Hi. I need to draw a circle whit center (a,b) and radio r. So I use the R code below a<-1.975 # valore x del centro b<-1.215 # valores y del centro r<-1.46 # radio x1<-seq(a-r,a+r,by=0.01); #los valores de x yp<-sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra??z positiva yn<-(-1)*sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra??z negativa x<-c(x1,x1); y<-c(yp,yn); plot(x,y,type="l",ylab="",xlab="",xlim=range(x),ylim=range(y)); My circle have two problems. First. I don't want the horizontal line and I don't know how avoid it. Second. It is shaped like ellipse. I need adjust the x and y scales, but I don't know how. Can you help me??? there is another way to draw a circle whit R ?
See ?symbols. For example: > a <- 1.975 # valore x del centro > b <- 1.215 # valores y del centro > r <- 1.460 # radio > plot(0,0, type = "n", ylim=c(b - r, b + r), xlim=c(a - r, a + r)) > symbols(x = a, y = b, circles = r) Mario Morales wrote:> Hi. > > I need to draw a circle whit center (a,b) and radio r. So I use the > R code below > > a<-1.975 # valore x del centro > b<-1.215 # valores y del centro > r<-1.46 # radio > x1<-seq(a-r,a+r,by=0.01); #los valores de x > yp<-sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra??z positiva > yn<-(-1)*sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra??z negativa > x<-c(x1,x1); y<-c(yp,yn); > > plot(x,y,type="l",ylab="",xlab="",xlim=range(x),ylim=range(y)); > > > My circle have two problems. > > First. I don't want the horizontal line and I don't know how avoid > it. > > Second. It is shaped like ellipse. I need adjust the x and y scales, > but I don't know how. > > Can you help me??? > > there is another way to draw a circle whit R ? > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > >-- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 452-1424 (M, W, F) fax: (917) 438-0894
Mario Morales wrote:> I need to draw a circleI would do it with complex numbers and polar coordinates: Circle = function (t,a) {a*cos(t)+1i*a*sin(t)} interval=c(-8,8) plot(interval,interval,type="n",xlab="",ylab="", asp=1,axes=F) t=seq(0,2*pi,by=0.01) center=2+3i; radius=5 lines(center+Circle(t,radius)) locator(1) dev.off() Josef Eschgf??ller -- Josef Eschgf??ller Dipartimento Matematico Universita' di Ferrara http://felix.unife.it
Try
a<-1.975 # valore x del centro
b<-1.215 # valores y del centro
r<-1.46 # radio
symbols(a,b,circle=r,inches=F)
Hope it works
PS:
Espero que te funcione.
Saludos desde Medell{in, Colombia.
On Thu, 19 May 2005 05:14:44 -0500, Mario Morales
<malfonso at telecom.com.co> wrote:
> Hi.
>
> I need to draw a circle whit center (a,b) and radio r. So I use the
> R code below
>
> a<-1.975 # valore x del centro
> b<-1.215 # valores y del centro
> r<-1.46 # radio
> x1<-seq(a-r,a+r,by=0.01); #los valores de x
> yp<-sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra伱伃z positiva
> yn<-(-1)*sqrt(r^2-(x1-a)^2)+b; # los valores y a partir de la ra伱伃z
> negativa
> x<-c(x1,x1); y<-c(yp,yn);
>
>
plot(x,y,type="l",ylab="",xlab="",xlim=range(x),ylim=range(y));
>
>
> My circle have two problems.
>
> First. I don't want the horizontal line and I don't know how avoid
> it.
>
> Second. It is shaped like ellipse. I need adjust the x and y scales,
> but I don't know how.
>
> Can you help me???
>
> there is another way to draw a circle whit R ?
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
--
Kenneth Roy Cabrera Torres
Uninversidad Nacional de Colombia
Sede Medellin
Tel 430 9351
Cel 315 504 9339