ggplot2 geom_bar中的bar宽度

I am trying to produce plots with a loop.

我正在尝试用一个循环来制作情节。

l1<-factor(rep(letters,4))
n1<-abs(rnorm(104))*10000
b1<-rep(c("1","2","3","4","5","6","7","8"),c(2,2,11,24,11,20,33,1))
k1<-rep((rep(c("A","B","C","D"),c(2,3,4,4))),8)
my.df<-data.frame(l1,b1,k1,n1)                            #make a dataframe

names(my.df)<-c("letter","branch","ltrtype","number")     #factor names
library(ggplot2)

branch.list<-unique(my.df$branch)
sayi<-length(branch.list)                                 # list of factor:letters

for (i in 1:sayi) {

branch.iter<-branch.list[i]
my.df.plot<-subset(my.df,my.df$branch==branch.iter,drop=T)

my.df.plot$branch<-factor(my.df.plot$branch)               #So that unused levels don't show up
my.df.plot$letter<-factor(my.df.plot$letter)               #So that unused levels don't show up
my.df.plot$ltrtype<-factor(my.df.plot$ltrtype)             #So that unused levels don't show up
my.df.plot$number<-as.numeric(as.character(my.df.plot$number))
my.df.plot<-data.frame(my.df.plot)

myfilename<-paste(branch.iter,".jpeg",sep="")
jpeg(file=myfilename)

cizim<-ggplot(my.df.plot,aes(letter,number,fill=ltrtype))
cizim<-cizim + geom_bar(width = 1, position = "fill", binwidth = 1) +     facet_grid(ltrtype~.)
cizim<-cizim + opts(title=branch.iter)

print(cizim)
dev.off()

}

(Q1): When number of levels in x-axis change width of bars change How can i prevent this and make bar width in every plot same?

(Q1):当x轴上的层数改变条宽时，如何防止这种情况的发生，使每一块地块上的条宽相同?

alt text http://img411.imageshack.us/i/95325388.jpg/

alt文本http://img411.imageshack.us/i/95325388.jpg/

alt text http://img411.imageshack.us/i/91510133.jpg/

alt文本http://img411.imageshack.us/i/91510133.jpg/

(Q2): when i=7 R gives following warning:

(Q2):当i= 7r时，发出以下警告:

(data$ymin == 0)) warning("Filling not well defined when ymin != 0") : missing value where TRUE/FALSE needed

(数据$ymin = 0)警告(“当ymin != 0时填充定义不明确”):需要TRUE/FALSE时缺失值

what can i do about it?

我该怎么办呢?

(Q3): Is there an easier way to drop unused levels in such a case so i don't have to use

(Q3):在这样的情况下，是否有更容易的方法来删除未使用的级别，这样我就不用使用了。

 my.df.plot$branch<-factor(my.df.plot$branch)

everytime?

每一次?

2 个解决方案

#1

You are producing some very strange plots. By using position="fill" you are stretching out each bar to have height 1 (because the one observation corresponding to the letter is 100% of all observations corresponding to the letter within a panel), completely loosing whatever information you are trying to plot. My guess is that some of your questions stem from this mistake, but I am not sure.

你在创作一些非常奇怪的情节。通过使用position="fill"，你可以将每条线展开，使其具有1的高度(因为对应于字母的一个观测值是面板中对应于字母的所有观测值的100%)，完全失去了你想要绘制的任何信息。我猜你的一些问题源于这个错误，但我不确定。

(Q1) Do you want the bar width to be the same in plots for the different branches? Since you are changing the number of levels of the x variable, the bars have to get wider to fill up the plot. Some solution options:

(Q1)你是否希望不同分支的条形宽度相同?因为你在改变x变量的等级，条形必须变宽才能填满整个图。一些解决方案选择:

Do some smart resizing of the width of the plot to go around that.
做一些巧妙的调整，以改变情节的宽度。
Leave all the x levels in - I think this is the cleanest way
把所有的x层都放进去，我认为这是最干净的方法
You can get your bars narrower and centered on the plot by using the expand option of scale_x_discrete. So if you have N total x-values (here N=26 letters), but a particular plot only uses k of them, then add + scale_x_discrete(expand=c(0.05, (N-k)/2)) to your plot. The first term is a multiplicative expansion factor, and this is the default value, and the second term is an additive factor.
通过使用scale_x_discrete的展开选项，可以使条形图更窄、更集中。如果你有N个总x值(这里N=26个字母)，但是一个特定的图只使用其中的k个，然后在你的图中添加+ scale_x_discrete(expand=c(0.05， (N-k)/2))第一项是乘法扩张因子，这是默认值，第二项是加性因子。

(Q2) i=7 is the only group that has multiple number values corresponding to the same letter/ltrgroup combination. The bar geom does not know what to do with that. I agree that the error message is really cryptic.

(Q2) i=7是唯一一个具有相同字母/ltrgroup组合对应的多个数值的组。bar geom不知道该怎么做。我同意错误消息是非常神秘的。

(Q3) One option is to avoid using factors - use data.frame(...,stringsAsFactors=FALSE) when combining character vectors, and then subsetting will not keep unused levels around.

(Q3)一种选择是避免使用因子——组合字符向量时使用data.frame(…，stringsAsFactors=FALSE)，然后子设置将不会保留未使用的级别。

#2

(Q1) I don't think it is possible to fix bar width. Aniko's suggestion to keep all the levels makes most sense to me.

(Q1)我认为不可能固定bar的宽度。对我来说，Aniko保持所有水平的建议最有意义。

(Q2) replace binwidth = 1 with stat="identity", as I don't think you need stat="bin".

(Q2)将binwidth = 1替换为stat="identity"，因为我认为您不需要stat="bin"。

(Q3) Other options include drop.levels in gdata-package, and dropUnusedLevels in Hmisc-package.

(Q3)其他选项包括drop。gdata包中的级别，Hmisc-package中的dropunusedlevel。

#1