# Added means & sds
means <- c(0, 0, 0, -2)
sds <- c(sqrt(0.2), 1.0, sqrt(5.0), sqrt(0.5))
y1 <- dnorm(x, mean = means[1], sd = sds[1])
plot(x, y1, type = "l", col = "red", lwd = 2, ylab = "", xlab = "",
main = "Normal Distributions", ylim = c(0, 1), yaxt = "n", xaxt = "n")
# Added axis
axis(2, at = seq(0, 1, by = 0.2), las = 2)
axis(1, at = seq(-5, 5, by = 1))
# Added grid lines
abline(h = seq(0, 1, by = 0.2), col = "gray", lty = "dotted")
abline(v = seq(-5, 5, by = 1), col = "gray", lty = "dotted")
y2 <- dnorm(x, mean = means[2], sd = sds[2])
lines(x, y2, type = "l", col = "green", lwd = 2)
y3 <- dnorm(x, mean = means[3], sd = sds[3])
lines(x, y3, type = "l", col = "blue", lwd = 2)
y4 <- dnorm(x, mean = means[4], sd = sds[4])
lines(x, y4, type = "l", col = "purple", lwd = 2)
# Added explanations (right)
legend("topright", legend = c(expression(mu == 0 ~ ", " ~ sigma^2 == 0.2),
expression(mu == 0 ~ ", " ~ sigma^2 == 1.0),
expression(mu == 0 ~ ", " ~ sigma^2 == 5.0),
expression(mu == -2 ~ ", " ~ sigma^2 == 0.5)),
col = c("red", "green", "blue", "purple"), lty = 1, cex = 0.8)
# Added explanations (left)
legend("topleft", legend = c(expression(mu == "mean"),
expression(sigma == "standard deviation"),
expression(sigma^2 == "variance")),
cex = 0.8)
