Curve, Constants, lockBinding,locator()

# Show how to choose floating point length, create the constant e  and bind it to the global environment
# Use curve() function to create a sine wave plot with constants pi and e
# use locator() to select arbitrary points which can be plotted again

options(digits=22)
e <- exp(1)
lockBinding("e", globalenv())
e
# [1] 2.718281828459

curve(sin, e^pi, -pi^-e)  # produces plot
z <- as.matrix(locator()) # select points on plot then right click and choose 'stop'

# locator() creates x,y matrix

z                       x                         y
# 1  1.906552221196785357193 -0.4129490482535249085139
# 2  4.856457177229445143496 -0.3680698252087759581030
# 3  7.107700433149108043551 -0.3643298899550468927799
...

plot(z)