N <- 1000
x1 <- rnorm(N)
x2 <- 1 + x1 + rnorm(N)
quartz(height=4)
plot(0)
quartz(height=4)
plot(0,1)
quartz(height=4)
plot(x1)
# scatter plot x1 on the horizontal axis and x2 on the vertical axis
quartz(height=4)
plot(x1,x2)
# the same but using a formula (x2 as a function of x1)
quartz(height=4)
plot(x2 ~ x1)
# show all the available methods for plot (depending on the number of loaded packages).
methods(plot)
quartz(height=4)
plot(x1,x2, main = "Main title", sub = "sub title" , ylab = "Y axis", xlab = "X axis")
quartz(height=4)
plot(x1,x2 ,  ylab = "Y axis", xlab = "X axis")
title(main = "Main title", sub = "sub title" )
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1)
lines(x2, col = 2, lty = 2)
legend("bottomleft", legend = c("x1","x2"), col = 1:2, lty = 1:2)

quartz(height=4)
plot(x1,x2, main = "Main title", sub = "sub title" , ylab = "Y axis", xlab = "X axis")
quartz(height=4)
plot(x1,x2 ,  ylab = "Y axis", xlab = "X axis")
title(main = "Main title", sub = "sub title" )
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1)
lines(x2, col = 2, lty = 2)
legend("bottomleft", legend = c("x1","x2"), col = 1:2, lty = 1:2)
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1) ; mtext("some text", side = 1) # the bottom
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1) ; mtext("some text", side = 2) # the left
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1) ; mtext("some text", side = 3) # the top
quartz(height=4)
plot(x1, type = "l", col = 1, lty = 1) ; mtext("some text", side = 4) # the right margin

colors() # list the r colors

quartz(height=4)
plot(x1, type = "l", lty = "dotted")
abline(h= -3, lty = "dashed", col = "gray")
abline(v = 0, lty = "dashed", col = "gray")

curve(x^2, from = -1 , to = 1, main = "Quadratic function", ylab = "f(x)=x^2")
quartz(height=4)
plot(rnorm(100))
curve((x/100)^2, add = TRUE, col = "red")