similar to: time series comparison

Hi, I am new to time-dependent Cox model to estimate time dependent hazard ratios. Let me use aml dataset from survival package: > aml3<-survSplit(aml2,cut=c(5,10,20),end="time",start="start", event="status",episode="i") If I want to esimate hazard ratio for each of the time intervals 0-5, 5-10, 10-20 and >=20, would the following calculate

Our CEO, Dr. Dan Steinberg, is planning to visit Europe in May. He would like the opportunity to introduce statisticians (and statistically minded people) to data mining, data mining applications and to forefront data mining tools. Our algorithms are probably familiar to many statisticians (CART, MARS, MART, TreeNet and RandomForests), although it isn't necessary to be a statistician to

I posted a similar question, but feel it needs a bit more elaboration. I have a data frame (read from a csv file) that may have missing rows. Each day has 7 time intervals associated with it, with a range from 17:00 hrs to 18:00 hrs in 10 minute bins. What I am looking for is a script that will run through the data frame and insert "NA"in the Volume column for any dates that are

Hello, Sometimes, when a call comes in from the PSTN through our VoIP gateway, the information that is sent to our web page that logs calls includes the original CID name instead of the one that is we expect to be rewritten on the fly using Asterisk's LookupCIDName: ================= ;extensions.conf [internal] exten => group,1,LookupCIDName exten =>

Dear R-users, In a randomized placebo-controlled within-subject design, subjects recieved a psycho-active drug and placebo. Subjects filled out a questionnaire containing 15 scales on four different time points after drug administration. In order to detect drug effects on each time point, I compared scale values between placebo and drug for all time conditions and scales, which sums up to

Hello I have 2 data frames DF1 and DF2 where DF2 is a subset of DF1: DF1= data.frame(V1=1:6, V2= letters[1:6]) DF2= data.frame(V1=1:3, V2= letters[1:3]) How do I create a new data frame of the difference between DF1 and DF2 newDF=data.frame(V1=4:6, V2= letters[4:6]) In my real data, the rows are not in order as in the example I provided. Thanks much Joseph [[alternative HTML version

I have a data frame that looks like this: V1 V2 V3 a b 0:1:12 d f 1:2:1 c d 1:0:9 where V3 is in the form x:y:z Can someone show me how to subset the rows where the values of x, y and z <= 10: V1 V2 V3 d f 1:2:1 c d 1:0:9 Thanks Joseph [[alternative HTML version deleted]]

Hi Matt Your method is the easiest way for me to install the 64-bit R. I followed the directions on your web site and then did the following: R --arch=x86_64 source("http://bioconductor.org/biocLite.R") biocLite(type = "source",lib = "/Library/Frameworks/R.framework/Versions/2.8/Resources/RLib64") I got many errors and warnings which I copied to the attached file.

Hi merge() takes only 2 data frames. What can you do to it to make take more than two data frames? or is there another function that does that? Thanks joseph ____________________________________________________________________________________ Looking for last minute shopping deals? [[alternative HTML version deleted]]

Hi, I am trying to plot odds ratios and the corresponding confidence intervals in horizontal segments. It would be ideal if the confidence interval segment can be drawn with little vertical bars at both ends. I have tried very hard to change the type of ends by using 'lend' arguments, but cannot make it. I even tried 'arrows()', but still failed. Following is the code I use:

All, The code below is for a pseudo dataset of repeated measures on patients where there is also a treatment factor called "drug". Time is treated as categorical. What code is necessary to test for a treatment effect at a single time point, e.g., time = 3? Does the answer matter if the design is a crossover design, i.e, each patient received drug and placebo? Finally, what would

Hello. A quick question about incorporating variation due to study in the metafor package. I'm working with a particular data set for meta-analysis where some studies have multiple measurements. Others do not. So, let's say the effect I'm looking at is response to two different kinds of drug treatment - let's call their effect sizes T1 and T2. Some studies have multiple

Hi David: In looking at your original post it is a bit difficult to ascertain exactly what your null hypothesis was. That is, you want to assess whether there is a treatment effect at time 3, but compared to what. I think your second post clears this up. You should refer to pages 224- 225 of Pinhiero and Bates for your answer. This shows how to specify contrasts. > -----Original Message-----

Greetings, Thanks for your time in reviewing the following role located in the RTP, NC area. Our client is a drug development platform technology company whose patent-pending intellectual property is poised to dramatically impact both drug discovery and development processes by accurately measuring the spectrum of biochemical changes and mapping these changes to metabolic pathways. The

Hello I have 2 data frames df1 and df2. I would like to create a new data frame new_df which will contain only the common rows based on the first 2 columns (chrN and start). The column score in the new data frame should be replaced with a column containing the average score (average_score) from df1 and df2. df1= data.frame(chrN= c(“chr1”, “chr1”, “chr1”, “chr1”, “chr2”, “chr2”, “chr2”),

I have written a set of functions for POSIXt objects that I would like to offer for consideration for use in base R. They augment and extend existing functions. Briefly, ## pretty.ct function(x,specs=pretty.ct.specs) ## round.ct function(x, tstr='1 min' ) ## axis.ct function(side,x,specs=NULL,...) ## parse.timeint function(dv) ## parse.tstr

Hi all, I would like to know whether there is any function in R were i can find the cross-correlation of two or more multivariate (time series) data. I tried the function ccf() but it seems like to have two univariate datasets. Please let me know. sincerely, sandeep -- Sandeep Joseph PhD Post Doctoral Associate Center for Tropical & Emerging Global Diseases Paul D. Coverdell Center,

All, For data consisting of serial measurements on subjects, one may use the aggregate function to say compute the peak response for each subject for each design condition. Is there a way to alter this or another one-liner to also retain the time at which the peak occurred and thus avoid writing a doing this via a loop? I suppose one could attempt to employ the split function but that's

Follow-up : happy end ... It took quite some thinkering but... i have my data back... I ended up starting without the troublesome zfs storage array, de-installed the iscsitartget software and re-installed it...just to have solaris boot without complaining about missing modules... That left me with a system that would boot as long as the storage was disconnected... Reconnecting it made the boot

Hi, I have a data-matrix: > PID sato hrs fim health 214 3 4.376430 6.582958 5 193 6 4.361825 3.138525 6 8441 6 4.205771 3.835886 7 7525 6 4.284489 3.245139 6 6806 7 4.168926 2.821833 7 5682 7 1.788707 1.212653 7 5225 6 1.651463 1.436980 7 4845 6 1.692710 1.267359 4 4552 5 1.686448 1.220539 6