[R] A way to "lock down" the order of bars for ggplot "dodged"histogram

[ONKELINX, Thierry]

Dear Jason,

Convert Person to a factor with the levels in the order that you want.

Group_df$Person <- factor(Group_df$Person, levels = c("Them", "You", "Me")) 

HTH,

Thierry

----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium 
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be 
www.inbo.be 

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~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Namens Jason Rupert
Verzonden: donderdag 5 februari 2009 17:09
Aan: R-help at r-project.org
CC: ggplot2 at googlegroups.com
Onderwerp: [R] A way to "lock down" the order of bars for ggplot "dodged"histogram

It appears that ggplot reorder the data for a "dodged" histogram based on whether or not a specific variable has a value in the first bin. 
 
I would like to be able to absolutely force the order of the variables in the bin.  For example, say I have three variables Me, You, and Them. 
 
Me_df<-data.frame(Data = c(1:15), Person = "Me")
You_df<-data.frame(Data = c(10:20), Person = "You")
Them_df<-data.frame(Data = c(15:25), Person = "Them")
Group_df_tmp<-rbind(Me_df,You_df)
Group_df<-rbind(Group_df_tmp,Them_df)
counts <- ddply(Group_df, .(cut(Data, breaks=fullseq(range(Data), 5)), Person), nrow) 
names(counts) <- c("Bin", "Person", "Frequency")
qplot(Person, Frequency, data = counts, fill = Person, geom="bar", stat="identity", width = 0.9, xlab="Person") +  facet_grid(. ~ Bin) 
 
However, I absolutely must have the bar order be Them, You, Me.   Is there a to fix the order of the bars so that they are always in the Them, You, Me order? 
 
Thank you again for any feedback you can provide.  
 
 


      
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