how to put standard error bars on my ggplot2 2-factor bar graphic?

I've been trying for a while to change my current standard deviation bars into standard error bars in my bar plot.

This is the plot with mean+sd:

EGG <- data.frame(type = c("this", "this", "that", "that"),
                  chemcon = c(10,11,12,13),
                  day = c("Monday", "Tuesday", "Monday", "Tuesday"))

EGG
#>    type chemcon     day
#> 1  this      10  Monday
#> 2  this      11 Tuesday
#> 3  that      12  Monday
#> 4  that      13 Tuesday

require(ggplot2)
aa <- aggregate(chemcon ~ day + type, data=EGG, FUN=mean)
bb <- aggregate(chemcon ~ day + type, data=EGG, FUN=sd)
cc <- merge(aa, bb, by=c("day", "type"))
colnames(cc)[3:4] <- c("mean", "sd")

ggplot(cc, aes(x = type, y = mean, fill = day))+
  geom_bar(stat="identity", position= "dodge") + #nb you can just use 'dodge' in barplots
  scale_fill_brewer(palette="Paired")+
  theme_minimal() +
  labs(x="", y="chemcon") +
  theme(panel.background = element_blank(),
        axis.line = element_line(colour = "black"),
        panel.grid=element_blank()) +
  geom_errorbar(aes(ymin = mean-sd,
                    ymax = mean+sd), 
                position = "dodge")

I tried to replace the function (FUN) of aggregate of "sd" with "se", no luck, then I tried to create "se" also with no luck:

se = sd(Egg$chemcon) / sqrt(length(Egg$chemcon))

The issue is because I must keep the "aggregate" function due to it working the best when trying to represent a two-factor bar plot, but haven't I seen anyone use it quite like this anywhere else with standard error. Can someone please help me understand what I'm missing?

Solution

Try std.error() from plotrix package as shown below

library(plotrix)
library(ggplot2)
EGG <- data.frame(type = rep(c("this", "this", "that", "that"),2),
                  chemcon = c(10,11,12,13,14,15,16,17),
                  day = rep(c("Monday", "Tuesday"),4))

EGG

aa <- aggregate(chemcon ~ day + type, data=EGG, FUN=mean)
bb <- aggregate(chemcon ~ day + type, data=EGG, FUN=sd)
ee <- aggregate(chemcon ~ day + type, data=EGG, FUN=std.error)  ##  from library(plotrix)
#ee <- aggregate(chemcon ~ day + type, data=EGG, FUN=sd(x)/sqrt(sum(!is.na(x))) )
# cc <- aggregate(chemcon ~ day + type, data=EGG, FUN = function(x) c(mean = mean(x), sd = sd(x), se = (sd(x)/sqrt(sum(!is.na(x)))) ))
cc <- merge(aa, ee, by=c("day", "type"))
colnames(cc)[3:4] <- c("mean", "se")


ggplot(cc, aes(x = type, y = mean, fill = day))+
  geom_bar(stat="identity", position= "dodge") + #nb you can just use 'dodge' in barplots
  scale_fill_brewer(palette="Paired")+
  theme_minimal() +
  labs(x="", y="chemcon") +
  theme(panel.background = element_blank(),
        axis.line = element_line(colour = "black"),
        panel.grid=element_blank()) +
  geom_errorbar(aes(ymin = mean-se,
                    ymax = mean+se), 
                position = "dodge")