## Normal Mixture

Let be the normal density function with mean and standard deviation (SD) . Given parameters , , , , and , the ``normal mixture'' density is defined as

> source("nm.r") > x = seq(0,1,by=0.01) > plot(x, nm(x), type="l", xlab="x", ylab="PDF", main="Normal mixture")

Programming note.
The function ```nm()`'' is defined
in the source file
nm.r
and written in the form

nm = function(x, p=c(0.3, 0.2, 0.8, 0.1, 0.4)){ p[5] * dnorm(x, p[1], p[2]) + (1-p[5]) * dnorm(x, p[3], p[4]) }It is executed by

> y = mn(0.2)The argument ``

`p`'' is optional, and given ``

`c(0.3, 0.2, 0.8, 0.1, 0.4)`when omitted. The function returns the value

p[5] * dnorm(x, p[1], p[2]) + (1-p[5]) * dnorm(x, p[3], p[4])in which

`dnorm()`returns the normal density value.

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