[R] sorted reshaping?

[Gabor Grothendieck]

This also works (giving a matrix so use as.data.frame if you want it
as a data frame):

> tapply(dat.long[,3], dat.long[1:2], c)
    year
firm        2002        2003       2004       2005        2006
  0           NA          NA  1.0000000         NA          NA
  1   0.86456075 -1.06794272  1.1850129 -0.1385206 -0.41101249
  2   0.04505626  0.24331227 -0.7902969  0.6833840  0.17823240
  3  -2.07018155  0.32203467 -1.0867019  1.1990902 -0.86256005
  4  -1.04872782 -0.90006314  1.0398810 -0.3545491 -0.93241925
  5  -1.55728162  0.98297102  1.0280005  1.6397312  0.79278075
  6   0.21446824  0.10913775  1.1284486 -0.4148321  0.95917517
  7  -1.97895845 -0.05366712  0.9740745  0.8070221  1.33701029
  8  -1.94635463 -1.03172741  1.5351331 -2.0643955  0.63561387
  9  -0.08866245  0.42450753 -0.8108118  0.5155799 -1.54716628
  10  0.11008895  0.18344337  0.3891310  0.9016668  0.04618046


On Sat, Jan 23, 2010 at 8:25 AM, ivo welch <ivowel at gmail.com> wrote:
> thank you, dennis.  your example was much better than my own, too.
>
> for everyone else's benefit who will be searching for the answers for
> this problem on r-help, let me extend this a little.   the problem
> arises primarily in data sets that are sparse.  in my case, the first
> (ordered) firm does not have data in the first (ordered) year.
>
>> firm <- c(0,rep(1:10, each = 5))
>> year <- c(2004,rep(2002:2006, 10))
>> resp <- c(1.0,rnorm(50))
>> dat.long <- data.frame(firm = firm, year = year, resp = resp)
>> dat.wide <- reshape(dat.long, direction = 'wide', idvar = 'firm', timevar= 'year')
>> head(dat.wide)
>
> yields
>
>   firm resp.2004 resp.2002 resp.2003 resp.2005 resp.2006
> 1     0    1.0000        NA        NA        NA        NA
> 2     1   -0.4483   -0.7623    1.0625    0.4654  -0.36041
> 7     2   -0.1373   -0.8648    0.7272    0.1637  -0.09235
> 12    3    1.0835    0.4544    0.1577   -1.6991  -1.04559
> 17    4    1.1390    2.1633   -1.2298    0.9460  -0.28682
> 22    5   -0.8906    1.0084   -0.1948   -0.6801  -0.47192
>
>
> in contrast, the library(reshape) function did yield the desired order:
>
>> library(reshape)
> Loading required package: plyr
>> dat.cast <- cast(dat.long, firm ~ year)
> Using resp as value column.  Use the value argument to cast to
> override this choice
>> head(dat.cast)
>  firm    2002    2003    2004    2005     2006
> 1    0      NA      NA  1.0000      NA       NA
> 2    1 -0.7623  1.0625 -0.4483  0.4654 -0.36041
> 3    2 -0.8648  0.7272 -0.1373  0.1637 -0.09235
> 4    3  0.4544  0.1577  1.0835 -1.6991 -1.04559
> 5    4  2.1633 -1.2298  1.1390  0.9460 -0.28682
> 6    5  1.0084 -0.1948 -0.8906 -0.6801 -0.47192
>
>
> I think this example would make a nice addition to "?reshape".  for
> "see also", I would add library(reshape).  finally, it would be nice
> if an email would be on each R help (in R documentation) to make
> suggestions for improvements.
>
> regards,
>
> /iaw
> ----
> Ivo Welch (ivo.welch at brown.edu, ivo.welch at gmail.com)
>
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