How to use a variable to specify column name in ggplot

Question

I have a ggplot command

ggplot( rates.by.groups, aes(x=name, y=rate, colour=majr, group=majr) )

inside a function. But I would like to be a

Answer 1

Using aes_string does fix this problem, but does face an issue when adding error bars geom_errorbar. Below is a simple solution.

#Identify your variables using the names of your columns indie your dataset
 xaxis   <- "Independent"   
 yaxis   <- "Dependent"
 sd      <- "error"

#Specify error bar range (in 'a-b' not 'a'-'b')
 range   <- c(yaxis, sd)                                #using c(X, y) allows use of quotation marks inside formula
 yerrbar <- aes_string(ymin=paste(range, collapse='-'), 
                       ymax=paste(range, collapse='+'))


#Build the plot
  ggplot(data=Dataset, aes_string(x=xaxis, y=yaxis)) +
    geom_errorbar(mapping=yerrbar, width=15, colour="#73777a", size = 0.5) +
    geom_point   (shape=21)

Bonus, you can also add facets to your plot using these lines inside the ggplot:

facet_grid(formula(paste(Variable1, "~", Variable2)))

This script was modified from this original post: ggplot2 - Error bars using a custom function