similar to: Aggregating by a grouping

I have a dataframe as follows: Date time value 20110620 11:18:00 7 20110620 11:39:00 9 20110621 11:41:00 8 20110621 11:40:00 6 20110622 14:05:00 8 20110622 14:06:00 6 For every date, I want to extract the row that has the greatest time. Therefore, ending up like: 20110620 11:39:00 9 20110621 11:41:00 8 20110622 14:07:00 6 I am using for loops (for every date, find largest time value) to do

Hi, I am doing the following: 1. I have a list of files.. Files1=list.files("some directory",pattern="some pattern") 2. I define a list as res=vector("list", length(files1)) 3. I read all the files into this list: res=lapply(files1, read.csv) I now want to rowbind all the items in the list into one big mass (all files have same number of columns). I tried

Hi all: I have a directory of files as in -------------> bunchafiles <- list.files(path="/data/2.3/2006", pattern="returns", full.names=T,recursive=T) .... Each file is a bunch of returns for a particular date (unique). There are like 252 files or so. With a custom function myread (below), I define a vector ----- res <-

Hi, I have an vector object that looks like DA <- c("1991q1", "1993q2") (first quarter of 1991 etc) and I want to convert it into a date object using as.Date(). I did this for montly data but am stumped when it comes to dealing with quarterly data and as.Date. Would anyone be able to help? Would be very grateful for any advice, sorry for being such an R-newbie!

Hi I am plotting a set of data inside a for loop. Is it possible to use plot in for loop without redrawing the whole plot? Am using par(new=TRUE) but that draws on top of the previous plot. Couldn't find any threads about the topic. Thanks Mohan --

Hi, I need your help. I have downloaded a precompiled JRI as part of rJava. I have included rJava as part of my R package libraries. Now I need to be able to work with some R functions from my Java apps. I'm using NetBeans on Windows. I have followed some instructions from http://www.rforge.net/JRI/ but i keep on getting errors when compiling my Java app as follows: run: Cannot find JRI

Hi, I have a scatter plot, with an equation that best fits the scatter plot expressed as: 1/x^.6. I know for normal linear regression lines you can use the abline() command; however, since my best fit line is not linear, how can I draw my line on the scatter plot in a similar fashion to abline(). Thanks for everyone's help again. I appreciate this board's advice. Mark

I have created this data frame to help illustrate my problem. id<-c(rep(1,5),rep(2,5),rep(3,5),rep(4,5),rep(5,5)) x<-rep((seq(1:5)),5) y<-c(0, 0.1, 0.5, 0.4, 0.2, 0, 0.1, 0.5, 0.4, 0.12, 0, 0.1, 0.5, 0.55, 0.2, 0, 0.1, 0.5, 0.3, 0.2, 0, 0.1, 0.6, 0.4, 0.1) d1<-cbind(id,x,y) I would like to delete all rows where id=4, however, when I tried the command  d2=d1[-c(id==4),] and looked

Hi all, Is there an easy way to do cumulative matrix multipliation in R? What's the syntex? Thanks. Sincerely, Yanwei Zhang Department of Actuarial Research and Modeling Munich Re America Tel: 609-275-2176 Email: yzhang@munichreamerica.com<mailto:yzhang@munichreamerica.com> [[alternative HTML version deleted]]

I just installed R 2.8.1 for windows. When I try to start the software I get the following: Fatal error: unable to restore saved data in .RData. Note that on my previous section I tried to read a large dataset and I got a message stating that no enough memory was avaliable (I don't have the complete log for that section) I wanted to ask how can I go about solving this problem, or do I need

Hi,I would like to reshape the following "wide" data set to "long" form. I would appreciate help with the correct code for "reshape". I tried a few unsuccessfully. Thanks. Chetty __________________________________________________ dat.1 Grp X0 X3 X6 X12 X25 X501 C 0.5326517 0.6930942 0.9403883 1.157571

Hello. I am trying to load the rJava package in R-2.7.2 (Windows XP 64-bit RGui) and get the following error message even though the mentioned .dll file is located at the directory listed in the error message. I have tried to uninstall and reinstall the package but that does not resolve the problem. Then uninstallation and re-installation of R did not resolve the issue either. Any suggestions are

Hi everyone, I'm trying to use the acf() function to calculate the autocorrelation of each column in a matrix. The trouble is that I can only seem to get the function to work if I extract the data in the column into a separate matrix and then apply the acf() function to this column. I have something like this: acf(mat,lag.max=10,na.action=na.pass) ...but I would really like to apply the

hi there, Is there any function to append the pdf file. I want to write in a pdf file some 100 plots(in one single pdf containing 100 plots) while all the plot are created using a for loop. I can create 100 pdf one for each for each plot using a for loop but i want only one pdf with 100 plots. Ramya -- View this message in context:

Dear all, I am trying to manually re-sort rows in a number of tables. The rows aren't sorted on any particular values but are simply ordered by user choice (as shown by the row numbers in the code). I have been able to carry out each re-arrangement without the use of the 'for' loop, but cannot seem to successfully execute the statements when incorporated into the loop. The code I have

Hi all, I have this figure: http://docs.google.com/Doc?id=df5zfsj4_103rjt2v4d5 created with the following steps: > x [1] 90.4 57.8 77.0 103.7 55.4 217.5 68.1 85.3 152.0 113.0 97.1 89.9 [13] 68.1 83.7 77.4 34.5 104.9 170.3 88.6 88.1 108.8 77.4 85.6 82.7 [25] 81.3 108.0 49.5 71.0 85.7 99.3 203.5 275.9 51.1 84.8 16.5 72.6 [37] 160.5 158.3 136.7 140.0 98.4 116.1

Hi R-experts, suppose I have a list with containing data frame elements: [[1]] (Intercept) y1 y2 y3 y4 -6.64 0.761 0.383 0.775 0.163 [[2]] (Intercept) y2 y3 -3.858 0.854 0.834 Now I want to put them into ONE dataframe like this: (Intercept) y1

Hello all, I hope some of you can come to my rescue, yet again. I have two genetic datasets, and I want one of the datasets to have only the columns that are in common with the other dataset. Here is a toy example (my real datasets have hundreds of columns): Dataset 1: Individual SNP1 SNP2 SNP3 SNP4 SNP5 1 A G T C A 2 T C A G T 3 A C T

Dear all, I'm trying to read in a whole directory of files which have two variable parts to the file name: year and month. E.g. comp198604.asc represents April of 1986 - 'comp' is fixed in each case. Years range between 1986 to 1995 and months are between 1 and 12. Just to be clear, there are 12 files associated with each year: e.g. comp198601, comp198602, ... comp198612 through to

Hi all, I have a 4 by 4 matrix, and I want to switch row 2 and row 3 first, then switch column 2 and column 3. Is there an easy way to do it? The following is a tedious way to get what I want. But I wonder if there is a way to simplify this. > a=matrix(rnorm(16),4,4) > a [,1] [,2] [,3] [,4] [1,] 0.33833811 -0.9422273 -0.06181611 -1.8346134 [2,] -0.68167996