# RGB red-green-blue (rosso-verde-blu)
# I colori usabili sono 256^3 (i numeri da 0 a 255 sono scritti in base 16)
# Vedi qui per ulteriori informazioni.
# Aziona le righe seguenti:
plot(c(0,1),c(0,1),type="n",xlab="", ylab="",fg="white",xaxt="n",yaxt="n")
polygon( c(0,0,1/3,1/3),c(1,0,0,1),col="red" )
polygon( c(1/3,1/3,2/3,2/3),c(1,0,0,1),col="green" )
polygon( c(2/3,2/3,1,1),c(1,0,0,1),col="blue" )
# Ovvero:
plot(c(0,1),c(0,1),type="n",xlab="", ylab="",fg="white",xaxt="n",yaxt="n")
polygon( c(0,0,1/3,1/3),c(1,0,0,1),col="#FF0000" )
polygon( c(1/3,1/3,2/3,2/3),c(1,0,0,1),col="#00FF00" )
polygon( c(2/3,2/3,1,1),c(1,0,0,1),col="#0000FF" )
#
# Poi le seguenti, in cui i numeri sono trasformati nell'intervallo [0,1]
plot(c(0,1),c(0,1),type="n",xlab="", ylab="",fg="white",xaxt="n",yaxt="n")
polygon( c(0,0,1/3,1/3),c(1,0,0,1),col=rgb(1,0,0) )
polygon( c(1/3,1/3,2/3,2/3),c(1,0,0,1),col=rgb(0,1,0) )
polygon( c(2/3,2/3,1,1),c(1,0,0,1),col=rgb(0,0,1) )
#
# Esempio di colori diversi (grigio, giallo, viola):
plot(c(0,1),c(0,1),type="n",xlab="", ylab="",fg="white",xaxt="n",yaxt="n")
polygon( c(0,0,1/3,1/3),c(1,0,0,1),col=rgb(0.5,0.5,0.5) )
polygon( c(1/3,1/3,2/3,2/3),c(1,0,0,1),col=rgb(1,1,0) )
polygon( c(2/3,2/3,1,1),c(1,0,0,1),col=rgb(1,0,1) )
#
# Infine queste (ci vuole circa 1 minuto per tutte le uscite):
tic <- function(x) {sec <-proc.time()[3]; while(proc.time()[3] < sec+x) sec<-sec}
plot(c(0,1),c(0,1),type="n",xlab="", ylab="",fg="white",xaxt="n",yaxt="n")
g <- (0:5)/5; for(k in g)for(j in g)for(i in g){tic(0.2)
polygon( c(0,0,1,1),c(1,0,0,1),col=rgb(i,j,k) )
polygon( c(0.1,0.1,0.9,0.9),c(0.6,0.4,0.4,0.6),col=rgb(1,1,1) )
text(1/2,1/2,paste(i,"   ",j,"   ",k,sep=""))
if (floor(i)+floor(j)+floor(k)==i+j+k) tic(2) }