Reputation: 298
There is a slim gap in the graph after you run the code.
x = seq(0, 1, by=0.01)
y1=x
y2=x^2
plot(x, y1,type="l")
lines(x,y2,type="l",col="red")
xx1<-c(0,x[x<1 & x>0 ],1,x[x<1 & x>0 ],0)
yy1<-c(0,x[x<1 & x>0 ],1,(x[x<1 & x>0 ])^2,0)
polygon(xx1,yy1,col="yellow")
Please see the attachment,why is there a slim gap?how can i delete it,let it be filled by yellow colour ?
Upvotes: 3
Views: 78
Reputation: 32391
The cause of the problem is easier to see if you reduce the number of points:
x <- seq(0, 1, by=0.2)
plot( x, x, type="l" )
lines( x, x^2, col="red" )
xx1 <- c(0,x[x<1 & x>0 ],1,x[x<1 & x>0 ],0)
yy1 <- c(0,x[x<1 & x>0 ],1,x[x<1 & x>0 ]^2,0)
polygon(xx1, yy1, lwd=3, col="wheat")
points(xx1, yy1)
The points are correct, but the order is not.
For a convex polygon, xx1
should be first increasing, then decreasing.
plot( x, x, type="l" )
lines( x, x^2, col="red" )
xx1 <- c(x, rev(x))
yy1 <- c(x, rev(x)^2)
polygon(xx1, yy1, lwd=3, col="wheat")
Upvotes: 5