ggplot dot covering error bar - r

Question

I have a huge file and I don't really know what small test dataset I can give here to produce the same problem in the plot, so I will not give any test dataset, I will only attach the plot image here to show the problem.
My code:
ggplot(tgc, aes(x=Week, y=MuFreq)) +
theme_gray(base_size=18) +
theme(plot.title=element_text(hjust=.5),
axis.title.x = element_text(face="bold"),
axis.title.y = element_text(face="bold")) +
geom_errorbar(aes(ymin=MuFreq-(1.96*se), ymax=MuFreq+(1.96*se)), width=3) +
geom_line() +
geom_point(aes(size= N), color="blue")+
scale_x_continuous(breaks=c(68,98,188), labels=c("Wk68", "Wk98", "Wk188")) +
scale_y_continuous(limits=c(0,0.15)) +
scale_size( breaks = unique(tgc$N))
So the problem is that I'm sizing the dots based on the sample size for each week, the middle dot actually has error bars associated with it but it's covering the error bar. I tried to use horizontal error bar but it didn't work because my x-axis is customized to be non-numerical.
What can I do to show the error bar that's being covered?
Also is there any way to make the background vertical grid lines spaced evenly?

Answer 1

The Q asks to improve two things in the ggplot2 chart:
Show error bars that are being covered
Make the background vertical grid lines spaced evenly
Data
As the OP didn't supply any data, we need a dummy data set. This is easily done by reading values from the plot:
tgc <- data.frame(Week = c(68, 98, 188),
MuFreq = c(0.08, 0.09, 0.091),
se = c(0.003, 0.001, 0.019)/1.96,
N = c(91, 835, 7))
This reproduces the original plot quite nicely:
Variant 1
This one is picking up Nick Criswell's comments:
Change order in which layers are plotted, so that error bars are plotted on top
Change colour and alpha
plus
Remove all vertical grid lines except those which are explicetly specified as breaks. The distances of major grid lines are still uneven but reflect the difference in time
With this code
library(ggplot2)
ggplot(tgc, aes(x = Week, y = MuFreq)) +
theme_gray(base_size = 18) +
theme(plot.title = element_text(hjust = .5),
axis.title = element_text(face = "bold")) +
geom_line() +
geom_point(aes(size = N), color = "dodgerblue1", alpha = 0.5) +
geom_errorbar(aes(ymin = MuFreq - (1.96 * se),
ymax = MuFreq + (1.96 * se)), width = 3) +
scale_x_continuous(
breaks = c(68, 98, 188),
labels = c("Wk68", "Wk98", "Wk188"),
minor_breaks = NULL
) +
scale_y_continuous(limits = c(0, 0.15)) +
scale_size(breaks = unique(tgc$N))
we do get:
Variant 2
To get evenly spaced data points on the x-axis we can turn weeks into factor. This requires to tell ggplot2 that the data belong to one group in order to have lines plotted and to add a custom x-axis label.
In addition, theme_bw is used instead of theme_gray:
library(ggplot2)
ggplot(tgc, aes(x = factor(Week, labels = c("Wk68", "Wk98", "Wk188")),
y = MuFreq, group = 1)) +
theme_bw(base_size = 18) +
theme(plot.title = element_text(hjust = .5),
axis.title = element_text(face = "bold")) +
geom_line() +
geom_point(aes(size = N), color = "dodgerblue1", alpha = 0.5) +
geom_errorbar(aes(ymin = MuFreq - (1.96 * se),
ymax = MuFreq + (1.96 * se)), width = 0.05 ) +
scale_y_continuous(limits = c(0, 0.15)) +
scale_size(breaks = unique(tgc$N)) +
xlab("Week")