Graphics Reference
In-Depth Information
# Keep 1 out of every 5 values in x and y, and 1 in 2 values in z
keepx
<-
every_n(unique(isabel$x), by
=
5
)
keepy
<-
every_n(unique(isabel$y), by
=
5
)
keepz
<-
every_n(unique(isabel$z), by
=
2
)
isub
<-
subset(isabel, x
%in%
keepx
&
y
%in%
keepy
&
z
%in%
keepz)
ggplot(isub, aes(x
=
x, y
=
y))
+
geom_segment(aes(xend
=
x
+
vx
/
50
, yend
=
y
+
vy
/
50
, colour
=
speed),
arrow
=
arrow(length
=
unit(
0.1
,
"cm"
)), size
=
0.5
)
+
scale_colour_continuous(low
=
"grey80"
, high
=
"darkred"
)
+
facet_wrap( ~ z)
Figure 13-24. Vector field of wind speeds faceted on z
See Also
If you want to use a different color palette, see
Using a Manually Deined Palette for a Continu-
