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I was wondering whether there is a command in R similar to the '!' command in unix. Thanks Neil

Hi, I was wondering how I would recode a variable as being NA (or missing). Thanks Neil

Hi, Is it possible to add labels to variables in R (so as to have a better description of what the variables represent)? Thanks, Neil

Hi, Does anybody know if it is possible to have keyboard input into functions? Kind of like 'scanf()' in C. I want to write a function that asks me what to put in certain variables. Thanks, Neil

Hi, Can anybody tell me what the message below means and how to overcome it. Thanks, Neil Warning message: X matrix deemed to be singular; variable 2 in: coxph(Surv(age_at_death, death) ~ project$pluralgp + project$yrborn + ......... >

I'm having a bit of trouble recoding factors in a fields. I have a field which has the factors Singleton, Twin and Triplet. I want to recode the field to have only the factors Singleton and Multiple. Any advice...

I think this is a pretty basic statistic question: If I have a variable which has 4 factors how can I add it to a coxph model? I have other variables added which have digits 1-4 instead of four...

Hi, I have imported some data to R from stata and my factor variables have an Indeterminate level which I don't really want. For example the variable sex has the levels Male, Female and Indeterminate. There are no 'Indeterminate...

Hi, I am trying to compute a table of a Kaplan Meier survival function. I have created the Kaplan Meier using: field.KM <- survfit(Surv(project_no_1983$entryage3,project_no_1983$age_at_death,proj ect_no_1983$death...

Hi, I have a data frame which contains two fields, 'prev' and 'mchnum'. I have another data frame which also contains 'mchnum' and 'prev' and some other fields. The 'prev' data in this field is corrupted and I want to...

I want Twin and Triplet to both be recoded as Multiple Neil On 18/10/2004, at 7:43 PM, Uwe Ligges wrote: > Neil Leonard wrote: > >> I'm having a bit of trouble recoding factors in a fields. >> I have...

Hi, I'm trying to print the p-values from the output of a CPH test onto a Kaplan Meier plot. Can this be done? I only really want the p-values from the CPH test to appear but if...

Yes that's it. Thanks Neil On 18/10/2004, at 7:57 PM, Prof Brian Ripley wrote: > On Mon, 18 Oct 2004, Uwe Ligges wrote: > >> Neil Leonard wrote: >> >>> I'm having a bit of trouble recoding factors in a...

Sorry, I meant putting missing values into a variable. Thank you for your help. Neil On 30/10/2004, at 3:10 PM, <Bill.Venables at csiro.au> wrote: > Would you care to be a bit more explicit? > > If you...

Hi, I'm having a bit of trouble with using StepAIC with a coxph model. Can anybody tell me if there is anything wrong with what I am doing here (I've removed a few of the variables for the...

This is the output. I think it means that there is a problem with project$pluralgpTriplet??? Neil > fm.CPH Call: coxph(formula = Surv(age_at_death, death) ~ project$pluralgp + project$yrborn + project$private + project$pcdead + project$mheight + project$ga2 + project...