# Gini index example (heterogeneity) with real-world data
source("analisidati.R")
ist <- c("scuola_secondaria","istituto.magistrale","istituto_professionale_commerciale","istituto_professionale_industriale","istituto_tecnico_altri",
"istituto_tecnico_commericiale","istituto_tecnico_industriale","classico","linguistico","scientifico","titolo_straniero")
abs.freq <- c(3,2,4,8,8,34,58,8,1,62,3)
x <- rep(ist,abs.freq)
gini(x)
entropia(x)
# plot
f <- table(x)/length(x)
par(mar=c(14.5,4.1,4.1,2.1))
plot(f,ylim=c(0,0.35),las=2,xlab="",ylab="",lwd=3,cex.axis=1,col="darkblue",type="h")
# another command to plot the data (frequency) 
label <- ist
par(mar=c(10.1,4.1,4.1,2.1))
mp <- barplot(f,las=2,ylim=c(0,0.35),col=rainbow(length(f)),axisnames = FALSE, axes= TRUE, space=1.5)    # bar midpoints
text(mp, par("usr")[3], labels = ist, srt = 45, adj = c(1.1,1.1), xpd = TRUE, cex=0.9)
text(y=f+0.02, x=mp, labels=as.character(round(f,3)),xpd=T);
#abline(h=seq(0,35,0.05),lty=1)
axis(side=1, at=mp, labels=FALSE)
text(c(0.225,2.5),"Immatricolati a.a. 2014/2015 SCUOLE SUPERIORI DI PROVENIENZA",adj=0)