search for: patids

I can't get the PERL subexpression translated to R. Following, for example, B. Ripley's http://finzi.psych.upenn.edu/R/Rhelp02a/archive/58984.html I am using sub, but it looks like an ugly substitute. Assume I want to extract the first alpha part and the first numeric part, but only if they are in sequence. Do I really have to use the sub twice, first extracting the first variable, then

I was wondering if someone can help me figure out the following: I have two patient datasets, ds1 and ds2. ds1 has fields "patid", "date", and "lab1". ds2 has "patid", "date", and "lab2". I want to find all the patids that have at least 2 dated records for each lab. I started by splitting each dataset by patid, to create ds1.list and ds2.list. Then I did some processing (with sapply) to each list to get the lengths of each patient list item. Then I kind of lost my way and things got messy as I tried to ex...

Dear list member, I have the following data example ke <- data.frame(patid=c(1,1,1,2,3,3),a=c(1,2,2,1,1,2)) I want to add another variable b, such that the max of 'a' by id is returned i.e data ke becomes ke <- data.frame(patid=c(1,1,1,2,3,3),a=c(1,2,2,1,1,2),b=c(2,2,2,1,2,2)) Any help will be appreciated. Oluwakemi [[alternative HTML version deleted]]

Dear R-users! I am using R 1.7.0, under Windows XP. Having some hospital discharge data (admission date and discharge date for each patient), I want to get the number of patients in the hospital on a given date. My data look like (simple example): > x <- data.frame(patid=c("pat1", "pat2"), adm.date = c("15.03.2002", "16.03.2002"),

Dear R-help, Can anyone explain the meaning of the warning, Singular precision matrix in level -1, block 1 ? Or how to track down where it comes from? More precisely, using the nlme package, I'm issued with the warning itt2 <- lme(lrna~rx.nrti+lbrna, random=~1|patid, cor=corExp(form=~days|patid,nugget=T), weights=varPower( form=~lbrna),data=rna3) Warning messages: 1: Singular

I have a dataframe that contains fields such as patid, labdate, labvalue. The same patid may show up in multiple rows because of lab measurements on multiple days. Is there a simple way to obtain just the first and last record for each patient, or do I need to write some code that performs that. Thanks, Steven

Hello, I'm new to R but wan't to use it to compute the statistics of my medical study. The study includes several parameters for a number of patients. Each parameter was assessed by a number of readers, once with a special condition, once without. Now I have a data.frame with colums like: PatientID, ReaderID, SpecialCond(yes/no), Parameter1, Parameter2..... the rows are not sorted, and

I've got a big data.frame from which I need to extract data based on a variable number of Id's (InfCode). Until now I've been using the following dull solution as I never needed to search for more than 5 codes. Now my needs have increased faster than my R skills did and I need to call my function with about 25 values for x. There has to be a *apply or even simpler solution which

We're running a PIII550, 128 MB, 3com 3c905b-TX with SuSE Linux 6.3; Kernel 2.2.14 (see file kernelconfig) and Samba 2.0.6 as PDC & Fileserver in a hospital. Now we got the following error: Feb 18 14:39:54 file kernel: Unable to handle kernel paging request at virtual address 00110004 Feb 18 14:39:54 file kernel: current->tss.cr3 = 040ab000, %cr3 = 040ab000 Feb 18 14:39:54 file kernel: