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Updated Intersection Matrix Calculation (markdown) authored by eswiss's avatar eswiss
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Intersection-Matrix-Calculation.md
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...@@ -29,7 +29,7 @@ The boundary of a point or multipoint is empty. ...@@ -29,7 +29,7 @@ The boundary of a point or multipoint is empty.
To determine if two geometries of dimension .zero intersect, create an array that combines both array of points. Call this the original array. From that array create a set and then a new array. Compare the size of this new array to the original. If they differ, they intersect, else they do not. If they do intersect, the dimension is .zero, else .false. To determine if two geometries of dimension .zero intersect, create an array that combines both array of points. Call this the original array. From that array create a set and then a new array. Compare the size of this new array to the original. If they differ, they intersect, else they do not. If they do intersect, the dimension is .zero, else .false.
The IM for the two disjoint geometries of dimension .zero is FF0FFF0F2. The IM for two dimension .zero geometries intersecting at a set of points is either FF0FFF0F2, if the two sets of points are not identical, and FFFFFFFF2, if the two sets of points are identical. The IM for the two disjoint geometries of dimension .zero is FF0FFF0F2. The IM for two dimension .zero geometries intersecting at a set of points is either 0F0FFF0F2, if neither geometry is a subset of the other, 0FFFFF0F2, if the first geometry is a proper subset of the second, 0F0FFFFF2, if the second geometry is a proper subset of the first, and FFFFFFFF2, if the two sets of points are identical.
To determine if two geometries, one of size .one and the other of size .zero, intersect, each point must be checked to see if it lies on any of the line segments for the geometry of size .one. As soon as a point is found that does lie on a line segment, return a dimension of .zero, else return a dimension of .false. To determine if two geometries, one of size .one and the other of size .zero, intersect, each point must be checked to see if it lies on any of the line segments for the geometry of size .one. As soon as a point is found that does lie on a line segment, return a dimension of .zero, else return a dimension of .false.
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