Rank: 34 based on 1188 downloads (last 30 days) and 28 files submitted

Bruno Luong

E-mail: b.luong@fogale.fr

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Files Posted by Bruno				View all 1 - 5 of 28
Updated	File	Tags	Downloads (last 30 days)	Comments	Rating
02 Feb 2010	Consecutive vector spliter Partition an input vector into smaller series of subvectors of consecutive elements Author: Bruno Luong	split vectors, array, cell	52	3	5.0 5.0 \| 3 ratings
10 Jan 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	large size, matrix, spfun, sparse, sub indexing, update	53	10	5.0 5.0 \| 4 ratings
10 Jan 2010	Min/Max selection Search for k smallest or largest elements in the array Author: Bruno Luong	max, min, quicksort, kthvalue, selection, partial sort	62	4	5.0 5.0 \| 3 ratings
14 Dec 2009	Free-knot spline approximation Least squares approximation of 1D data using free-knots spline Author: Bruno Luong	bspline, free knots, least squares, knot removal, fitting, data compression	61	0	4.0 4.0 \| 1 rating
01 Dec 2009	Min/Max filter Multidimensional non-linear min/max filtering Author: Bruno Luong	dilatation, running min, running max, erosion, pattern recognition, filtering	94	0

Comments and Ratings by Bruno		View all 1 - 5 of 43
Updated	File	Comments	Rating
13 Mar 2010	Conjugate gradient To solve Ax=b - input: A, b, x0 (initial guess), ni (number of iteration) - output: x Author: shaoying	No H1 line, no comment, no possibility to adjust convergence criteria, no error checking. Matlab has already stock PCG function. What is the use of such function here?
09 Mar 2010	ISMEMBERF Floating-point ISMEMBER (i.e., with round-off tolerance) Author: Bruno Luong	Hi Oleg, This behavior is known (but not documented) due to the use of HISTC as you have correctly pointed out. User should never rely on the threshold tolerance in order to discriminate floats through exact comparison. Please enlarge the tolerance or add point to set member to work around. Bruno
04 Mar 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	Hello H, I can't really help with memory problem. The suggestion I can give is to try on your side to increase the free largest memory block from other places. Thanks for the kind words. Bruno
01 Mar 2010	XSum Fast Sum with error compensation Author: Jan Simon	Hello Jan, I'm not sure if I interpret the TestXSum correctly, but many methods ran under 2010A 64-bit Matlab seems to get worse accuracy than 2009B 32-bit Matlab (see below). Any idea why? ------------------------------------------------------------------------ 32-bit 2009B, MSVC 2008 SP1 RANDN: Absolute results, sum estimated by Knuth2, average over 20 runs: Smaller results are better! 0 must be replied for Knuth2, but even Knuth should be exact. X = RANDN(1, 1E4): SUM : 2.0996538E-013 SUM(SORT): 1.1599255E-011 Double : 0 Long : 0 Kahan : 2.3092639E-015 Knuth : 0 Knuth2 : 0 X = RANDN(1, 1E5): SUM : 2.5210056E-012 SUM(SORT): 4.2349626E-010 Double : 0 Long : 0 Kahan : 1.2478907E-014 Knuth : 0 Knuth2 : 0 X = RANDN(1, 1E6): SUM : 1.551328E-011 SUM(SORT): 6.7532937E-009 Double : 1.0658141E-015 Long : 1.0658141E-015 Kahan : 1.3500312E-014 Knuth : 0 Knuth2 : 0 ------------------------------------------------------------------------ 64-bit 2010A, MSVC 2008 SP1 RANDN: Absolute results, sum estimated by Knuth2, average over 20 runs: Smaller results are better! 0 must be replied for Knuth2, but even Knuth should be exact. X = RANDN(1, 1E4): SUM : 2.0996538E-013 SUM(SORT): 1.1599255E-011 Double : 2.0996538E-013 Long : 2.0996538E-013 Kahan : 2.3092639E-015 Knuth : 0 Knuth2 : 0 X = RANDN(1, 1E5): SUM : 2.5210056E-012 SUM(SORT): 4.2349626E-010 Double : 3.2762681E-012 Long : 3.2762681E-012 Kahan : 1.2478907E-014 Knuth : 0 Knuth2 : 0 X = RANDN(1, 1E6): SUM : 1.551328E-011 SUM(SORT): 6.7532937E-009 Double : 2.3623414E-011 Long : 2.3623414E-011 Kahan : 1.3500312E-014 Knuth : 0 Knuth2 : 0
11 Jan 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	Thanks for the tip James.

Comments and Ratings on Bruno's Files			View all 1 - 5 of 61
Updated	File	Comment by	Comments	Rating
09 Mar 2010	ISMEMBERF Floating-point ISMEMBER (i.e., with round-off tolerance) Author: Bruno Luong	Komarov, Oleg	Well, I suggest at this point to document this behaviour and to add in the see also line the HISTC. Something like: A(i) is member of the set S if the following condition is verified at least once: k - tol <= A(i) < k + tol for k = S(1)...S(K) Best
09 Mar 2010	ISMEMBERF Floating-point ISMEMBER (i.e., with round-off tolerance) Author: Bruno Luong	Luong, Bruno	Hi Oleg, This behavior is known (but not documented) due to the use of HISTC as you have correctly pointed out. User should never rely on the threshold tolerance in order to discriminate floats through exact comparison. Please enlarge the tolerance or add point to set member to work around. Bruno
08 Mar 2010	ISMEMBERF Floating-point ISMEMBER (i.e., with round-off tolerance) Author: Bruno Luong	Komarov, Oleg	Dear Bruno, I want to bring this case to your attention: tf = ismemberf(2.8, 2.9, 'tol',.1) --> 1 tf = ismemberf(3, 2.9, 'tol',.1) --> 0 It's following histc behaviour on line 287 (lowB <= x < uppB), is this meant? Regards Oleg
04 Mar 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	Luong, Bruno	Hello H, I can't really help with memory problem. The suggestion I can give is to try on your side to increase the free largest memory block from other places. Thanks for the kind words. Bruno
03 Mar 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	H	This seems to have one problem though: Before I used A(:,indexes)=0, it just took a lot of time. No I tried [I J]=find(A); idxofzero = ismember(J,indexes); A=setsparse(A,I(idxofzero),J(idxofzero),0); And I get "out of memory error". I tried it several times with both methods and got the same result. Am I missing something here? My sparse matrix is about 55,000 x 55,000 and it has 4,060,200 nnz elements. The indexes hold about 1/100 of the columns.

