Looping over columns of data frame to create plots with ggplot2 - r

Question

I am trying to overcome this. Can't get any further.
I have a dataframe with factor and numeric variables. Herewith displayed are the first few rows and columns.
# A tibble: 6 x 5
cluster SEV_D SEV_M OBS PAN
<int> <dbl> <dbl> <fct> <fct>
1 1 5 1 0 1
2 2 6 1 0 0
3 1 5 1 0 1
4 2 4 2 0 0
5 1 4 1 1 1
6 1 4 2 1 0
cluster=as.factor(c(1,2,1,2,1,1))
SEV_D=as.numeric(c(5,6,5,4,4,4))
SEV_M=as.numeric(c(1,1,1,2,1,2))
OBS=as.factor(c(0,0,0,0,1,1))
PAN=as.factor(c(1,0,1,0,1,0))
data<-data.frame(cluster,SEV_D,SEV_M,OBS,PAN)
I split the dataframe like this, in numeric and factor variables, keeping 'cluster' in both subsets since I need it for grouping.
data_fact <- data[, sapply(data, class) == 'factor']
data_cont <- data[, sapply(data, class) == 'numeric' | names(data)
== "cluster"]
The two following snippets of code would produce the plots I want.
data_fact %>% group_by(cluster,OBS)%>%summarise(total.count=n()) %>%
ggplot(., aes(x=cluster, y=total.count, fill=OBS)) +
geom_bar(position = 'dodge', stat='identity') +
geom_text(aes(label=total.count),
position=position_dodge(width=0.9), vjust=-0.2)
data_cont %>% group_by(cluster) %>% dplyr::summarise(mean =
mean(SEV_D), sd = sd(SEV_D)) %>%
ggplot(.,aes(x=cluster,y=mean))+geom_bar(position=position_dodge(),
stat="identity",colour="black",size=.3)+geom_errorbar(aes(ymin=mean-
sd, ymax=mean+sd),size=.3,width=.4,position=position_dodge(.4)) +
ggtitle("SEV_D")
My goal is to create as many graphs as variables in the data frame, looping over columns and to store such graphs in one single sheet.
My attempt was
col<-names(data_fact)[!names(data_fact)%in%"cluster"]
for(i in col) {
data_fact %>% group_by(cluster,i)%>%summarise(total.count=n()) %>%
ggplot(., aes(x=cluster, y=total.count, fill=i)) + geom_bar(position
= 'dodge', stat='identity') + geom_text(aes(label=total.count),
position=position_dodge(width=0.9), vjust=-0.2)
}
But it throws this error:
Error in grouped_df_impl(data, unname(vars), drop) :
Column i is unknown
On top of that, that code would not display all graphs in one sheet I am afraid. Any help would be much appreciated!!!

Answer 1

The link above is a good reference. Or see Rstudio's tidyeval cheatsheet: https://github.com/rstudio/cheatsheets/raw/master/tidyeval.pdf
To evaluate i in the ggplot statement, you need to unquote the string with the !!ensym( ) function construct. Also, you will need to use the print statement to print the plots within the loop.
library(ggplot2)
col<-names(data_fact)[!names(data_fact)%in%"cluster"]
for(i in col) {
print(i)
g<-data_fact %>% group_by(cluster, !!ensym(i)) %>% summarise(total.count=n()) %>%
ggplot(., aes(x=cluster, y=total.count, fill=!!ensym(i))) +
geom_bar(position = 'dodge', stat='identity') +
geom_text(aes(label=total.count), position = position_dodge(width=0.9), vjust=-0.2) +
labs(title=i)
print(g)
}