Lijngrafieken

Introductie tot datavisualisatie met ggplot2

Rick Scavetta

Founder, Scavetta Academy

Veelvoorkomende grafieken

Grafiektype	Mogelijke geoms
Spreidplots	points, jitter, abline, smooth, count
Staafdiagrammen	histogram, bar, col, errorbar
Lijngrafieken	line, path

Beaver

str(beaver)

'data.frame':    101 obs. of  3 variables:
 $ time  : POSIXct, format: "2000-01-01 09:30:00" "2000-01-01 09:40:00" "2000-01-01 09:50:00" ...
 $ temp  : num  36.6 36.7 36.9 37.1 37.2 ...
 $ active: Factor w/ 2 levels "0","1": 1 1 1 1 1 1 1 1 1 1 ...

Beaver

ggplot(beaver, aes(x = time, y = temp)) +
  geom_line()

Beaver

ggplot(beaver, aes(x = time, y = temp, 
                   color = factor(active))
                   ) +
  geom_line()

De fish catch-dataset

str(fish)

'data.frame':    427 obs. of  3 variables:
 $ Species: Factor w/ 7 levels "Pink","Chum",..: 1 2 3 4 5 6 7 1 2 3 ...
 $ Year   : int  1950 1950 1950 1950 1950 1950 1950 1951 1951 1951 ...
 $ Capture: int  100600 139300 64100 30500 0 23200 10800 259000 155900 51200 ...

Lijntype-esthetiek

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 linetype = Species)) + 
  geom_line()

Grootte-esthetiek

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 size = Species)) + 
  geom_line()

Kleur-esthetiek

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 color = Species)) + 
  geom_line()

Esthetiek voor categorische variabelen

Fill-esthetiek met geom_area()

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 fill = Species)) + 
  geom_area()

Gebruik van position = "fill"

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 fill = Species)) + 
  geom_area(position = "fill")

geom_ribbon()

ggplot(fish, aes(x = Year, 
                 y = Capture, 
                 fill = Species)) + 
  geom_ribbon(aes(ymax = Capture, 
                  ymin = 0), 
              alpha = 0.3)

Laten we oefenen!

Introductie tot datavisualisatie met ggplot2