Rank: 562 based on 232 downloads (last 30 days) and 9 files submitted
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Ged Ridgway

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UCL
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51.523, -0.1322

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Files Posted by Ged View all
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(last 30 days)
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04 Oct 2010 Group Equally Categorise data into quantiles Author: Ged Ridgway categorize, categorise, split, group, quantiles, quartiles 6 0
21 Jul 2010 DimFunc Apply a function along any dimension of an n-D array. Author: Ged Ridgway multidimensional arra..., nd, first nonsingleton di..., dim 6 1
21 Apr 2010 Unique random permutations Random sample (without replacement) from unique permutations of a vector or row-perms of a matrix Author: Ged Ridgway combinatorics, permutation, random, unique, sign flips 31 0
  • 5.0
5.0 | 1 rating
30 Mar 2010 Struct array conversion Convert in either direction between struct-array and structure of arrays Author: Ged Ridgway struct, database, spreadsheet 17 0
08 Mar 2010 Screenshot Modulation tutorial Simple illustration of the Jacobian determinant as a geometric scaling factor Author: Ged Ridgway neuroimaging, morphometry, vbm, tbm, jacobian, determinant 17 0
Comments and Ratings by Ged View all
Updated File Comments Rating
09 Jul 2014 CSVIMPORT CSVIMPORT reads the specified CSV file and stores the contents in a cell array or matrix. Author: Ashish Sadanandan

@Marcos, I had a similar problem, which seems to be fixed by adding a carriage return at the end of the csv file (e.g. using the MATLAB editor).

15 Dec 2011 MyFisher the definitive function for the Fisher's exact and conditional test for any RxC matrix Author: Giuseppe Cardillo

Seems very useful! Might be worth (if not too much trouble) also returning the p-value from the approximate Chi-square test for comparison, since it seems that neither the Statistics toolbox nor fileexchange have this for general NxM tables.

12 Aug 2010 comparedata Compares two objects recursively. Author: Andrew Diamond

Extremely useful -- thank you!

11 Aug 2010 mmtimes: matrix chain product Return matrix chain product P = M1*M2* ... *Mn Author: Bruno Luong

11 Aug 2010 mmtimes: matrix chain product Return matrix chain product P = M1*M2* ... *Mn Author: Bruno Luong

I'm glad someone has implemented this. Two comments:

Apparently an O(N*log(N)) algorithm is available:
http://en.wikipedia.org/wiki/Matrix_chain_multiplication#An_Even_More_Efficient_Algorithm
though I don't know how this compares to the current O(N^3) one for typical values of N (e.g. the constants could make N*log(N) worse until N gets above a certain level).

More importantly (for me, anyway), I think the computation of the ordering should be a separate function, and a set ordering should then be usable in a multiplication function. E.g. if I have some code which repeatedly computes a chain multiplication in a loop, where the matrices' sizes are always the same and are known in advance, but their values vary, then much better than using mmtimes(A,B,C,...) would be to find the correct ordering first, and then hard-code that ordering in the loop. Similarly, if their sizes are constant but not known in advance, then a two-function division of labour would allow the ordering to be computed on the first iteration of the loop, and then reused without recomputation in successive iterations.

Comments and Ratings on Ged's Files View all
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28 Feb 2014 Unique random permutations Random sample (without replacement) from unique permutations of a vector or row-perms of a matrix Author: Ged Ridgway Dave

15 Jan 2014 Bipolar Colormap Symmetric/diverging/bipolar cold-neutral-hot colormap Author: Ged Ridgway Zhang, ZZL

25 Oct 2013 Rice/Rician distribution Functions for Rice/Rician PDF: stats, samples, and distribution fitting. Author: Ged Ridgway Mailhe, Boris

20 Sep 2013 Rice/Rician distribution Functions for Rice/Rician PDF: stats, samples, and distribution fitting. Author: Ged Ridgway gout, hela

merci

10 Jun 2013 Rice/Rician distribution Functions for Rice/Rician PDF: stats, samples, and distribution fitting. Author: Ged Ridgway dek, kenza

c'est un travail interessant!

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