关于ggplot改变背景报错的问题

今天打算画一个barplot，然后加上方差，后来想要把背景去掉，加上theme主题，结果发现总会报错，Error in inherits(x, “theme”) : argument “e2” is missing, with no default
搞了两个小时，终于发现错误的原因并不是网页上说的加号太多了，需要写到一起去，而是需要分开写才可以，下面将把具体代码演示如下，如果小伙伴遇到类似问题，可以参考一下。

数据结构

ID Symbol sunlight control
1 L1 1.8092 3.54
2 I2 27.3529 4.408
3 G 1.4845 0.7348
4 5G 32.0455 57.7454
5 ST 19.6581 4.8752

执行代码

library(ggplot2)
library(plyr)
library(reshape2)

data<-read.csv(“rnaseq.csv”,header=TRUE)
melted <- melt(data, id.vars=c(“ID”, “Symbol”))
value_log<-log(melted$value,2)
melted<-cbind(melted,value_log)
means <- ddply(melted, c(“Symbol”, “variable”), summarise,
mean=mean(value_log))

===================================
means.barplot <- qplot(x=Symbol, y=mean, fill=variable,
data=means, geom=”bar”, stat=”identity”,
position=”dodge”,ylab=”log(Mean Expression of genes)”)
means.barplot +
theme(panel.background = element_rect(fill = “transparent”, color = “gray”),
legend.key = element_rect(fill = “transparent”, color = “transparent”),
axis.text = element_text(color = “black”))

===========这样操作不会出现错误============

####################下面引入方差项=========

means.sem <- ddply(melted, c(“Symbol”, “variable”), summarise,
mean=mean(value_log), sem=sd(value_log)/sqrt(length(value_log)))
means.sem <- transform(means.sem, lower=mean-sem, upper=mean+sem)

means.barplot + geom_errorbar(aes(ymax=upper,
ymin=lower),
position=position_dodge(0.9),
data=means.sem)
==================这样也不会报错=================
但是，如果执行如下代码，即同时加上方差项和把背景改为白色就会报错
means.barplot + geom_errorbar(aes(ymax=upper,
ymin=lower),
position=position_dodge(0.9),
data=means.sem)
+ theme(panel.background = element_rect(fill = “transparent”, color = “gray”),
legend.key = element_rect(fill = “transparent”, color = “transparent”),
axis.text = element_text(color = “black”))

就会在console处出现Error in inherits(x, “theme”) : argument “e2” is missing, with no default这样从错误，并且最后一行不会执行；

解决方案

想要解决这样的问题，一个比较简单的方案是分开放到不同的变量里面去
代码展示如下：
p<-means.barplot + geom_errorbar(aes(ymax=upper,
ymin=lower),
position=position_dodge(0.9),
data=means.sem)
+ theme(panel.background = element_rect(fill = “transparent”, color = “gray”),
legend.key = element_rect(fill = “transparent”, color = “transparent”),
axis.text = element_text(color = “black”))

p+ theme(panel.background = element_rect(fill = “transparent”, color = “gray”),
legend.key = element_rect(fill = “transparent”, color = “transparent”),
axis.text = element_text(color = “black”))
这样操作，图就会正常出来了