ellipse

I am writing an iPad app in which I am rendering XML objects that represent shapes into graphics on the screen. One of the objects I am trying to render is arcs. Essentially these arcs provide me with a bounding rectangle as well as a start and end angle. Given attributes: x y width height startAngle endAngle With these values I need to draw the arc (which is essentially part of an ellipse). I can not use the following: UIBezierPath *arc = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(x, y, width, height)]; [UIColor blackColor] setStroke]; [arc stroke]; because it draws a full ellipse.

I have a set of 2D points. I need to find a minimum area ellipse enclosing all the points. Could someone give an idea of how the problem has to be tackled. For a circle it was simple. The largest distance between the center and the point. But for an ellipse its quite complicated which I do not know. I have to implement this in c++. These don't go as far as giving you C++ code, but they include in-depth discussion of effective algorithms for what you need to do. https://www.cs.cornell.edu/cv/OtherPdf/Ellipse.pdf http://www.stsci.edu/~RAB/Backup%20Oct%2022%202011/f_3_CalculationForWFIRSTML

Forum I've got a set of data that apparently forms an ellipse in 3D space (not an ellipsoid, but a curve in 3D). Being inspired by following thread http://au.mathworks.com/matlabcentral/newsreader/view_thread/65773 and with the help from someone ,I manage to get the optimization code running and outputs a set of best parameters x (vector). However, when I try to use this x to replicate the ellipse,the outcomes is a strange straight line in the space. I have been stacked on this for days., still don't know what went wrong....pretty much devastated... I hope someone can shed some light on this.

So as the title states, I would want to move the ellipse on mouse drag. I have declared ellipses first and drew them through ArrayLists (since I have 8 ellipses which carry different color information. Four are white and the other are red). I tried doing what I did for the rectangles: public void mousePressed(MouseEvent e) { x = e.getX(); y = e.getY(); } public void mouseDragged(MouseEvent e) { if(e.getSource()==MainPane) { int dx = e.getX() - x; int dy = e.getY() - y; Point p = getLocation(); if(el1.getBounds().contains(x,y)) { el1.x += dx; el1.y += dy; } x += dx; y += dy; } } But this doesn

Does anyone know if it is possible to calculate the overlapping area of two ellipses using matplotlib.patches.Ellipse . I have to ellipses like this: And i would like to calculate the ratio between the overlap area and the are of the individual ellipses. Is this possible using only the Ellipse from matplotlib.patches You cannot compute the area of the intersect with matplotlib (at least not to my knowledge), but you can use shapely to do so and then use matplotlib to visualise the result. Here a quick demo: from matplotlib import pyplot as plt from shapely.geometry.point import Point from

I'm getting ellipses as level curves of a fit dataset. After selecting a particular ellipse, I would like to report it as a center point, semi-major and minor axes lengths, and a rotation angle. In other words, I would like to transform (using mathematica) my ellipse equation from the form: Ax^2 + By^2 + Cx + Dy + Exy + F = 0 to a more standard form: ((xCos[alpha] - ySin[alpha] - h)^2)/(r^2) + ((xSin[alpha] + yCos[alpha] - k)^2)/(s^2) = 1 where (h,k) is the center, alpha is the rotation angle, and r and s are the semi-axes The actual equation I'm attempting to transform is 1.68052 x - 9.83173