Graphics Reference
In-Depth Information
Figure
.
.
A doubledecker plot of Toronto arrest data. Source: Fox (
)
own show that diesel cars have generally lower fuel consumption (in Europe con-
sumption is measured in litres/
km). he barchart on the let shows that little at-
tention should be paid to the (Natural) Gas and Hybrid groups as few of these cars
were measured. Should these two groups have been let out or perhaps be replaced
bydotplots? Small groupsarealways aproblem.It shouldalso benoted that the units
for natural gas cars are different (kg/
km) from the others.
Small multiples can work well, but careful captioning is necessary to ensure that
it is clear which smaller plot is which, and common scaling is obviously essential.
Figure
.
is a trellis display of emissions data for the
petrol or diesel cars. hey
have been grouped byengine type(rows)and engine size (columns). An equal count
grouping has been used for engine size, which is why the shaded parts of the cc bars
have different lengths. Engine size seems to make little difference as the plots in each
roware similar toone another. hetypeof engine makes moredifference,with diesel
Figure
.
.
Boxplots of fuel consumption by engine type data from Germany. he barchart shows the
relative numbers of cars involved. he total number was
. Source: http://www.adac.de, March
