
NDIMENSIONAL CONVEX HULL: QUICKER HULL ALGORITHM 1.0 File ID: 79315 


 NDIMENSIONAL CONVEX HULL: QUICKER HULL ALGORITHM 1.0 License: Freeware File Size: 10.0 KB Downloads: 21
Submit Rating: 



NDIMENSIONAL CONVEX HULL: QUICKER HULL ALGORITHM 1.0 Description 

Description: The Matlab convhulln is a gateway to the quickhull algorithm ( see www.qhull.org ). In my opinion, one weak point of this mex routine is that it processes all the points without performing any preliminary filtering. In many cases it would be faster if only the point that can be part of the convhull were send to the quick hull algorithm.
Here is proposed an algorithm that can reduce the number of points before sending them to the mex routine. For large models in dimensions lower than 6 the speed improvement can be even of several factors.
Unfortunately filtering points costs time and for high dimensions becomes unadvantageous.But no problem in these cases the algorithm just switch to the normal convhulln.
A test to compare performances is provided. Acknowledgments about bugs or incorrect timing are greatly appreciated.
License: Freeware Related: and for, preliminary, Algorithm, all the, algorithmhere, greatly, be even, Bugs, can be, Sending, unadvantageousbut, faster, part, timing greatly, compare performances, Time, mex routine O/S:BSD, Linux, Solaris, Mac OS X File Size: 10.0 KB Downloads: 21


More Similar Code 

This builds a navigation GUI for navigating ndimensional convex Pareto surfaces interactively. It requires linprog from the optimization toolbox, but can probably be replaced easily with a free version. The linear programs solved during navigation are very small and easy. It is assumed that all objectives are 'minimize' objectives. Thus normal navigation mode is to pull sliders downward.
mnav(pSurf) is how you call it. pSurf...
I have looked far and wide for code for fast sorting of n dimensional arrays by the first element, for example if I had the array: ray = [[1,2,3,7,5][10,11,12,13,14]]
I would want it to come out as ray =...
Three ways to calculate a distance matrix out of a list of ndimensional points using scipy.
This function is an implementation of Ndimensional convolution for the special case when the convolution kernel is separable.
A continuous function f(x1, x2, ... xN) is considered separable if there exist N functions f1, f2, ... fN...
The class ndSparse defined in this submission will give a lot of the functionality of Ndimensional sparse arrays for N possibly greater than 2. However, it should really be thought of as a way of starting with an ordinary MATLAB sparse matrix and...
Many image processing applications require an extensive usage of FFT2 routine (or, in the most general case, a Ndimensional FFT) of matrices having the same dimensions. In these cases MATLAB FFT2 can result extremely inefficient. In general the...
This program computes the projection of any ndimensional vector y onto the canonical simplex Dn defined by Dn:={x: x ndimensional vector, 0
HISTCND Histogram count for n dimensional data. N = HISTCND(X,EDGES), for row vectors X, counts the number of values in X that fall between the grid defined by the cell array of EDGES, each of whose element is a vector that...
function [i,i_] = fgridmin(y) % Search an Ndimensional array y for points that may be proximate to a global minimum % of the interpolated array; return the proximate points' ND subscripts (i) in y. Also % optionally return the...
This implementation includes modules for very fast loading and saving of ndimensional, possibly colored and bulky point clouds. The proposed functions can also be used to load and save matrices in ASCII format.
USAGE  
User Review for NDIMENSIONAL CONVEX HULL: QUICKER HULL ALGORITHM 
