# Che cosa appare? Carica tutto ed esegui. h <- function(x,y) x^3-y^2+1 x1 <- -3; x2 <- 5; y1 <- -4; y2 <- 4 x <- seq(x1,x2,len=1000); y <- seq(y1,y2,len=1000) z <- outer(x,y,h);contour(x,y,z,levels=0,drawlabels=FALSE, lwd=3,col='blue',asp=1) abline(h=axTicks(2), v=axTicks(1),lty=3,col='blue') abline(h=0, v=0,lty=2,col='blue') r <- function(x,y) (x-1)^2+(y-1.5)^2-5 z <- outer(x,y,r);contour(x,y,z,levels=0,drawlabels=FALSE, lwd=3,col='red',add=TRUE) k <- function(x,y) (x/y)^2-1 z <- outer(x,y,k);contour(x,y,z,levels=0,drawlabels=FALSE, lwd=3,col='brown',add=TRUE) t <- function(x,y) x*y-x^2+y^2/3+1-x/2 z <- outer(x,y,t);contour(x,y,z,levels=0,drawlabels=FALSE, lwd=3,col='green',add=TRUE) # # ALTERNATIVA: # source("http://macosa.dima.unige.it/r.R") BF=4; HF=4 PLANE(-3,5, -4,4) h <- function(x,y) x^3-y^2+1; CURVE(h,"blue") r <- function(x,y) (x-1)^2+(y-1.5)^2-5; CURVE(r,"red") k <- function(x,y) (x/y)^2-1; CURVE(k,"brown") t <- function(x,y) x*y-x^2+y^2/3+1-x/2; CURVE(t,"green") #