search for: shidaxia

Hi list, Could someone explain to me why the following result is not a integer? > difftime(strptime("24NOV2004", format="%d%b%Y"), strptime("13MAY2004", >format="%d%b%Y"), units="days") Time difference of 195.0417 days I'm using R2.12.0 on WinXP. Thanks! ...Tao

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

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 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 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 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, 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 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

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]]

...the two P-values are nearly the same. However, I don't understand why they should be so different, since the set of all possible 2x2 tables will be the same in both cases. I would be interested in knowing how this happens. Ravi. ----- Original Message ----- From: "Shi, Tao" <shidaxia at yahoo.com> Date: Tuesday, July 15, 2003 4:37 pm Subject: RE: [R] Why two chisq.test p values differ when the contingency > Hi, Ted and Dennis: > > Thanks for your speedy replies! I don't think this happens just > randomly, rather, I'm thinking it may be due to the way...

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

...------------------- Message: 91 Date: Sat, 30 Oct 2010 02:54:53 +0000 (UTC) From: Ben Bolker <bbolker@gmail.com> To: r-help@stat.math.ethz.ch Subject: Re: [R] date calculation Message-ID: <loom.20101030T045356-623@post.gmane.org> Content-Type: text/plain; charset=us-ascii Shi, Tao <shidaxia <at> yahoo.com> writes: > Could someone explain to me why the following result is not a integer? > > > difftime(strptime("24NOV2004", format="%d%b%Y"), strptime("13MAY2004", > >format="%d%b%Y"), units="days") > Time...

Hi list, This is probably too much to ask, but I'm wondering if there is a ready-to-use function somewhere that allows me to color one area of a venn diagram (e.g. the intersection of two sets)? Thanks! ...Tao

Hi list, I know this is not hard to implement based on the returned objects from ROC, ROCR or a couple of other roc-related packages. I'm just wondering if there is already such a function exist. Thanks! ...Tao

Hi list, I have a function which basically is a wrapper of pairs with some useful panel functions. However, I'm having trouble to pass the "xlim" and "ylim" into the function so the x and y axes are in the same scale and 45 degree lines are exactly diagonal. I've looked at some old posts, they didn't help much. I think this is b/c I have multiple panel