Foro de discusión y soporte para usuarios de R

Hola amigos he hecho una pequeña simulación y quiere recomendaciones para mejorarla (en cuanto a la parte gráfica y forma):

p.Ftest = function( alpha,n ) {
x = seq(-4,4,length = 500)
yc = dnorm(x, 0, 1)
yn = dnorm(x, 0, 1)
#par(mfrow=c(1,1),mai=c(0.003,1,.4,.4))
plot(x, yc, type = "n",xlab="", ylab = "", ylim = c(0, max(yc,
yn)),axes=T)
xq = qnorm(1-alpha/2, 0, 1)
xp = qnorm(alpha/2, 0, 1)
polygon(c(xq, x[x >= xq]), c(0, yn[x > xq]), col = "orange",
border = NA)
polygon(c(xp, x[x <= xp]), c(0, yn[x < xp]), col = "orange",
border = NA)
curve(dnorm(x,0,1),col="gray1",lwd=3.5,add=T)

text(xq+0.3,dnorm(xq+0.2),bquote(paste("RC:",1 - alpha/2,"=",. (signif(alpha/2,3)))),pos=4,cex=0.85,col="gray1")
text(xp-0.3,dnorm(xp-0.2),bquote(paste("RC:",alpha/2,"=",.(signif(alpha/2,3)))),pos=2,cex=0.85,col="gray1")
# segments(0,0, 0,dnorm(0),col="gray", lty=3, lwd=3 )
text(-1.6,0.07,bquote(paste("Región de Aceptación",,"",)),pos=4,cex=1,col="blue")
text(-.8,0.03,bquote(paste("",1-alpha,"=",.(signif(1-alpha,3)))),pos=4,cex=1,col="blue")
title("Prueba de hipótesis para la media poblacional")
n=30
m<-seq(50,90,length=100)
a=mean(m)
b=mean(sample(m,n,replace=T))
et<-sd(m)/sqrt(n)
z=(b-a)/et
z
segments(z,0, z,dnorm(z),col="red", lty=3, lwd=3 )
text(z,dnorm(z),bquote(paste("",Zo,"=",. (signif(z,3)))),pos=4,cex=0.85)
}
p.Ftest ( 0.05,10)