[R] The variables combined in a table from other table and combination questions

[leeznar at yahoo.com.tw]

Dear All:
I need to have some data frame objects.
First aa object:
   pH  Formulation  time  Subject
[1]1.2  F           0       1
[2]7.4  S           1       2
[3]    MF           2       3
[4]                 3       4
[5]                 n        i
Then, I need to produce 2*3(pH*formulation) different 
tables.  This table includes column of (pH,
Formulation, time  S1  S2  S3 ¡K..Si) and S1= subject
1, S2=subject 2 and so on.  For example: bb1 table
   pH  Formulation  time  S1  S2  S3¡K.Si
[1]1.2  F           0       
[2]                 1       
[3]                 2       
[4]                 3       
[5]                 n       

For example: bb2 table
   pH  Formulation  time  S1  S2  S3¡K.Si
[1]1.2  S           0       
[2]                 1       
[3]                 2       
[4]                 3       
[5]                 n       


Moreover, the values of pH and Formulation column are
the combination questions.  The values of pH and
Formulation column should be the combinations such as
(1.2, F), (1.2, S), (1.2, MF), (7.4, F), (7.4, S),
(7.4, MF)
I am a beginner level in R and I have no idea how to
do this. Could any one please help me.  Thanks a
lot!!!

Best regrards
Hsin Ya Lee