[R] Table Transformation

[hadley wickham]

On Wed, Mar 4, 2009 at 11:58 AM, Christian Pilger
<christian.pilger at gmx.net> wrote:
>
> Dear R-experts,
>
> recently, I started to discover the world of R. I came across a problem,
> that I was unable to solve by myself (including searches in R-help, etc.)
>
> I have a flat table similar to
>
> key1    key2    value1
>
> abcd_1  BP      10
> abcd_1  BSMP    1A
> abcd_1  PD      25
> abcd_2  BP      20
> abcd_3  BP      80
> abcd_4  IA      30
> abcd_4  PD      70
> abcd_4  PS      N
>
> I wish to transform this table to obtain the following result:
>
>        key2
> key1    BP      BSMP    IA      PD      PS
> abcd_1  "10"    "1A"    ""      "25"    ""
> abcd_2  "20"    ""      ""      ""      ""
> abcd_3  "80"    ""      ""      ""      ""
> abcd_4  ""      ""      "30"    "70"    "N"
>
> I considered "table" and "xtabs" but I could not get the desired result: I
> received cross-tables key1 vs. key2 that contained counts within the cells.
>
> Can anybody help me?

With the reshape package:

cast(mydf, key1 ~ key2)

You can find out more at http://had.co.nz/reshape

Hadley

-- 
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