#Thanks to Mark and Cathy

pdf("powerhw.pdf")
par(mfrow=c(1,1))
par(pty="s")

theta<-seq(-2,6,by=.001)

plot(theta,1-pnorm(1.645-theta*sqrt(1)),lty=1,lwd=2)

lines(theta,1-pnorm(1.645-theta*sqrt(4)),lty=2,lwd=2)

lines(theta,1-pnorm(1.645-theta*sqrt(16)),lty=3,lwd=2)

lines(theta,1-pnorm(1.645-theta*sqrt(64)),lty=4,lwd=2)

lines(theta,1-pnorm(1.645-theta*sqrt(100)),lty=5,lwd=2)

leg.txt<-c(" 670 HW-7 Power Function for sigma=1")

legend(x="bottomright", y = NULL , legend=leg.txt)

dev.off()