similar to: AHRQ - Creation of Comorbidity Variables

I apologize if this has been answered. I have researched this to the best of my ability, that's not to say the answer isn't in the archives just I am a new user and I don't know the proper terms to search under. I have an object: f <- mpr100 ~ time + nhb + hispanic + other + rural + hrural + factor(age) + factor(gender) +

I have a function (see below) that does some bootstrapping (I am happy to expand offline why I could use existing functions.) I put my results into and empty matrix and add a row of results with each iteration. My problem is i am a new user to R and I don't understand data frames, matrices, elements, and vectors well. What I would like is to have a data frame I can manipulate outside of the

Dear R-listers, I am an MD and clinical epidemiologist developing a measure of comorbidity severity for patients with liver disease. Having developed my comorbidity score as the linear predictor from a Cox regression model I want to compare the discriminative ability of my comorbidity measure with the "old" comorbidity measure, Charlson's Comorbidity Index. I have nearly 10,000

I am reposting my message from April 8th because I never received a response to the original post: Dear R-listers, I am an MD and clinical epidemiologist developing a measure of comorbidity severity for patients with liver disease. Having developed my comorbidity score as the linear predictor from a Cox regression model I want to compare the discriminative ability of my comorbidity measure with

I downloaded data from http://www.hcp.med.harvard.edu/ncs/ Which provides data in DTA (STATA), XPT (SAS), and POR (SPSS) formats all of which I have tried to read with the foreign package but I am not able to load any of them. I have 2 gb of RAM, but R crashes when the memory gets just over 1 GB. I am using Windows version 2.1.1. The size of the DTA file is 48 MB; the xpt file is 188

Hello, I am new to Scriptaculous, and was recently brought into a project using it to create an email Newsletter builder. The idea is that the user will have lists of elements that he can add to the email page by dragging the element he wants to add from an "available sections" container, to a "loaded sections" container. Dragging from the loaded to available will

Dear R users, For the purpose of validating a prediction model using validate() from the rms package, I am running into some trouble with using the fastbw() function breaking up natural groups of variables. Is there any way I can specify to keep certain variable together? In particular, if interactions are included I would also like to keep the main effects in the model. Another example is a

This looks like a bug to me, except . . . no one else seems to have encountered it, and it's in a pretty basic area, so there must be something wrong at our site. When the Unix server becomes a local master browser, Samba is unable to sync its browse list w/that of the DMB. None of our NT machines are having any trouble, and our tech. support guy says the DMB is in good health. Rebooting

I need some guidance from someone who is familiar/has some experience with the survey package. The data that I am using is from the Medical Expenditure Panel Survey (www.meps.ahrq.gov <http://www.meps.ahrq.gov/> ). The STRATA and PSU variables are varstr01 and varpsu01 respectively. When I try to specify them with the svydesign function I get an error message. An excerpt of my session

Is there any such thing as a program file in R? That is, is it possible to compile and save code for performing data management and analytic tasks for a given project into a single/multiple file(s) (i.e., like a script file (S-Plus), a do file (STATA), or a *.sas file (SAS))? Any words of wisdom or a point in the direction of some documentation would be helpful. If it is not possible to work

Is there any existing function for creating contingency tables that will display counts, row, column, and cell percentages in the same tables....anything similar to crosstabs in S? Marc W. Zodet, MS Health Statistician Center for Cost and Financing Studies Division of Statistical Research and Methods 2101 East Jefferson Street, Suite 500 Rockville, Maryland 20852 Phone: 301-594-7072 Fax:

Is there a way to associate text descriptions with variables in a data.frame? For example... Let's say that in my data.frame I have a variable named var1. var1 represents the responses to the question "When was the last time you saw your physician?" When I tabulate the variable var1 I'd like the output to be a bit more descriptive and contain the more descriptive

Is there a function in R which performs stepwise estimation in ways similar to SAS/STATA (i.e., allows the analyst to specify the significance levels for removal/addition of terms). I've been asked to evaluate two final models: one resulting from a backwards selection in R (stepAIC) and one resulting from a backwards selection using PROC LOGISTIC in SAS. The final terms are slightly

How do I go about generating a WEIGHTED mean (and standard error) of a variable (e.g., expenditures) for each level of a categorical variable (e.g., geographic region)? I'm looking for something comparable to PROC MEANS in SAS with both a class and weight statement. Thanks. Marc [[alternative HTML version deleted]]

If anyone wants to see a prime example of how inefficient it is to program in SAS, take a look at the SAS programs provided by the US Agency for Healthcare Research and Quality for risk adjusting and reporting for hospital outcomes at http://www.qualityindicators.ahrq.gov/software.htm . The PSSASP3.SAS program is a prime example. Look at how you do a vector product in the SAS macro

I'm trying to create a function which will allow me to subset a data set based on values of various specified variables. I also want to then apply some other function(s) (e.g., summary). This is what I've tried so far.... > test.fx <- function(dta, expvar, expval) { + newdta <- subset(dta, eval(expvar)>expval) + summary(newdta$eval(expvar)) + } > >

Here's a patch that should make predict.glm(..., type="response") retain the names. The change passes make check on our Opteron running SLES9. One simple test is: names(predict(glm(y ~ x, family=binomial, data=data.frame(y=c(1, 0, 1, 0), x=c(1, 1, 0, 0))), newdata=data.frame(x=c(0, 0.5, 1)), type="response")) which gives [1]

A few hours ago, I was making a small point on the R-SIG-robust mailing list on the point that ifelse() was not too efficient in a situation where pmax() could easily be used instead. However, this has reminded me of some timing experiments that I did 13 years ago with S-plus -- where I found that pmin() / pmax() were really relatively slow for the most common case where they are used with only

What is the best way to sort a dataframe? For example, how would I go about sorting a dataframe (with variables V1-V5) by ascending V1, V2 and descending V3 while retaining V4 and V5. Also, is there a relatively easy way by which to re-order my columns? Thank you for your time. Marc Marc Zodet [[alternative HTML version deleted]]

Yes, functions like c, min and max are special cases, as they are primitives. For ordinary functions, you just need to promote them with "..." as the signature: setGeneric("pmax", signature="...") setMethod("pmax", "Class", function(..., na.rm=FALSE) { }) One caveat is that all arguments passed via "..." must derive from the class