[BioC] Survival analysis (hazard ratio calculation)

[Farscape2012]

Hi,

I have been trying to compute hazard ratio between groups. I failed to 
find similar examples.

I have data like this:
      status time group
1    LIVING   14     1
2    LIVING   44     5
3  DECEASED   32     4
4    LIVING    8     7
5    LIVING   19     4
6    LIVING   22     4
7    LIVING   63     6
8    LIVING   44     3
9    LIVING   25     3
10   LIVING   60     3
11 DECEASED   25     4
12   LIVING   62     2
13   LIVING   43     6
14   LIVING   42     6
15   LIVING   44     2
16   LIVING   21     4
17   LIVING   26     4
18   LIVING   25     4
19   LIVING   24     3
20   LIVING   16     1

I have successfully plotted kaplan meier curve for each group. Now I 
want to compute hazard ratio between the groups.  The result could be 
like a symmetric matrix.  Each entry Eij shows the hazard ratio between 
group i and group j.

How can I do this? Please help me.

Br,
Luffy