[R] Columnwise Alternate Subsetting of a Data Frame

Gundala Viswanath gundalav at gmail.com
Mon Jun 23 05:03:25 CEST 2008


Given this data frame:

> print(repo.dat)
                               V1             V2      V3      V4
      V5   .... (can be more)
1      1007_s_at   DDR1  2865.1  2901.3  1978.3   300.2
2       1053_at      RFC2   103.6    81.6   108.0          101.3

I want to split them into two data frames yielding:

                               V1             V2         V3      ... etc
1      1007_s_at   DDR1  2865.1    1978.3
2       1053_at      RFC2   103.6      108.0

(V2 and V3 is obtain from V2 and V4 of original repo.dat)


                               V1                V2           V3   ...etc
1      1007_s_at   DDR1    2901.3     300.2
2       1053_at      RFC2      81.6        101.3

(V2 and V3 is obtain from V3 and V5 of original repo.dat)

In principle what we desire to do is to:
1. Given original data frame with V1, V2, V3, V4....
2. Split the data frame into two based on V2,V4,V6 ... (even) and V3,
V5, V7 ..(odd) in the original data frame
3. Meanwhile keep row names and V1 in two newly formed data frames.

Is there a compact way to do it?

- Gundala Viswanath
Jakarta - Indonesia

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