RG#21: Plotting curves (any formula, normal density )

#Example:
 curve(x^2, col = "red")

curve(x^3-x+1.5,from=-10,to=10,lty=2, col = "blue")

 # normal curve

x=seq(-50,150,length=1000)

set.seed(1234)
y=dnorm(x,mean=50,sd=30)
plot(x,y,type="l",lwd=2,col="red")

# add one or more curves

curve(x^2-1, col = "green2")

curve(x^2-5*x, -2.5, 2.5, add = TRUE, col = "red")

 

# add curves to scatter plot

# xyscatter plot

set.seed(1234)

x = c(0.1, 0.2, 0.3, 0.4, 0.5)

y = (-0.5*log (1-(2*x)) + rnorm(length (x), 0.2, 0.1))

plot(x,y, col = "red",  pch = 18)

 

curve(-0.5*log (1-(2*x)),from=0,to=0.5, lty=2,   col = "blue", add = TRUE)