NEWS.md

In hadley/reshape: Flexibly Reshape Data: A Reboot of the Reshape Package

reshape2 (development version)

reshape2 1.4.4

• Fix R CMD check failure in R-devel.

Version 1.4.3

• Fix C/C++ problems causing R CMD CHECK errors.

• melt.data.frame() throws when encountering objects of type POSIXlt, and requests a conversion to the (much saner) POSIXct type.

Version 1.4.2

• Minor R CMD check fixes for CRAN.

Version 1.4.1

• melt.data.frame() now properly sets the OBJECT bit on value variable generated if attributes are copied (for example, when multiple POSIXct columns are concatenated to generate the value variable) (#50)

• melt.data.frame() can melt data.frames containing list elements as id columns. (#49)

• melt.data.frame() no longer errors when measure.vars is NULL or empty. (#46)

Version 1.4

• dcast() and acast() gain a useful error message if you use value_var intead of value.var (#16), and if value.var doesn't exist (#9). They also work better with . in specifications like . ~ . or x + y ~ .

• melt.array() creates factor variables with levels in the same order as the original rownames (#19)

• melt.data.frame() gains an internal Rcpp / C++ implementation, and is now many orders of magnitudes faster. It also preserves identical attributes for measure variables, and now throws a warning if they are dropped. (Thanks to Kevin Ushey)

• melt.data.frame() gains a factorsAsStrings argument that controls whether factors are converted to character when melted as measure variables. This is TRUE by default for backward compatibility.

• melt.array() gains a as.is argument which can be used to prevent dimnames being converted with type.convert()

• recast() now returns a data frame instead of a list (#45).

Version 1.2.2

• Fix incompatibility with plyr 1.8

• Fix evaluation bug revealed by knitr. (Fixes #18)

• Fixed a bug in melt where it didn't automatically get variable names when used with tables. (Thanks to Winston Chang)

Version 1.2.1

• Fix bug in multiple margins revealed by plyr 1.7, but caused by mis-use of data frame subsetting.

Version 1.2

• Fixed bug in melt where factors were converted to integers, instead of to characters

• When the measured variable is a factor, dcast now converts it to a character rather than throwing an error. acast still returns a factor matrix. (Thanks to Brian Diggs.)

• acast is now much faster, due to fixing a very slow way of naming the output. (Thanks to José Bartolomei Díaz for the bug report)

• value_var argument to acast and dcast renamed to value.var to be consistent with other argument names

• Order NA factor levels before (all) when creating margins

• Corrected reshape citation.

Version 1.1

• melt.data.frame no longer turns characters into factors

• All melt methods gain a na.rm and value.name arguments - these previously were only possessed by melt.data.frame (Fixes #5)

hadley/reshape documentation built on March 16, 2021, 9:38 a.m.