library(readxl)
datos=read_excel("D:/Descargas/DATABASES/practica componentes principales.xlsx")
datos1=datos[c(1:30),c(11:19)]
plot(datos1)
m=princomp(datos1,cor=TRUE)
m$scores
cor(datos1)
valvec=eigen(cor(datos1))
a=(m$scores[,1])/sqrt(valvec$values[1])
b=(m$scores[,2])/sqrt(valvec$values[2])
c=(m$scores[,3])/sqrt(valvec$values[3])

Arl=370
alfag=1/Arl
alfai=1-(1-alfag)^(1/3)
alfamedio=alfai/2

LCI=qnorm(alfamedio)
LCS=-LCI

datos2=datos[c(31:40),c(11:19)]
msc=m$scores
d=predict(m,newdata=datos2)
l=rbind(msc,d)

a=(l[,1])/sqrt(valvec$values[1])
b=(l[,2])/sqrt(valvec$values[2])
c=(l[,3])/sqrt(valvec$values[3])
plot(a,b)