Flexibly Reshape Data

Flexibly restructure and aggregate data using just two functions: melt and cast.


Reshape 0.8.6 ------------------------------------------------

  • fix outstanding R CMD check problems

Reshape 0.8.5 ---------------------------------------------------

  • fix outstanding R CMD check problems

Reshape 0.8.4 ---------------------------------------------------

  • fix spelling mistake (indicies -> indices), thanks to Stavros Macrakis

Reshape 0.8.3 (2009-04-27) ---------------------------------------------------

  • better rename example
  • When removing missing values in melt, look only at measured variables, not id variables
  • Fixes to documentation bugs revealed by new parser

Reshape 0.8.2 (2008-11-04) --------------------------

  • fixed bug where missing fill values where not getting correctly filled

  • fill value defaults to fun.aggregate applied to zero-length vector. This produces better values in a wide variety of situations, for example missings will be filled with 0's when length or sum is used. This may require setting fill = NA for aggregation functions that previously return NA, like sd and var.

Reshape 0.8.1 (2008-05-01) --------------------------


  • character dimension names are processed by type.convert
  • by default, treat character and factor variables as id variables (i.e. integer variables no longer default to being id vars)
  • ... now passed on to melt in melt.list (thanks to Charles Naylor)


  • missing values in subsetting are now correctly dropped to match behaviour of subset()
  • tweaks to cast and recast to make it easier to pass in formulas created elsewhere
  • allow user to specify column used for values, guessing if necessary, and giving a warning message if value column does not exist
  • improve error messages when melt or casting parameters incorrectly specified


  • now depends on the new plyr package for many of the workhorse functions

Reference manual

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