# EXAMPLE 7: Introduction to Statistics for Astrophysicists # SS 2012 # JOCHEN WELLER # LOG-NORMAL PROBABILITY x=seq(0,4,by=0.1) mu=0.0 sigma=1.0 norm=1.0/sqrt(2.0*pi)/sigma plot(x,norm*exp(-(log(x)-mu)^2/sigma^2)/x,type='l',xlim=c(0,4),ylim=c(0,1),xlab='x',ylab="f(x;mu,sigma)",lwd=2) mu=0 sigma=1.5 norm=1.0/sqrt(2.0*pi)/sigma lines(x,norm*exp(-(log(x)-mu)^2/sigma^2)/x,lwd=2,lty=2) mu=0 sigma=0.5 norm=1.0/sqrt(2.0*pi)/sigma lines(x,norm*exp(-(log(x)-mu)^2/sigma^2)/x,lwd=2,lty=3) mu=1 sigma=1.0 norm=1.0/sqrt(2.0*pi)/sigma lines(x,norm*exp(-(log(x)-mu)^2/sigma^2)/x,lwd=2,lty=4) legend("topright",legend=c("mu=0,sigma=1","mu=0,sigma=1.5","mu=0,sigma=0.5","mu=1,sigma=1"),lty=c(1,2,3,4),lwd=c(2,2,2,2),col=c("black","black","black","black"))