sk.R

## Libraries we are going to need
library(tidyverse)
library(lubridate)

## Load in the data set
vdecls <- readxl::read_xlsx("stramkurs.xlsx", col_types=c("date"))
## Fixup the data set, since Excel is utter crap. There are some NA values, get
## rid of those
vdecls <- filter(vdecls, !is.na(vdecls))
## The name of the column is rather irritating, fixup
vdecls <- rename(vdecls, timestamp = ends_with("Kurs"))

## Kernel density
p <- ggplot(vdecls, aes(timestamp))
p + geom_density()

ggsave("density.png")

## Hours and weekdays are extracted so we can plot those
times <- vdecls %>%
    mutate(hour = hour(timestamp),
           wday = wday(timestamp, label=TRUE, abbr = TRUE))

p <- ggplot(times, aes(hour))
p + geom_histogram(stat="count")

ggsave("hourly.png")

p <- ggplot(times, aes(hour))
p + geom_histogram(stat="count") + facet_grid(rows = vars(wday))

ggsave("per_wday.png")