similar to: Stats question: Comparison of the same individuals during two exposure times

Displaying 20 results from an estimated 1000 matches similar to: "Stats question: Comparison of the same individuals during two exposure times"

2011 Oct 05
2
Subsetting a data frame with multiple values and exclusions.
Hi all, I realise that the convention is to provide a working example of my problem but the data are of a sensitive nature so I'm not able to do that in this case. I need to query a database for multiple search terms: db <- structure(list(ind = c("ind1", "ind2", "ind3", "ind4"), test1 = c(1, 2, 1.3, 3), test2 = c(56L, 27L, 58L, 2L), test3 =
2011 Mar 10
2
within group sequential subtraction
Hi Everyone, I would like to do sequential subtractions within a group so that I know the time between separate observations for a group of individuals. My data: data <- structure(list(group = c("IND1", "IND1", "IND2", "IND2", "IND2", "IND3", "IND4", "IND5", "IND6", "IND6"), date_obs =
2011 Dec 05
1
Subsetting a data frame
Hi R users, I really need help with subsetting data frames: I have a large database of medical records and I want to be able to match patterns from a list of search terms . I've used this simplified data frame in a previous example: db <- structure(list(ind = c("ind1", "ind2", "ind3", "ind4"), test1 = c(1, 2, 1.3, 3), test2 = c(56L, 27L, 58L,
2011 Mar 09
2
Cleaning date columns
Hi Everyone, I have the following problem: data <- structure(list(prochi = c("IND1", "IND1", "IND1", "IND2", "IND2", "IND2", "IND2", "IND3", "IND4", "IND5"), date_admission = structure(c(6468, 6470, 7063, 9981, 9983, 14186, 14372, 5129, 9767, 11168), class = "Date")), .Names =
2010 Mar 12
7
sqldf not joining all the fields
Dear R users, I have two data frames that were read from text files as follows: x_data <- read.table("x.txt", header = TRUE, sep = "|", quote = "\"'", dec = ".",as.is = TRUE,na.strings = "NA",colClasses = NA, nrows = 3864284, skip = 0, check.names = TRUE,fill=TRUE, strip.white = TRUE,
2011 Jul 25
1
Cox's regression analysis with Left truncated data
Hi, I have a fairly simple question. I would like to use the survival package to perform an analysis on data where an event can have occurred before individuals were recruited into a study. I'm not sure how to do this using the Surv() function. I would have a date of an event and then the enrolment date would be after that. How do I put these two dates into the survival function? Thank
2010 Feb 20
3
Rearranging a data frame for multiple observations
Hi there, I think I'm struggling with a fairly simple problem but can't seem to solve it. I have multiple observations for one unique identifier. Ultimately I want to end up with one line per identifier with multiple observations in rows. I'm really stuck any help would be really appreciated. CAO0337134 05/09/95 CAO0337134 27/09/05 CAO0347741 10/10/04 CAO0347741 12/10/04
2010 Mar 03
1
Subset using partial values
Hi everyone, I would like to subset a data.frame using partial values. For example I have the following data.frame: PROCHI Main_condition 1234 411 1235 4110 1236 4111 1237 I20 1238 I201 1239 I202 Now let's say that I use the Subset function. Ordinarily I would use it as follows Subset(x, Main_condition=="411"|Main_condition=="4110" etc to get
2010 Sep 06
3
Finding the two most recent dates
Dear R help, I have the following data frame: structure(list(prochi = c("ind_1", "ind_1", "ind_1", "ind_1", "ind_1", "ind_1", "ind_1", "ind_1", "ind_1", "ind_1"), date_1st_event = structure(c(14784, 14784, 14784, 14784, 14784, 14784, 14784, 14784, 14784, 14784 ), class = "Date"),
2010 Mar 15
1
inner join sqldf
Hi, I have two dataframes that have some common columns. I would like to join them by the common columns prochi and prescribed_date as there are duplicate prochis but they will be made unique by date. I tried doing an inner join but that just duplicated the columns whereas I would like the information from the test_sql_tsf to fill the NAs in the test_sql_psd common columns. require(sqldf)
2012 Sep 13
1
