[R] transpose? reshape? flipping? challenge with data frame

[Patrick Hausmann]

Hi David,

you could use a mix of "plyr" and reshape:

# Example datasets
# Input
propsum <- data.frame(coverClass=c("C", "G", "L", "O", "S"),
                       R209120812=c(NA, 0.49, 0.38, 0.04, 0.09),
                       R209122212=c(0.05, 0.35, 0.41, 0.09, 0.10))

library(plyr)
xpropsum <- melt(propsum, id.var="coverClass", variable_name = "Image")
tpropsum <- reshape(xpropsum, timevar="coverClass", idvar="Image", 
direction="wide")
colnames(tpropsum) <- sub("value.", "", colnames(tpropsum))
tpropsum

Cheers
Patrick

Am 23.04.2010 06:43, schrieb David.Gobbett at csiro.au:
> Greetings all,
>
> I am having difficulty transposing, reshaping, flipping (not sure which) a data frame which is read from a DBF file.  I have tried using t(), reshape() and other approaches without success. Can anyone please suggest an way (elegant or not) of flipping this data around ?
>
> The initial data is like propsum (defined below), and I want it to look like tpropsum once reformed.
>> propsum
>    coverClass R209120812 R209122212
> 1          C         NA       0.05
> 2          G       0.49       0.35
> 3          L       0.38       0.41
> 4          O       0.04       0.09
> 5          S       0.09       0.10
>
>> tpropsum
>         Image    C    G    L    O  L.1
> 1 R209120812   NA 0.49 0.38 0.04 0.09
> 2 R209122212 0.05 0.35 0.41 0.09 0.10
>
> # Example datasets
> # Input
> propsum<- data.frame(coverClass=c("C", "G", "L", "O", "S"),
>                        R209120812=c(NA, 0.49, 0.38, 0.04, 0.09),
>                        R209122212=c(0.05, 0.35, 0.41, 0.09, 0.10))
>
> # Desired output
> tpropsum<- data.frame(Image=c("R209120812", "R209122212"),
>                        C=c(NA, 0.05),
>                        G=c(0.49, 0.35),
>                        L=c(0.38, 0.41),
>                        O=c(0.04, 0.09),
>                        L=c(0.09, 0.10))
>
> Thanks,
> David
>
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>
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