow = SomeExpression(i) } else { aRow = rbind(aRow,SomeExpression(i)) } } Thanks Anthony

Hi everyone! I have a question about data processing efficiency. My data are as follows: I have a data set on quarterly institutional ownership of equities; some of them have had recent IPOs, some have not (I have a binary flag set). The total dataset size is 700k+ rows. My goal is this: For every quarter since issue for each IPO, I need to find a "matched" firm in the same

I have an array with names which contain multibyte characters. ?When I try to write the array to a file using write.table and row.names = T I receive an error message when the first such name is encountered, saying that I have not specified the option to generate NA instead. ?I really would be satisfied if the row name in the file were exactly what is displayed when I print the array on the

> I wanted to simulate the Matlab DISPLAY function for some time now. After seeing a recent proposal by Gabor Grothendieck I came up with the following solution, display <- function(...) { my_names <- lapply(substitute(placeholderFunction(...))[-1], deparse) for (my in my_names) cat(my, "=", eval(parse(text=my)), "\n", sep=" ") } that works about as

Hi All, I have a 1000x1000000 matrix. The calculation I would like to do is actually very simple: for each row, calculate the frequency of a given pattern. For example, a toy dataset is as follows. Col1 Col2 Col3 Col4 01 02 02 00 => Freq of ?02? is 0.5 02 02 02 01 => Freq of ?02? is 0.75 00 02 01 01 ? My code is quite simple as the following to find the pattern ?02?.

I have the complete data like id time censor 1 10 0 1 20 0 1 30 0 2 10 0 2 20 1 2 30 0 2 40 0 3 10 0 3 20 0 3 30 1 .... for id 1, i want to select the last row since all censor indicator is 0; for id 2, i want to select the row where censor ==1; for id 3, i also want to select the row where censor==1. So if there is a 1 for censor, then I want to select such a row, otherwise I want to select the

I have the following data ID x y time 1 10 20 0 1 10 30 1 1 10 40 2 2 12 23 0 2 12 25 1 2 12 28 2 2 12 38 3 3 5 10 0 3 5 15 2 ..... x is time invariant, ID is the subject id number, y is changing over time. I want to find out the difference between the first and last observed y value for each subject and get a table like ID x y 1 10 20 2 12 15 3 5 5 ...... Is there any easy way to generate

Dear r-helpers, I have a very simple question. Suppose my data is like id=c(rep(1,2),rep(2,2)) b=c(2,3,4,5) m=cbind(id,b) > m id b [1,] 1 2 [2,] 1 3 [3,] 2 4 [4,] 2 5 I wish to select the first observation for each id. That is, I want to quickly select two rows: id b 1 2 2 4 only. how should i do this? [[alternative HTML version deleted]]

Hello, I am trying to obtain f-values for response (independent) variables from a CCA performed in vegan package, to see which ones of them have significative influence in my dependent variables (like the manual selection in canoco), but I can't find any function (or package) that do such a thing. The dependents variables are species data, and the independents are ambiental data. Than you.

While trying to assemble a particular input file, my build system failed because the target object was too big. I calculated that the input source file after preprocessing would be about 3.91Mb. system: CYGWIN_NT-10.0 x86_64 Cygwin file: llvm-master/lib/Passes/PassBuilder.cpp build output: Scanning dependencies of target LLVMPasses [ 84%] Building CXX object

I want to take the first row of each unique ID value from a data frame. For instance > ddTable <- data.frame(Id=c(1,1,2,2),name=c("Paul","Joe","Bob","Larry")) I want a dataset that is Id Name 1 Paul 2 Bob > unique(ddTable) Will give me all 4 rows, and > unique(ddTable$Id) Will give me c(1,2), but not accompanied by the name column.

Hi All, I have a Quantum scalar i40 tape library. I need to configure it to TWO tape partition libraries, e.g., library_a and library_b, so that each library has its own tape drive. Then connect this physical tape library to two different CentOS servers so that each server can see its own media changer and tape drive. I once had a successful configuration on one host but NOT on the other. One

Hello R-users, I have a symmetric matrix of numerical values and I want to obtain those values in the upper or lower triangle of the matrix in a vector. I tried to do the job by using two for-loops but it doens't seem to be a clever way, and I'd like to know a more efficient code for a large matrix of thousands of rows and columns. Below is my code for your reference. Thanks a lot.

Hi, I'm a new user. I've been reading through the manual and looking at various examples but am still trying to make sense of the most efficient ways to handle matrices of data. If I have a 2D matrix of data, how do I get the mean, min, max value of each row? I see the "mean" function on a matrix will give me averages by row, but min and max give me the value for the entire

Hi Suppose I have a matrix (cohort are rows and years are columns) [2000] [2001] [2002] [2003] [C1] 0.01 0.03 0.02 0.09 [C2] 0.06 0.05 0.07 0.11 [C3] 0.1 0.5 0.4 0.98 [C4] 0.7 0.6 0.2 0.77 I want to extracts the diagonals to get a matrix which looks like this (C1 becomes C2 in 2002, C2 becomes C3 in 2003

Dear R Folks, I'm a big fan of R, but there are a couple of things that repeatedly annoy me, and I wondered if anyone has neat ways to deal with them. (a) When using "apply" row-wise to a matrix, it returns the results column-wise, and to preserve the original orientation, I've to do a transpose. E.g. I've to keep doing a transpose, which I consider to be quite

My unit's firmware: library 05.03, tape d22h, shows the device as set to random mode. But mtx -f /dev/st0 status gives an error that google says the device is in sequential mode. dmesg|grep -i hp does reflect CentOS thinks the device is a sequential unit. I've tried this with Fedora 8, too, and both show the same, so it is either an issue with CentOS/Fedora RPMs, or the version of

Hi, I'm still not quite there with my H-F (G-G) correction code. I have it working for the main effects, but I just can't figure out how to do it for the effect interactions. The thing I really don't know (and can't find anything about) is how to calculate the covariance matrix for the interaction between the two (or even n) main factors. I've looked through some books

Hi, I'm still not quite there with my H-F (G-G) correction code. I have it working for the main effects, but I just can't figure out how to do it for the effect interactions. The thing I really don't know (and can't find anything about) is how to calculate the covariance matrix for the interaction between the two (or even n) main factors. I've looked through some books

Hello all, To calculate the power of a matrix, I used the command "mtx.exp(X, n)", but there is an error saying "Error: couldn't find function "mtx.exp"". How can I deal with this problem? Jing