[LLVMdev] Parsing C++ template parameters using cindex.py
Hi, I am parsing a C++ file using cindex.py and want to get the template parameters to a specific node. However, the tree seems to be different depending on if the template parameter is a struct/class or a simple type such as int or float. In the first case the template type is appended as a child to the VAR_DECL node (the TYPE_REF node seen in the example below), but this is not the case with
2001 Jul 25
2
using compiled fortran in R
Hi, I would like to use a Fortran subroutine in R. I have checked the R docs and Newsletter, but..., I am unable to load an object file into R. The steps I have taken are (on Debian Linux/recent Intel-type chip ): 1. g77 -c hello.f to create hello.o 2. mymachine> R to start R 3. > dyn.load("hello.o") at which point I am getting the error msg: Error in
2003 Apr 18
1
stepwise discriminant analysis
Hi all, is it possible to do stepwise discriminant analysis (linear amnd non-linear) in R? If yes- which package does it|? Thanks Janine -------------------------------------------- "El gesto y la palabra son el pensamiento del hombre" Isabel Allende Janine Illian lecturer in statistics SIMBIOS School of Computing University of Abertay Dundee Bell Street Dundee, DD1 1HG Scotland,
2003 Jul 14
1
bootstrapping the lme model
Dear all, I have a data set o which I'd like to fit lme model. There are three factors one of whoich is nested. This should be easy to do using lme in R, but the problem ist that the data is highly non-normal. I was thinking about bootstrapping the distribution but don't have much experience of doing this in R and most references I find don't seem to go beyond the
2008 Sep 29
1
Located Latent Class Analysis (Uebersax)
Dear list members I am new to the list and would be much appreciated if you could help me. I am very interested in applying Latent Class Model for analysing multiple raters agreement data. I have recently found a paper by Uebersax, J. (1993) which described a method in a form of Located Latent Class Analysis (llca). Uebersax has written a Fortran program which is available on the web, for the
2010 May 07
2
glm contrasts
Hi, I have some data on the effect of cycle shape (categorical) and frequency (continuous) on the efficiency of muscle contraction. My minimum adequate model is: m15<-glm(efficiency~cycle.shape*freq, family=quasipoisson) However, I wish to know where significant differences lie between specific combinations of treatments. I guess I want an equivalent of a post hoc test following an
2006 Dec 04
2
Nested for loop
Hi all, Does anybody know whether one can nest IF statement in multiple FOR loops ? According to results of my code, only the first iteration of each loop is performed... Thanks, Regards, Natalie [[alternative HTML version deleted]]
2011 Jun 14
0
[LLVMdev] Reading Instructions from Ocaml
On Mon, Jun 13, 2011 at 12:09 PM, Gregory Malecha <gmalecha at gmail.com> wrote: > Hello, Hello Gregory, > I'm interested in the OCaml bindings, but I've been digging through them and > it doesn't seem possible to actually write a transformation with them. > Specifically, there are a lot of functions to build each type of > instruction, but there doesn't seem
2011 Dec 09
2
Error using function MVN in package MCLUST: Fortran symbol name not in DLL for package
Hi All, I need to fit a mutlivariate normal model to a dataset in order to obtain the mean and covariance parameters. I see that the MVN function in the MCLUST package can do this, however when I try to run even the simplest example provided in the documentation, as below, I get the following error: n <- 1000 set.seed(0) x <- rnorm(n, mean = -1, sd = 2) mvn(modelName = "X", x)
2010 Sep 21
2
General Alawar games issue
See bug 23374. Originally, this was an issue raised for one particular game. But my experiences with other games from the same company indicate that this may be a more widespread problem for their games. The original poster tried one of their "Strange Cases" games. I've tried a "Natalie Brooks" and an "Alabama Smith" adventure. Each keeps coming up with the