How could I go on with the plot?

[Comede_way]

Hi,
Continuous variables are divided and frequencies counted in different interval, histograms are drawn, and probability density curves are fitted.
The horizontal coordinates are of the form of different intervals [a,b). Now it seems that the graph I made has problems with both the horizontal coordinates ( no scale lines)and vertical coordinates.
You could also use other data to show your opinion.
Thank you for your help in advance.

set.seed(123)
data <- rnorm(1000, mean = 50, sd = 10)
# 将x分为5个区间
cuts <- cut(data, breaks = c(0, 20, 40, 60, 80, 100), right = FALSE)

# 计算各个区间的频次
freqs <- table(cuts)

# 绘制直方图和概率密度曲线
barplot(freqs, names = c("[0,20)", "[20,40)", "[40,60)", "[60,80)", "[80,100)"))
lines(data, col = "red")

^{Created on 2023-04-09 with reprex v2.0.2}

[AlexisW]

Do you have a reason not to use the built-in R functions?

set.seed(123)
data <- rnorm(1000, mean = 50, sd = 10)


hist(data, freq = FALSE)
lines(density(data), col = 'red3')

[Comede_way]

@AlexisW Thank you for your help. I got the following picture using your code. While how could I change the labels of x-axis? As it shows, every bar in the plot has a corresponding interval [a, b), values of a and b are different between every bar. Is it possible to show them in x-axis? And not show the breaks value.

Maybe like this and then adds the density line.

[nirgrahamuk]

somewhat handcrafted, but its better than nothing ?

set.seed(123)
data <- rnorm(1000, mean = 50, sd = 10)


h1<-hist(data, freq = FALSE, xaxt = "n")

mybreaks <- h1$breaks
names(mybreaks) <- paste0("[",mybreaks,":",c(tail(mybreaks,-1),NA),"]")
mybreaks <- c(15,mybreaks)
axis(side=1,line=-.4, tck=0,at=mybreaks+2.5,labels = names(mybreaks),cex.axis=.5)
lines(density(data), col = 'red3')