[R] how to transform a data file

[Jeff Newmiller]

library(reshape2)
# sample data because you didn't provide any
dta <- as.data.frame( matrix( sample( 0:1, 100, replace=TRUE ), ncol=10 ) )
dta <- cbind( IDN=1:10, dta )
# The command you couldn't figure out
meltdta <- melt( dta, "IDN" )
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Sent from my phone. Please excuse my brevity.


pat j <pjsleuth at gmail.com> wrote:

>Hello R people,
>
>I have a data file with 101 numeric variables: one variable called IDN
>(the
>individual's unique id number, which I need to retain, and which ranges
>from 1000 to 1320; some numbers are obviously skipped), and V1 to V100
>(each has a value of 0 or 1; these 100 variables represent sequentially
>ordered days and whether a characteristic was present or absent--e.g.,
>v1
>is day 1 and a "1" means the characteristic is present; v10 is day 10
>and
>"0" means the characteristic is absent).
>
>This may be child's play for many on this list, but how do I transform
>this
>data file to two columns, one called "id"  and another column named "c"
>with 100 rows? I think it will end up being a 1000 row file. I've read
>some
>and think that I'm trying to "melt" my existing data. I can transpose
>the
>v1 to v100 with t(v1 to v100) but then I'm unclear on how to
>automatically
>generate 100 identical IDN's for each case and variable and then put
>them
>together.
>
>This may be redundant, but for the sake of clarity, what I'm trying to
>do
>is get from this:
>
>IDN      V1 V2 V3 � V100
>
>1       0   1   0  . . .       1
>
>2       1  1   1   . . .       0
>
>4        0  1   0   . . .      1
>
>.
>
>.
>
>100   0  1   0   . . .       1
>
>To this:
>
>id   c
>
>1    0
>
>1    1
>
>1    0
>
>.      .
>
>.    [continue 96 more times for c4 - c100]
>
>1     1
>
>2     1
>
>2     1
>
>2     1
>
>.       .
>
>. [continue 96 more times for c4 - c100]
>
>2     0
>
>.
>
>.
>
>.
>
> [then repeat this for the next 98 cases]
>
>100    0  1   0              1
>
>
>    Thank you very much.
>
>PJ
>
>	[[alternative HTML version deleted]]
>
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