#activate the package
library(ggplot2)

#load the dataframe
time <- rep(0:23,2)
location <- c(rep("Østerbø", 24), rep("Lygra",24))
solarrad <- c(0,0,0,0,0,0,14,53,183,308,323,558,509,609,693,685,702,651,514,393,253,104,33,1,	
              0,0,0,0,0,12,43,82,260,396,506,624,727,780,519,544,284,229,557,425,148,38,23,0)
my.dataframe <- data.frame(time, location, solarrad)

#simple line plot with ggplot
ggplot(my.dataframe, aes(time, solarrad, color=location)) +
  geom_line()

#changing line thickness
ggplot(my.dataframe, aes(time, solarrad, color=location)) +
  geom_line(size=1.25)

#changing linetype
ggplot(my.dataframe, aes(time, solarrad, linetype=location)) +
  geom_line(size=1.25)

#combining linetype and color
ggplot(my.dataframe, aes(time, solarrad, color=location, linetype=location)) +
  geom_line(size=1.25)

#adding shapes
ggplot(my.dataframe, aes(time, solarrad, color=location, linetype=location)) +
  geom_line(size=1.25) +
  geom_point(size=2.5)

#adding different shapes
ggplot(my.dataframe, aes(time, solarrad, color=location, linetype=location, shape=location)) +
  geom_line(size=1.25) +
  geom_point(size=2.5)

#using viridis
ggplot(my.dataframe, aes(time, solarrad, color=location, linetype=location, shape=location)) +
  geom_line(size=1.25) +
  geom_point(size=2.5) +
  scale_color_viridis_d()