Low-level plotting commands

Question 1

points(x, y)

Answer 1

adds points (the option type= can be used)

Question 2

lines(x, y)

Answer 2

id. but with lines

Question 3

text(x, y, labels, …)

Answer 3

adds text given by labels at coordi-

nates (x,y); a typical use is: plot(x, y, type=”n”); text(x, y, names)

Question 4

mtext(text, side=3, line=0, …)

Answer 4

adds text given by text in the margin specified by side (see axis() below); line specifies the line from the plotting area

Question 5

segments(x0, y0, x1, y1)

Answer 5

draws lines from points (x0,y0) to points (x1,y1)

Question 6

arrows(x0, y0, x1, y1, angle= 30, code=2)

Answer 6

id. with arrows at points (x0,y0) if code=2, at points (x1,y1) if code=1, or both if code=3; angle controls the angle from the shaft of the arrow to the edge of the arrow head

Question 7

abline(a,b)

Answer 7

draws a line of slope b and intercept a

Question 8

abline(h=y)

Answer 8

draws a horizontal line at ordinate y

Question 9

abline(v=x)

Answer 9

draws a vertical line at abcissa x

Question 10

abline(lm.obj)

Answer 10

draws the regression line given by lm.obj

Question 11

rect(x1, y1, x2, y2)

Answer 11

draws a rectangle which left, right, bottom, and

top limits are x1, x2, y1, and y2, respectively

Question 12

polygon(x, y)

Answer 12

draws a polygon linking the points with coordinates given

by x and y

Question 13

legend(x, y, legend)

Answer 13

adds the legend at the point (x,y) with the sym-

bols given by legend

Question 14

title()

Answer 14

adds a title and optionally a sub-title

Question 15

axis(side, vect)

Answer 15

adds an axis at the bottom (side=1), on the left (2),
at the top (3), or on the right (4); vect (optional) gives the abcissa (or
ordinates) where tick-marks are drawn

Question 16

rug(x)

Answer 16

draws the data x on the x-axis as small vertical lines

Question 17

locator(n, type=”n”, …)

Answer 17

returns the coordinates (x,y) after the
user has clicked n times on the plot with the mouse; also draws sym- bols (type=”p”) or lines (type=”l”) with respect to optional graphic parameters (…); by default nothing is drawn (type=”n”)