Rank: 72 based on 757 downloads (last 30 days) and 13 files submitted
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Quan Wang

E-mail
Company/University
Rensselaer Polytechnic Institute

Personal Profile:

http://www.ecse.rpi.edu/sites/sampl/quan/

Professional Interests:
Computer Vision, Machine Learning, Biomedical Image Analysis

 

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Files Posted by Quan View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
20 May 2014 Screenshot Pair-wise Euclidean Distance Matrix Computing the distance matrix without loops Author: Quan Wang data, distance, matrix 15 1
  • 3.0
3.0 | 1 rating
07 May 2014 Screenshot Circle Hough Transform Hough transform for circles in binary images Author: Quan Wang image processing, computer vision, filtering, image analysis 29 0
  • 5.0
5.0 | 1 rating
28 Apr 2014 Screenshot Active geometric shape models The active geometric shape model is a novel approach for fitting geometric shapes in images. Author: Quan Wang image processing, mathematics, optimization, signal processing, computer vision, shape model 87 2
  • 5.0
5.0 | 3 ratings
24 Apr 2014 Screenshot Kernel PCA and Pre-Image Reconstruction standard PCA, Gaussian kernel PCA, polynomial kernel PCA, pre-image reconstruction Author: Quan Wang signal processing, large data, dimension reduction, machine learning, pattern recognition, pca 102 8
  • 4.5
4.5 | 5 ratings
25 Mar 2014 Screenshot Remove image white margin This script removes the wide margins of images generated when saving Matlab figures Author: Quan Wang image processing 12 0
Comments and Ratings by Quan View all
Updated File Comments Rating
18 Jun 2014 Kernel PCA and Pre-Image Reconstruction standard PCA, Gaussian kernel PCA, polynomial kernel PCA, pre-image reconstruction Author: Quan Wang

Hi Cheung,

If you compute ||a-b||, you will have to use loops. MATLAB loops are slow, and distanceMatrix avoids using loops, thus is very fast.

如果用||a-b||,就需要是用MATLAB循环,而MATLAB循环非常慢。我的distanceMatrix就是一个巧妙避免使用循环的方法,因此很快。

07 May 2014 Rotate X-axis tick labels Rotate x-tick labels to any angle, preserving font settings and coping with resize, zoom, pan etc Author: Ben Tordoff

Useful

05 May 2014 Rotate Tick Label ROTATETICKLABEL rotates tick labels. Author: Andrew Bliss

Very very useful!

24 Apr 2014 Kernel PCA and Pre-Image Reconstruction standard PCA, Gaussian kernel PCA, polynomial kernel PCA, pre-image reconstruction Author: Quan Wang

Dear all,

We have updated the code and the document. The code now generates exactly the same results as shown in the document. I am sorry for the confusion in previous versions of this package. The current version has lots of significant improvements.

03 Mar 2014 Particle Swarm Optimization [xMin,yMin] = pso(fun,np,lb,ub); Author: Yan Ou

Very elegant implementation.

Comments and Ratings on Quan's Files View all
Updated File Comment by Comments Rating
18 Jun 2014 Kernel PCA and Pre-Image Reconstruction standard PCA, Gaussian kernel PCA, polynomial kernel PCA, pre-image reconstruction Author: Quan Wang Wang, Quan

Hi Cheung,

If you compute ||a-b||, you will have to use loops. MATLAB loops are slow, and distanceMatrix avoids using loops, thus is very fast.

如果用||a-b||,就需要是用MATLAB循环,而MATLAB循环非常慢。我的distanceMatrix就是一个巧妙避免使用循环的方法,因此很快。

17 Jun 2014 Kernel PCA and Pre-Image Reconstruction standard PCA, Gaussian kernel PCA, polynomial kernel PCA, pre-image reconstruction Author: Quan Wang Cheung

您好,请问在distanceMatrix函数中D=XX1+XX2-2*(X*X')起什么作用?如果使用gaussian的话,distance不应该直接就是||a-b||吗?请赐教,非常感谢!

21 May 2014 Pair-wise Euclidean Distance Matrix Computing the distance matrix without loops Author: Quan Wang Lundgren, Jonas

Dear Quan Wang,

It is a widespread misunderstanding that MATLAB loops are slow in general. Loops with simple math operations can be very fast. Waste of memory is always slow and so is the function repmat.

Compare distanceMatrix(X) with distmat(X) below. X = rand(1000,3).

I am sure you will reply with something even faster. I look forward to update the rating.

Kind regards
Jonas Lundgren

%------------------
function D = distmat(X)
%DISTMAT Compute euclidian distance matrix from coordinates

[n,dim] = size(X);
D = zeros(n);
for j = 1:n
for k = 1:dim
v = X(:,k) - X(j,k);
D(:,j) = D(:,j) + v.*v;
end
end
D = sqrt(D);

08 May 2014 Dynamic Time Warping (DTW) This package implements Dynamic Time Warping (DTW). Author: Quan Wang ryphodoras

great job!

28 Apr 2014 Circle Hough Transform Hough transform for circles in binary images Author: Quan Wang Ou, Yan

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