Manipulating data matrices

["angela g." <angelaeic@hotmail.com>]

Hi,

 

I am performing survival analysis to compare survival of three groups with the following statement:

 

myfit_survfit(Surv(time, status)~group, data="">

 

"mydata" has a column called "group". There are three different groups: 0, 1 and 2.

 

However, I only want to compare two survival curves at a time (ie. pairwise comparissons: 0 vs 1, 0 vs. 2, 1 vs. 2).

 

1) How do I indicate that to the above command?

2) Is there an easy way (using the command line) to create data subsets of "mydata" that include only two groups ? What I have done thus far, is to create separate datasets, eg. mydata01 which only has group 0 and 1 in it; mydata02 with only group 0 and 2, etc., via the GUI interface but that's turning into a timeconsuming pain. Is there a better, faster way to do this.

 

Any feedback is greatly appreciated. Thanks.

 

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