Rank: 165 based on 285 downloads (last 30 days) and 17 files submitted
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Tristan Ursell

E-mail
Company/University
Stanford University

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Professional Interests:
physics, biophysics, genetic algorithms

 

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Files Posted by Tristan View all
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(last 30 days)
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24 Jul 2013 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell points, distance, neighbor, 2d, point, contour 37 9
  • 4.66667
4.7 | 4 ratings
09 Jul 2013 Screenshot 1D Non-derivative Peak Finder Up-sample and filter noisy data to find peaks without using derivatives. Author: Tristan Ursell extrema, min, local, peak, location, finding 89 5
  • 5.0
5.0 | 2 ratings
28 May 2013 Screenshot Frechet Distance Calculator Estimate the similarity between curves in space using the scalar Frechet Distance. Author: Tristan Ursell curve, curves, path, space, space curve, distance 17 0
28 May 2013 Screenshot Find Image Extrema Find local maxima, local minima, saddle points, and flat regions in an image. Author: Tristan Ursell image, maximum, maxima, local, saddle, point 31 1
  • 5.0
5.0 | 1 rating
12 Feb 2013 Screenshot Adaptive Colormap Function Creates a Colormap Specific to Data Easily design and fit a colormap to the values in your data! Author: Tristan Ursell color, red, blue, green, colormap, map 3 1
Comments and Ratings by Tristan View all
Updated File Comments Rating
23 Jul 2013 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell

@Roy -- good suggestion, I will try to implement that soon.

14 Dec 2012 Adaptive Colormap Function Creates a Colormap Specific to Data Easily design and fit a colormap to the values in your data! Author: Tristan Ursell

I'll fix the typos in the description soon.

15 Nov 2012 Image Noise Reduction by Local Statistics Reduce image noise by measuring local pixel statistics and remapping intensities. Author: Tristan Ursell

if you like this function, please consider rating it! (if you don't, please tell me why)

23 Mar 2012 Copy Files in Batches using Search Terms Copy files matching search terms, from sub-directories matching search terms into a new directory. Author: Tristan Ursell

@Jan, thanks. I 'char'-ed it just to be safe :)

15 Mar 2012 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell

Here's a partial fix of the problem you mention Catherine. There is no general solution to your problem without solving the TSP -- which is NP hard :) There is however another level of fix that would require time to write, where you sample N-points ahead in the contour and search exhaustively for the shortest local N-path. That would likely get rid of most crossings and

Comments and Ratings on Tristan's Files View all
Updated File Comment by Comments Rating
23 Jul 2013 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell Ursell, Tristan

@Roy -- good suggestion, I will try to implement that soon.

23 Jul 2013 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell Roy

This looks great, but I have a feature request:

The built-in command 'sort' has the optional syntax

[y,i]=sort(x)

where y is a sorted version of x, and x(i)=y

This is useful if you have several data vectors that all need to be re-ordered along with x.

I think adding this feature to the program would be pretty simple, but that you could do it much faster than I could.

Thanks!

17 Jun 2013 Find Image Extrema Find local maxima, local minima, saddle points, and flat regions in an image. Author: Tristan Ursell Tobias

Very valuable file, thanks for uploading!

17 Jun 2013 Create a Simulated Image of Diffraction Limited Spots with Noise Create images with diffraction-limited spots of varying size and intensity, with noise. Author: Tristan Ursell Nayak, Abani

sir
i am sorry to put you in trouble. i myself figured it out how to do that. i had not checked the imwrite function at that time.
thank you sir for your beautiful code. it will help me a lot in my project.

17 Jun 2013 Create a Simulated Image of Diffraction Limited Spots with Noise Create images with diffraction-limited spots of varying size and intensity, with noise. Author: Tristan Ursell Nayak, Abani

sir
i am new to the matlab. i am doing a similar project. this program was very helpful to me. while running the examples given above by you. i am getting the spots enclosed with red circles. i want the image as it is but without the red circle. i did some modification with your code but i couldn't find any solutions to my problem.
so i request yo to kindly help me to get the spots but without red circles enclosing the spot.
Thank you

Top Tags Applied by Tristan
image, 2d, matrix, noise, path
Files Tagged by Tristan View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
24 Jul 2013 Connect Randomly Ordered 2D Points into a Minimal Nearest-Neighbor Closed Contour Connects randomly ordered 2D points into a minimal nearest neighbor contour. Author: Tristan Ursell points, distance, neighbor, 2d, point, contour 37 9
  • 4.66667
4.7 | 4 ratings
09 Jul 2013 Screenshot 1D Non-derivative Peak Finder Up-sample and filter noisy data to find peaks without using derivatives. Author: Tristan Ursell extrema, min, local, peak, location, finding 89 5
  • 5.0
5.0 | 2 ratings
28 May 2013 Screenshot Frechet Distance Calculator Estimate the similarity between curves in space using the scalar Frechet Distance. Author: Tristan Ursell curve, curves, path, space, space curve, distance 17 0
28 May 2013 Screenshot Find Image Extrema Find local maxima, local minima, saddle points, and flat regions in an image. Author: Tristan Ursell image, maximum, maxima, local, saddle, point 31 1
  • 5.0
5.0 | 1 rating
12 Feb 2013 Screenshot Adaptive Colormap Function Creates a Colormap Specific to Data Easily design and fit a colormap to the values in your data! Author: Tristan Ursell color, red, blue, green, colormap, map 3 1

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