data(iris)
iris.pca <- prcomp(iris[-5])
colores <- as.character(iris$Specie)
colores[colores=="setosa"] <- "red"
colores[colores=="virginica"] <- "black"
colores[colores=="versicolor"] <- "blue"
pairs(iris.pca$x,col=colores)

cat("\nValores propios\n")
##
## Valores propios
print(iris.pca$sdev)
## [1] 2.0562689 0.4926162 0.2796596 0.1543862
cat("\nValores propios en % \n")
##
## Valores propios en %
print(round(100*(iris.pca$sdev)/sum(iris.pca$sdev),1))
## [1] 68.9 16.5 9.4 5.2
cat("\nValores propios acumulados en % \n")
##
## Valores propios acumulados en %
print(cumsum(round(100*(iris.pca$sdev)/sum(iris.pca$sdev),1)))
## [1] 68.9 85.4 94.8 100.0
# Grafico PC1-2 variables
plot(iris.pca$rotation,pch='')
abline(h = 0, v = 0, col = "gray60")
text(iris.pca$rotation,labels=rownames(iris.pca$rotation))

# Grafico PC1-3 variables
plot(iris.pca$rotation[,1],iris.pca$rotation[,3],pch='.')
abline(h = 0, v = 0, col = "gray60")
text(iris.pca$rotation[,1],iris.pca$rotation[,3],labels=rownames(iris.pca$rotation))
