search for: medstats

Displaying 12 results from an estimated 12 matches for "medstats".

2008 Jul 27
0
competing risk model with time dependent covariates under R or Splus
This message was also sent to the MEDSTATS mailing list, so here is the reply I posted to that: Philippe, The machinery to use is to split follow-up time so finely that you can safely assume that rates are constant in each interval, and then just stuff it all into a Poisson model. This allows you to use any kind of time-dependent variable...
2008 Nov 15
3
Statistics forums
Hi, Given that the R forum is mostly a site to discuss issues related to the language, are there any forums that discuss statistical issues? I am specifically interested in the statistical issues in experimental design. TIA, Anjan -- ============================= anjan purkayastha, phd bioinformatics analyst whitehead institute for biomedical research nine cambridge center cambridge, ma 02142
2008 Aug 19
1
variance components
Please forgive the cross posting. I sent this to Medstats and have not received any response. I am looking for a good written explanation of components of variance (a.k.a variance components), in particular as they are used in genetic analyses. Does anyone have a suggestion? I am interested in books, articles and on-line material. I intent to give the ma...
2023 Oct 31
0
Missing shapes in legend with scale_shape_manual
I believe the missing shapes are because you had set alpha=0 for the last geom point. I expect there are better ways, but one way to handle it would be to avoid the filtering, adding columns with med and exercise status, like the following: # setup with data provided Date <- c('2023-10-17', '2023-10-16', '2023-10-15', '2023-10-14',
2023 Oct 31
0
Missing shapes in legend with scale_shape_manual
Tim, thanks, it helps very much. It works like a charm. Wow, there's so much I don't understand about ggplot2 functions, especially the aes() function. I just discovered the ggplot2-book.org site, and I hope to read it slowly and carefully over the next couple of weeks. Thanks again, Tim, for all your help. -Kevin On Tue, 2023-10-31 at 12:35 +0000, Howard, Tim G (DEC) wrote: > I
2009 Oct 01
2
GAM question
Hello evyrone, I would be grateful if you could help me in (I hope) simple problem. I fit a gam model (from mgcv package) with several smooth functions . I don't know how to extract values of just one smooth function. Can you please help me in this? Kind regards, Daniel Rabczenko
2010 Nov 29
1
weighted Spearman correlation coefficient
Hello, I would be grateful if anybody can help me in finding an R function to compute weighted Spearman correlation coefficient? Kind regards, Daniel
2011 Jun 04
1
nonparametric logistic regression based on locally weighted scatterplot smoothing (lowess)
Dear UseRs: Recently, I have read an article regarding the association between age and lymph node metastases. http://jco.ascopubs.org/content/27/18/2931.long In statistical analysis, the authors stated "Because a nonlinear relationship between age and lymph node involvement was expected based on existing literature, lymph node involvement was also regressed on age using nonparametric
2012 May 01
1
testing parallel slopes assumption for Ordinal Logistic Regression
Hi everyone, I'm a bit new here (and new to R), and I was trying to do an OLR, and testing the parallel slope assumption seems be very important. I browsed through past postings, and didn't find much to help me in this area. I was wondering if anyone knew how I could go about doing this. Thank you. -- View this message in context:
2009 Aug 03
1
min frequencies of categorical predictor variables in GLM
Hi, Suppose a binomial GLM with both continuous as well as categorical predictors (sometimes referred to as GLM-ANCOVA, if I remember correctly). For the categorical predictors = indicator variables, is then there a suggested minimum frequency of each level ? Would such a rule/ recommendation be dependent on the y-side too ? Example: N is quite large, a bit > 100. Observed however are
2002 Oct 14
1
Question: concatenating lists
Dear R users, I have the following problem. I have a number of lists with identical structure. Each component is a vector, matrix or array, but components of different lists may be of different size. How do I combine the lists to get a new list such that each component of this list contains the components of the individual lists? An example may explain most clearly what I need. Suppose I have
2010 Dec 28
4
Reading sas7bdat files into R
Hi All, I am trying to import a .sas7bdat file into R. I tried using Hmisc package's sasxport.get() function. temp <- sasxport.get("path\abcd.sas7bdat") I get an error that says "Error in lookup.xport(file) : file not in SAS transfer format" I am not familiar with SAS transfer format. Could somebody please clarify what is it that I am missing, Thanks for your