intersection

问题 I come across this math problem which is needed to complete my application, so I'm asking for help. Given 2 (or more, but basically for 2) rectangles with 2 known points for each: Top-left(x1, y1) and Bottom-right(x2, y2) (I can find the length with these info, if it is a need to solve the problem). TL(x1, y1) +-----------------+ | | | | TL(x3, y3) | | +---------------------------+ +-----------------+ | | BR(x2, y2) +---------------------------+ BR(x4, y4) Is there anyway to determine if they

问题 I've always been told that almost all for loops can be omitted in MATLAB and that they in general slow down the process. So is there a way to do so here?: I have a cell-array ( tsCell ). tsCell stores time-arrays with varying length. I want to find an intersecting time-array for all time-arrays ( InterSection ): InterSection = tsCell{1}.time for i = 2:length{tsCell}; InterSection = intersect(InterSection,tsCell{i}.time); end 回答1: Here's a vectorized approach using unique and accumarray,

问题 My input raster consists of multiple layers, each with an image area surrounded by no data values. These layers don't overlap completely, and I am trying to output a file which consists of only the intersection of all bands (the zone which has no NoData values on any layer). The following works for a few layers, but not for the 50+ that I have in my real files (at least 3000x3000 pixels): library(raster) fin = "D:\\temp\\all_modes.pix" fout = "D:\\temp\\test.pix" inbands = stack(fin, bands =

问题 My input raster consists of multiple layers, each with an image area surrounded by no data values. These layers don't overlap completely, and I am trying to output a file which consists of only the intersection of all bands (the zone which has no NoData values on any layer). The following works for a few layers, but not for the 50+ that I have in my real files (at least 3000x3000 pixels): library(raster) fin = "D:\\temp\\all_modes.pix" fout = "D:\\temp\\test.pix" inbands = stack(fin, bands =

问题 I've a problem with the nested lists. I want to compute the lenght of the intersection of two nested lists with the python language. My lists are composed as follows: list1 = [[1,2], [2,3], [3,4]] list2 = [[1,2], [6,7], [4,5]] output_list = [[1,2]] How can i compute the intersection of the two lists? 回答1: I think there are two reasonable approaches to solving this issue. If you don't have very many items in your top level lists, you can simply check if each sub-list in one of them is present

问题 I'm sure this has already been asked and answered so I apologize in advance for that but I'm not figuring out the correct keywords to search for. Searching for "Pattern" hits way too many Q & A's to be useful. I'm working on a regression testing app. I'm displaying a form on the screen and according to which user is logged in to the app some of the fields should be read-only. So I can abstract a field object and I can abstract a user object but what pattern should I be looking at to describe

问题 I'm looking for an algorithm for intersection of two small, unsorted array in very specific condition. Type of array item is just integer or integer-like type. Significant amount of time (about 30~40%?), one or both array might be empty. Arrays are usually very small - usually 1~3 items, I don't expect more than 10. The intersection function will be called very frequently. I don't care about platform dependent solution - I'm working on x86/windows/C++ Both brute-force/sort-and-intersect

问题 Are there any open source tools or libraries (ideally in python) that are available for performing lots of intersections with 3D geometry read from an ESRI shapefile? Most of the tests will be simple line segments vs polygons. I've looked into OGR 1.7.1 / GEOS 3.2.0, and whilst it loads the data correctly, the resulting intersections aren't correct, and most of the other tools available seem to build on this work. Whilst CGAL would have been an alternative, it's license isn't suitable. The

问题 I define intersection of two lists as follows: def intersect(a, b): return list(set(a) & set(b)) For three arguments it would look like: def intersect(a, b, c): return (list(set(a) & set(b) & set(c)) Can I generalize this function for variable number of lists? The call would look for example like: >> intersect([1, 2, 2], [2, 3, 2], [2, 5, 2], [2, 7, 2]) [2] EDIT: Python can only achieve it this way? intersect([ [1, 2, 2], [2, 3, 2], [2, 5, 2], [2, 7, 2] ]) [2] 回答1: Use the *-list-to-argument

问题 I've been using Redis for a while as a backend for Resque and now that I'm looking for a fast way to perform intersect operation on large sets of data, I decided to give Redis a shot. I've been conducting the following test: — x , y and z are Redis sets, they all contain approx. 1 million members (random integers taken from a seed array containing 3M+ members). — I want to intersect x y and z , so I'm using sintersectstore (to avoid overheating caused by data retrieval from the server to the