ellipse

Are there any predefined methods in c# which allow for collision detection? I am new to c# and am trying to get collision detection of two ellipses are there any predefined ways collision detection can be implemented? I already have code which draws the ellipses, what would be a good way to start the collision detection? private void timer1_Tick(object sender, EventArgs e) { //Remove the previous ellipse from the paint canvas. canvas1.Children.Remove(ellipse); if (--loopCounter == 0) timer.Stop(); //Add the ellipse to the canvas ellipse = CreateAnEllipse(20, 20); canvas1.Children.Add(ellipse);

I have this set of x and y coordinates: x<-c(1.798805,2.402390,2.000000,3.000000,1.000000) y<-c(0.3130147,0.4739707,0.2000000,0.8000000,0.1000000) as.matrix(cbind(x,y))->d and I want to calculate the ellipsoid that contains this set of points, I use the function ellipsoidhull() in the package "cluster", and I get: > ellipsoidhull(d) 'ellipsoid' in 2 dimensions:` center = ( 2.00108 0.36696 ); squared ave.radius d^2 = 2` and shape matrix = x 0.66590 0.233106 y 0.23311 0.095482 hence, area = 0.60406 However it's not obvious to me how I can get from these results, the lengths of the semi-major

I've been trying to solve a problem. I'm surprised I haven't been able to find anything really useful on the net. I know that from the eigenvalues of the covariance matrix of the ellipse, the major and the minor axis of the ellipse can be computed. As the following: a1 = 2*sqrt(e1) a2 = 2*sqrt(e2) where a1 and a2 are the major and minor axis, e1 and e2 are the eigenvalues of covariance matrix. My question is: given an edge points (xi,yi) of the image ellipse, how it possible to find the 2×2 covariance matrix of that ellipse? Just by pure reverse engineering (I'm not familiar anymore with this

I'm trying to count given data points inside each ring of ellipse: The problem is that I have a function to check that: so for each ellipse, to make sure whether a point is in it, three inputs have to be calculated: def get_focal_point(r1,r2,center_x): # f = square root of r1-squared - r2-squared focal_dist = sqrt((r1**2) - (r2**2)) f1_x = center_x - focal_dist f2_x = center_x + focal_dist return f1_x, f2_x def get_distance(f1,f2,center_y,t_x,t_y): d1 = sqrt(((f1-t_x)**2) + ((center_y - t_y)**2)) d2 = sqrt(((f2-t_x)**2) + ((center_y - t_y)**2)) return d1,d2 def in_ellipse(major_ax,d1,d2): if

I seem to be having some trouble getting this code to work: import Image, ImageDraw im = Image.open("1.jpg") draw = ImageDraw.Draw(im) draw.ellipse((60, 60, 40, 40), fill=128) del draw im.save('output.png') im.show() This should draw an ellipse at (60,60) which is 40 by 40 pixels. The image returns nothing. This code works fine however: draw.ellipse ((0,0,40,40), fill=128) It just seems that when i change the first 2 co-ords (for where the ellipse should be placed) it won't work if they are larger than the size of the ellipse to be drawn. For example: draw.ellipse ((5,5,15,15), fill=128) Works

Sorry if this is a stupid question, but is there an easy way to plot an ellipse with matplotlib.pyplot in Python? I was hoping there would be something similar to matplotlib.pyplot.arrow, but I can't find anything. Is the only way to do it using matplotlib.patches with draw_artist or something similar? I would hope that there is a simpler method, but the documentation doesn't offer much help. Thanks for any advice! Have you seen the matplotlib ellipse demo ? Here they use matplotlib.patches.Ellipse . The matplotlib ellipse demo is nice. But I could not implement it in my code without a for