记忆正态分布公式

R语言代码：

x <- seq(-2,2,0.1)
par(mfrow=c(2,3))

plot(c(-2,2), c(0,8), type='n')
lines(x, exp(x), col='red')

plot(c(-2,2), c(0,8), type='n')
lines(x, exp(abs(x)), col='red')

plot(c(-2,2), c(0,8), type='n')
lines(x, exp(x^2), col='red')

plot(c(-2,2), c(0,1), type='n')
lines(x, exp(-x^2), col='red')

plot(c(-2,2), c(0,1), type='n')
lines(x, exp(-x^2)/((pi)^0.5), col='red')

plot(c(-2,2), c(0,1), type='n')
lines(x, exp(-x^2/2)/((2*pi)^0.5), col='red')