similar to: date calculation

Are they the same with .RData being the newer format?? Thanks, ...Tao

Hi list, I want to draw a bar plot with color indicating one grouping and different shading on top of the color indicating another grouping.? How should I proceed? Thanks! ...Tao

Hi list, I've encounter this problem (see below).? I know it's particularly R-related and it's easy to get by but it still bothers me a lot.? It looks the last character of "N.C. " is a space to me, but it's clearly not.? Can someone tell me a way to figure out what character is in the last position. Thanks! Tao > levels(dat$flag)[3] [1] "N.C.?" >

Hi list, Can somebody explain why there are these warning messages?? I just don't get it.? I'm using R 2.15.1 on WinXP. Thanks! Tao > x [1] -2.143510 -1.157450 -1.315581? 1.033562 -1.225440 -1.179909 >? ifelse(x>0, log2(x), -log2(-x)) [1] -1.099975 -0.210950 -0.395700? 0.047625 -0.293300 -0.238675 Warning messages: 1: In ifelse(x > 0, log2(x), -log2(-x)) : NaNs produced

Hi list, Is there a way to load one specific object from a .RData file which contains multiple data objects?? Thanks, ...Tao

Hi list, I have a bunch of .csv files that are password-protected. I wonder if there is a way to read them in in R without manually removing the password protection for each file? Thank you very much! ...Tao [[alternative HTML version deleted]]

Hi list, Is there a R function I can use to extract the worksheet names from an Excel file?? If no, any other automatic ways (not using R) to do this? thanks! ...Tao

Hi list, I was trying to use "predict.coxph" to calculate martingale residuals on a test data, however, as pointed out before http://tolstoy.newcastle.edu.au/R/e4/help/08/06/13508.html predict(mycox1, newdata, type="expected") is not implemented yet. Dieter suggested to use 'cph' and 'predict.Design', but from my reading so far, I'm not sure they can

R-listers, I have noticed several posts on issues with difftime producing NA's but they have been for older versions of R. Here's the issue associated with difftime that I am dealing with in R 2.12.2. > preciptime = strptime("01/10/2007 14:00",format="%m/%d/%Y %H:%M") > class(preciptime) [1] "POSIXlt" "POSIXt" > # Now using difftime, this

Dear all, I have a vector generated using the function strptime: > my.dt [1] "2004-04-19 08:35:00 W. Europe Daylight Time" "2004-04-19 09:35:00 W. Europe Daylight Time" "2004-04-19 11:35:00 W. Europe Daylight Time" [4] "2004-04-19 13:35:00 W. Europe Daylight Time" "2004-04-20 07:50:00 W. Europe Daylight Time" > class(my.dt) [1]

Hi list, I was running Sweave on one of my .rnw file.? Everything was fine, until I came back from the vacation.? Nothing changed (at least to my knowledge), but now I have this problem: >???? Sweave("myfile.rnw") Error: ?COLO001final.rnw? is not ASCII and does not declare an encoding After snooping around on the web, I found this solution: > Sweave("myfile.rnw",

Hi list, Is there a way in "rpart" to force the variables only used once when doing the splits? This is how the question came about. Often time, the tree constructed uses the same variable (say X1) for the first and second splits, for example. However, due to practical reason, the researcher doesn't like this. The prefer to see the second split using other variables (say X2).

Hi list, Is there a function that can let me know which functions are being debugged? I know I'm probably not doing a very good job of keeping track of things, but it does get messier when you dig into different layers of a function. I know there is "isdebugged", but it only works on one function at a time. Thanks! ...Tao [[alternative HTML version deleted]]

Hi list, Is there already a function somewhere to output the confusion matrix from two input vectors? "table" always automatically delete rows or columns with all 0's. For example, I would like the columns for "10" and "30" added back. Thanks! ...Tao 20 40 50 60 70 80 90 100 10 0 0 1 0 0 0 1 0 20 1 2 0 4 0 0 0 1 30 0 0

Hi Allen and list, See the code below.? I've tried it on R2.13 and R2.8.0 using either heatmap.plus 1.3 or the latest.? All gave the same results.? The problem is in the last line: when I tried to plot two different color bars, the one corresponding to "cm.colors(10)" is not correct (it starts with one black and one red.? Not sure where they're from?) Any ideas? Thanks!

Hi list, Is there a easy way to compare objects in two different workspace files (i.e. .RData files) in R?? I can use some generic file compare softwares (e.g. BeyondCompare) to binary comparison, but when it says they're different you can't tell where the difference are from. Thanks! Tao

I am a beginner in R with a background in SAS. Are there built-in R methods of reading dates for calculating elapsed days between two calendar dates? If so, are there any examples I can browse? Thanks in anticipation. John Byrne. Lecturer in Information Systems. Australian Catholic University.

Hello all, I am manipulating a large database with 70,000 records. "strptime" generates a date variable but R treats some of the values as NA. I attach a simple example below. I have spent hours on this problem. Any hint would be greatly appreciated. Many thanks, Edwin Sun # =======start of sample code ============= > x <- c("2005-04-02 19:03:00", "2005-04-03

Colleagues, I submitted this several days ago and no one responded, so I am trying again, trying a different subject line: I just encountered some unexpected behavior of difftime in relationship to the change from daylight savings to standard time. My understanding is that DST and ST take effect at 2AM. However, the results below suggests that R (version 2.8.0 in OS X) implements the

Hi. I'm trying to take the difference in days between two times. Can you point out what's wrong, or suggest a different function? When I try the following code, The following code works fine: a <- strptime(1911100807,format="%Y%m%d%H",tz="GMT") b <- strptime(1911102718,format="%Y%m%d%H",tz="GMT") x <- difftime(b, a,