Base Graphics

Building Graphs

Incremental building of features into graphs.

Less is more

More visualization tips

References

1. Graphical parameters
2. Colors
3. Named colors - type colors()
4. Using color scales and plattes in R
5. ?plot
6. ?par
7. Specific options e.g. ?pch

Basic plots

In [1]:

head(mtcars)

Out[1]:

	mpg	cyl	disp	hp	drat	wt	qsec	vs	am	gear	carb
Mazda RX4	21	6	160	110	3.9	2.62	16.46	0	1	4	4
Mazda RX4 Wag	21	6	160	110	3.9	2.875	17.02	0	1	4	4
Datsun 710	22.8	4	108	93	3.85	2.32	18.61	1	1	4	1
Hornet 4 Drive	21.4	6	258	110	3.08	3.215	19.44	1	0	3	1
Hornet Sportabout	18.7	8	360	175	3.15	3.44	17.02	0	0	3	2
Valiant	18.1	6	225	105	2.76	3.46	20.22	1	0	3	1

In [8]:

plot(mtcars$wt, mtcars$mpg)

In [9]:

scatter.smooth(mtcars$wt, mtcars$mpg)

In [10]:

df <- mtcars[order(mtcars$wt),]
plot(df$wt, df$mpg, type="b")

In [11]:

hist(mtcars$mpg, breaks=10)

In [12]:

plot(density(mtcars$mpg), main="Density plot")

In [13]:

hist(mtcars$mpg, breaks=10, probability = TRUE, main="")
rug(mtcars$mpg)
x <- seq(min(mtcars$mpg), max(mtcars$mpg), length.out = 50)
lines(x, dnorm(x, mean=mean(x), sd=sd(x)), col="red", lwd=2)

In [14]:

pie(table(mtcars$carb))

In [15]:

barplot(table(mtcars$carb))

In [16]:

barplot(table(mtcars$carb), horiz=TRUE)

In [18]:

(tbl <- table(mtcars$carb, mtcars$am))
barplot(tbl, beside=TRUE, legend=rownames(tbl), col=heat.colors(mtcars$carb))

Out[18]:

0 1
  1 3 4
  2 6 4
  3 3 0
  4 7 3
  6 0 1
  8 0 1

In [19]:

boxplot(log1p(mtcars))

In [20]:

df <- mtcars[order(-mtcars$mpg),]
dotchart(df$mpg, labels=row.names(df))

In [21]:

dotchart(df$mpg, labels=row.names(df), groups=df$cyl, color=df$cyl, pch=19)

In [22]:

pairs(~mpg + drat + wt, data=mtcars)

Building plots

• Local customization of plots
• Glaobl customization of plots
• Adding more stuff to a plot
  • points
  • lines
  • text
  • mathematical expressions
• Combining plots
• Saving plots

Scatterplot

In [23]:

df <- mtcars[order(mtcars$wt),]
plot(df$wt, df$mpg)

Combining plots

In [24]:

par(mfrow=c(2,2))
plot(rnorm(10))
plot(rnorm(10))
plot(rnorm(10))
plot(rnorm(10))

In [25]:

(m <- matrix(c(1,1,2,3), 2, 2, byrow=TRUE))

Out[25]:

1	1
2	3

In [26]:

layout(m)
plot(rnorm(10))
plot(rnorm(10))
plot(rnorm(10))

In [27]:

layout(m, widths=c(1,2), heights=c(2,1))
plot(rnorm(10))
plot(rnorm(10))
plot(rnorm(10))

In [28]:

orig <- par(no.readonly=TRUE)
x <- rnorm(10)
y <- rnorm(10)
par(fig = c(0, 0.8, 0, 0.8))
plot(x, y)
par(fig = c(0, 0.8, 0.6, 1), new=TRUE)
plot(density(x), axes=FALSE, main="", xlab="")
par(fig = c(0.6, 1, 0, 0.8), new=TRUE)
boxplot(y, axes=FALSE)
par(orig)

In [ ]: