plot an angle of 450 degrees and adding a circular arrow to it
Dear Jones: Could you please look to this R code. I am trying to graph both sin(x+pi/6) and sin(x) in the same plot to show the shift. I used abline to graph the sin(x), but it looked like same as the x-axis. x<-seq(-2.2*pi,2*pi,0.01) y<-sin(x+pi/6) #### To draw a box of the graph: #### ========================== plot(0:10, 0:10, type = "n", xaxt = "n", yaxs = "i", xaxs = "i", yaxt = "n", xlab = "", ylab = "") plot(x, y, type='l', lwd = 3, col="red", xaxt = "n", xlab="", ylab="") #### abline(v=c(-4*pi,-(7*pi)/2,-3*pi,-(5*pi)/2,-2*pi,-(3*pi)/2,-pi,-pi/2, 0,pi/2,pi,(3*pi)/2,2*pi,(5*pi)/2,3*pi,(7*pi)/2,4*pi),col="blue") abline(h=0, lwd=3) abline(v=0, lwd=3) x1<-seq(0,2*pi,0.01) y1<-sin(x1) abline(x1,y1, lwd = 3) thank you very much Steven
On Mon, Oct 20, 2014 at 1:08 PM, Steven Stoline <sstoline at gmail.com> wrote:
Many thanks it works Steven On Mon, Oct 20, 2014 at 11:17 AM, Albyn Jones <jones at reed.edu> wrote:
Here is a quickly written and barely tested function. You might want to
add a final position vector,
color, lwd, lty, etc. It assumes the angle is given in degrees, and
checks the sign of the angle to draw
in the correct direction.
albyn
=====================================================================
DrawAngle <- function(theta,r=1){
# assumes angles given in degrees, not radians
theta <- 2*pi*theta/360
plot(0,0, xlim=c(-2,2),ylim=c(-2,2))
abline(h=0)
abline(v=0)
sgn <- 1
if(theta <0) {
sgn <- -1
theta <- -theta
}
Theta <- sgn*seq(0,theta,.01)
if(theta > 2*pi) r <- seq(1,1.1,along.with=Theta)
x <- r*cos(Theta)
y <- r*sin(Theta)
lines(x,y)
n <- length(x)
arrows(x[n-1],y[n-1],x[n],y[n])
}
On Mon, Oct 20, 2014 at 1:47 AM, Steven Stoline <sstoline at gmail.com>
wrote:
Dear All:
I am wondering if someone can show me how to plot an angles around the
center of a unit circle with x-y vertices added to it.
Also how to add arrows showing the size and the direction of angle(s).
Examples: 135 degrees and 450 degrees angles.
with many thanks
Steven
--
Steven M. Stoline
1123 Forest Avenue
Portland, ME 04112
sstoline at gmail.com
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