A line graph is very similar to a scatter plot, yet, instead of drawing dots in connects them with a smoot line.
In R, this can be achieved, for example, with plot and the argument type="l".
The following is mostly a copy paste of this example, yet with using type="l" instead of type="p":
x11()
x <- seq(-6, 10, by=0.25) # c(-6:10)
y <- x*x*x/8 - 9*x -15
x11()
plot(x, y,
type="l" , # Type = "l" --> line graph
main="Line Graph", # Title
xlim=c(-8,12) , # range for x
ylim=c(-45,15) , # range for y
col ="blue" , # color
)
# wait for mouse click or enter pressed
z <- locator(1)
