Not really answering your posed question, but a) reshape2 uses dcast and acast
b) The "cast" step of "melt-cast-melt" can invoke plyr, and it seems like MCM is just a very inefficient way for you to get at the plyr functionality. Perhaps you should take a more direct route to your goal? --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. Johannes Radinger <jradin...@gmx.at> wrote: >Hi, > >I used to use reshape and moved to reshape2 (R 2.15.1). Now I tried >some of my older scripts and was surprised that my cast function wasn't >working like before. >What I did/want to do: >1) Melt a dataframe based on a vector specifying column names as >measure.vars. Thats working so far: >dfm <- melt(df, measure.vars=n, variable_name = "species", na.rm = >FALSE) > >2) Recast the dataframe: >dfc <- cast(dfm, Var1 + Var2 + Var3 + Var4 ~ species,max) # with >reshape >dfc <- dcast(dfm, Var1 + Var2 + Var3 + Var4 ~ species,max) # with >reshape2 > >but then I get (this is new to reshape2!) a warning message: >In .fun(.value[0], ...) : no non-missing arguments to max; returning >-Inf > >The result seems to be similar (but I haven't checked it yet properly)? >A message to ignore? > >I use melt/cast/melt e.g. for multiple measurements (similar name in >one column) to get only one row (one measurement) with e.g. the max >value. Of course during the procedure I can also use cast/melt to drop >columns that are not relevant for further processing. > >/Johannes > >______________________________________________ >R-help@r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.