Top Tags Applied by Bruno	1 - 5 of 150
array, eval, hist, histc, histogram

Files Tagged by Bruno				View all 1 - 5 of 31
Updated	File	Tags	Downloads (last 30 days)	Comments	Rating
02 Feb 2010	Consecutive vector spliter Partition an input vector into smaller series of subvectors of consecutive elements Author: Bruno Luong	split vectors, array, cell	52	3	5.0 5.0 \| 3 ratings
10 Jan 2010	Sparse sub access This package allows to retrieve and assign values of sparse matrix in one shot. Author: Bruno Luong	large size, matrix, spfun, sparse, sub indexing, update	53	10	5.0 5.0 \| 4 ratings
10 Jan 2010	Min/Max selection Search for k smallest or largest elements in the array Author: Bruno Luong	max, min, quicksort, kthvalue, selection, partial sort	62	4	5.0 5.0 \| 3 ratings
14 Dec 2009	Free-knot spline approximation Least squares approximation of 1D data using free-knots spline Author: Bruno Luong	bspline, free knots, least squares, knot removal, fitting, data compression	61	0	4.0 4.0 \| 1 rating
01 Dec 2009	Min/Max filter Multidimensional non-linear min/max filtering Author: Bruno Luong	dilatation, running min, running max, erosion, pattern recognition, filtering	94	0

Currently Watching
Type	Description
File	Spline derivative
File	Min/Max selection
File	Multiple same-size linear solver
File	Min/Max filter
File	Consecutive vector spliter
File	Vectorized FIND with 'FIRST' option
File	Cubed sphere
File	Plot earth
File	Costantini phase unwrapping

Files Matching Bruno's Watch List				View all 1 - 5 of 9
Updated	File	Tags	Downloads (last 30 days)	Comments	Rating
02 Feb 2010	Consecutive vector spliter Partition an input vector into smaller series of subvectors of consecutive elements Author: Bruno Luong	split vectors, array, cell	52	3	5.0 5.0 \| 3 ratings
10 Jan 2010	Min/Max selection Search for k smallest or largest elements in the array Author: Bruno Luong	max, min, quicksort, kthvalue, selection, partial sort	62	4	5.0 5.0 \| 3 ratings
01 Dec 2009	Min/Max filter Multidimensional non-linear min/max filtering Author: Bruno Luong	dilatation, running min, running max, erosion, pattern recognition, filtering	94	0
29 Aug 2009	Costantini phase unwrapping Implementation of Costantini's 2D unwrapping method based on network programming Author: Bruno Luong	interferometry, network flow, phase unwrapping, sar	48	0	4.0 4.0 \| 1 rating
20 Aug 2009	Plot earth Plot earth in 3D Author: Bruno Luong	map, earth, texture, graphic, sphere, mercator	59	0	5.0 5.0 \| 1 rating

Comments and Ratings Matching Bruno's Watch List			1-5 of 12
Date	File	Comment by	Comments	Rating
23 Feb 2010	Consecutive vector spliter Partition an input vector into smaller series of subvectors of consecutive elements	John D'Errico	As you would expect of all of Bruno's submissions, it does exactly what it says it will do. Superb documentation.	5
23 Feb 2010	Consecutive vector spliter Partition an input vector into smaller series of subvectors of consecutive elements	Tom Toner	Thanks a lot for such a great function!	5
10 Jan 2010	Min/Max selection Search for k smallest or largest elements in the array	Jan Simon	Thanks! Efficient (see note), really tricky+fast usage of shared values for columns accessing, sophisticated sorting, good documentation and an installation method, which considers different Matlab versions. Excellent for teaching using shared data copies in Mex files! Although this function is not designed to work on small arrays, for this case the VARARGIN/VARARGOUT overhead might be avoidable. E.g. MINK: function varargout=mink(varargin) nout = cell(1, max(1, nargout)); [nout{:}] = minmaxk(@minkmex, varargin{:}); vargargout=nout; 10% faster for MINK(1:100, 10): function [V, Idx] = mink(list, k) if nargin == 1, k = 1; end if nargout == 2, [V, Idx] = minmaxk(@minkmex, list, k); else, V = minmaxk(@minkmex, list, k); end For large inputs, this is obviously negligible. But there are no drawbacks. NOTE: I've compared this with dull brute force search of the K.th smallest/largest elements. I'll send you the source by mail and be glad for your comments.	5
16 Dec 2009	Costantini phase unwrapping Implementation of Costantini's 2D unwrapping method based on network programming	Nickolai Ushakov		4
05 Dec 2009	Min/Max selection Search for k smallest or largest elements in the array	Matt Fetterman		5

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