Graphing a histogram overlaid with a fitted 2 parameter Weibull function - r

Question

I would like to plot both a histogram to a fitted Weibull function on the same graph. The code to plot the histogram is:
hist(data$grddia2, prob=TRUE,breaks=5)
The code for the fitted Weibull function is:(Need the MASS package)
fitdistr(data$grddia2,densfun=dweibull,start=list(scale=1,shape=2))
How do I plot both together on the same graph. I've attached the data set.
Also, bonus to anyone who can provide code that can achieve the same thing, but create a graph for each column of data. Many columns within a data set. Would be nice to have all graphs on the same page.
https://www.dropbox.com/s/ra9c2kkk49vyyyc/Diameter%20Distribution.csv?dl=0

Answer 1

Here is the code
library("ggplot2")
library("dplyr")
library("tidyr")
library("MASS")
# Import dataset and filter the column "treeno"
# Use namespace dplyr:: explicitly because of conflict with MASS:: for function "select"
data <- read.csv("Diameter Distribution.csv") %>%
dplyr::select(-treeno)
# Function to provide the Weibull distribution for each column
# The distribution is calculated based on the estimated scale and shape parameters of the input
fitweibull <- function(column) {
x <- seq(0,7,by=0.01)
fitparam <- column %>%
unlist %>%
fitdistr(densfun=dweibull,start=list(scale=1,shape=2))
return(dweibull(x, scale=fitparam$estimate[1], shape=fitparam$estimate[2]))
}
# Apply function for each column then consolidate all in a data.frame
fitdata <-data %>%
apply(2, as.list) %>%
lapply(FUN = fitweibull) %>%
data.frame()
# Display graphs
multiplyingFactor<-10
ggplot() +
geom_histogram(data=gather(data), aes(x=value, group=key, fill=key), alpha=0.2) +
geom_line(data=gather(fitdata), aes(x=rep(seq(0,7,by=0.01),ncol(fitdata)), y=multiplyingFactor*value, group=key, color=key))
And the output figure
Variant: thanks to the wonderful ggplot2 package you can also have the graphs apart just by adding this final line of code
+ facet_wrap(~ key) + theme(legend.position = "none")
Which gives you this other figure: