[R] matching by gender and age

[David Winsemius]

On May 26, 2011, at 11:19 AM, 1Rnwb wrote:

> Hello R gurus, I have a data set from which i have to extract the  
> gender and
> age matched rows from controls and disease group

You need to define what you mean by "age-matched". Your example  
creates a very narrow age range which further adds questions about  
what you are doing. You probably need to look at defining an age- 
category variable with cut() and proceeding from there.


> disease<-paste(rep(c('y','n'),11))
> gender<-paste(rep(c('m','f'),11))
> mcp<-rnorm(700,1400)
> age<-rnorm(32,34)
>
> dat<- 
> data.frame(disease=disease,sex=gender,Dr_age=age[1:22],MCP=mcp[1:22])

Use set.seed to generate a reproducible input and then tell us what  
your expected output should be.

>
> I have other categorical variables also to add to the matching. all  
> the
> posts I came across are matching for a single column from two
> matrix/dataframe. How can i match for multiple variables when all  
> the data
> is in one single dataframe
>


David Winsemius, MD
West Hartford, CT