Question

I have a problem with the reshape function. I tired it for while now, but it just doesn’t work. My data looks like this:

    KeyItem    Year    Value
    Income     2011     10000
    Income     2010     29299
    Depth      2010     29393
    Market Cap 2010     39393
    Depth      2011     20000
    Market Cap 2011     30000

and I need it to look like this for my function:

   KeyItem        2011         2010
   Income         10000        29299
   Depth          20000        29393
   Market Cap     30000        39393

Answer 1

The easiest way is to use the dcast function in the reshape2 package. First, load in the data:

dd = read.table(textConnection("KeyItem Year Value
Income 2011 10000
Income 2010 29299
Depth 2010 29393
Market 2010 39393
Depth 2011 20000
Market 2011 30000"), header=TRUE)

then load the package:

library(reshape2)

Finally, just the dcast function:

dcast(dd, KeyItem ~ Year)

to get:

R> dcast(dd, KeyItem ~ Year)
Using Value as value column: use value.var to override.
  KeyItem  2010  2011
1   Depth 29393 20000
2  Income 29299 10000
3  Market 39393 30000

To go the other way, just use the melt function:

melt(dcast(dd, KeyItem ~ Year))

---

You can reorder your columns in the usual way:

dd1 = dcast(dd, KeyItem ~ Year) 
dd1[,c("KeyItem", sort(colnames(dd1[, 2:ncol(dd1)]),TRUE))]