intersection

I have two linear fits that I've gotten from lm calls in my R script. For instance... fit1 <- lm(y1 ~ x1) fit2 <- lm(y2 ~ x2) I'd like to find the (x,y) point at which these two lines ( fit1 and fit2 ) intersect, if they intersect at all. One way to avoid the geometry is to re-parameterize the equations as: y1 = m1 * (x1 - x0) + y0 y2 = m2 * (x2 - x0) + y0 in terms of their intersection point (x0, y0) and then perform the fit of both at once using nls so that the returned values of x0 and y0 give the result: # test data set.seed(123) x1 <- 1:10 y1 <- -5 + x1 + rnorm(10) x2 <- 1:10 y2 <- 5 - x1

How does one compute the area of intersection between a triangle (specified as three (X,Y) pairs) and a circle (X,Y,R)? I've done some searching to no avail. This is for work, not school. :) It would look something like this in C#: struct { PointF vert[3]; } Triangle; struct { PointF center; float radius; } Circle; // returns the area of intersection, e.g.: // if the circle contains the triangle, return area of triangle // if the triangle contains the circle, return area of circle // if partial intersection, figure that out // if no intersection, return 0 double AreaOfIntersection(Triangle t,

I have a set of 2d points distributed randomly. I need to perform a time intensive operation on a small subset of these points but I need to first figure out what points I need to perform this time intensive operation on. To determine what points I need they must pass a series of geometric criteria. The most basic criteria is are they within a certain distance of a specific point. The second most basic criteria is whether they are contained within a circle sector (a 2-D cone) extending out from that specific point. (Edit: This operation is called regularly with a different specific point each

Is there any function that will give me the intersection point of a Polygon and Line2D ? I have a Polygon and a line segment that I know intersect I want the actual value of the intersection point not a boolean answer. Here you are. The interesting methods are getIntersections and getIntersection. The former parses over all polygon segments and checks for intersections, the latter does the actual calculation. Do keep in mind that the calculation can be seriously optimized and doesn't check for division by 0. This will also work only for polygons. It could be adapted to work with other shapes

Need a Java function to find intersection of two strings. i.e. characters common to the strings. Example: String s1 = new String("Sychelless"); String s2 = new String("Sydney"); Using HashSet<Character> : HashSet<Character> h1 = new HashSet<Character>(), h2 = new HashSet<Character>(); for(int i = 0; i < s1.length(); i++) { h1.add(s1.charAt(i)); } for(int i = 0; i < s2.length(); i++) { h2.add(s2.charAt(i)); } h1.retainAll(h2); Character[] res = h1.toArray(new Character[0]); This is O(m + n) , which is asymptotically optimal. Extract the characters String.toCharArray Put them in a Set Find the

How do I calculate the intersection points of two circles. I would expect there to be either two, one or no intersection points in all cases. I have the x and y coordinates of the centre-point, and the radius for each circle. An answer in python would be preferred, but any working algorithm would be acceptable. Jacob Intersection of two circles Written by Paul Bourke The following note describes how to find the intersection point(s) between two circles on a plane, the following notation is used. The aim is to find the two points P 3 = (x 3 , y 3 ) if they exist. First calculate the distance d