reshape -> reshape 2: function cast changed?

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?
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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

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HI,

I tried with an example.? It looks like I am also getting the same error.? I am using R 2.15. 


dfm<-data.frame(Var1=rnorm(10,25),Var2=rnorm(10,15),Var3=rnorm(10,3),Var4=runif(10,0.4),Species=sample(LETTERS[1:4],10, replace=T))
dfmmelt<-melt(dfm,id="Species",na.rm=FALSE)
dcast(dfmmelt,variable~Species,max)
? variable????????? A????????? B????????? C????????? D
#1???? Var1 25.8125354 24.1405082 26.9989409 24.7531392
#2???? Var2 15.5994468 13.8675085 16.5900085 16.4408974
#3???? Var3? 3.4704755? 4.6132785? 5.4582037? 1.7146692
#4???? Var4? 0.8861144? 0.9551669? 0.9641575? 0.4398574
Warning message:
In .fun(.value[0], ...) : no non-missing arguments to max; returning -Inf


Then, I did traceback()

?options(warn=2)

dcast(dfmmelt,variable~Species,value.var="value",max)

Error in .fun(.value[0], ...) : 
? (converted from warning) no non-missing arguments to max; returning -Inf

traceback()

7: doWithOneRestart(return(expr), restart)
6: withOneRestart(expr, restarts[[1L]])
5: withRestarts({
?????? .Internal(.signalCondition(simpleWarning(msg, call), msg, 
?????????? call))
?????? .Internal(.dfltWarn(msg, call))
?? }, muffleWarning = function() NULL)
4: .signalSimpleWarning("no non-missing arguments to max; returning -Inf", 
?????? quote(.fun(.value[0], ...)))
3: vaggregate(.value = value, .group = overall, .fun = fun.aggregate, 
?????? ..., .default = fill, .n = n)
2: cast(data, formula, fun.aggregate, ..., subset = subset, fill = fill, 
?????? drop = drop, value.var = value.var)
1: dcast(dfmmelt, variable ~ Species, value.var = "value", max)

The output seems to be correct.


A.K.



----- Original Message -----
From: Johannes Radinger <JRadinger at gmx.at>
To: r-help at r-project.org
Cc: 
Sent: Wednesday, July 25, 2012 6:14 AM
Subject: [R] reshape -> reshape 2: function cast changed?

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 at 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.