Rank: 365 based on 251 downloads (last 30 days) and 18 files submitted
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Tim Davis

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Company/University
Univ of Florida
Lat/Long
29.648483, -82.34458

Personal Profile:

Professor, Univ of Florida. Member of the SIAM Council ( http://www.siam.org/about/board.php ). Author/co-author of many built-in sparse functions in MATLAB: UMFPACK (lu), CHOLMOD (chol), QR (SuiteSparseQR), COLAMD, SYMAMD, AMD, ETREE, DMPERM, SYMBFACT, and sparse matrix multiply. See also http://www.cise.ufl.edu/~davis . Much of this work is in my book "Direct Methods for Sparse Linear Systems", SIAM, Sept. 2006, which presents the theory and practice of sparse matrix algorithms, and discusses how MATLAB performs its sparse matrix computations. Additional features, latest versions, and better performance for sparse matrix operations in MATLAB can be obtained from my files posted at http://www.cise.ufl.edu/research/sparse . Note that The MathWorks now requires files posted here to appear under a BSD License. I'm unable to change the licensing of some of my code (GNU GPL and LGPL). You can now find UMFPACK, CHOLMOD, SuiteSparse, etc. on my web page.

Professional Interests:
numerical linear algebra, sparse matrix algorithms, computational science, mathematical poetry

 

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Files Posted by Tim View all
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(last 30 days)
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09 Jul 2013 sparseinv: sparse inverse subset Computes a subset of inv(A) for a real sparse matrix A, using Takahashi's equations. Author: Tim Davis sparse, inverse 34 1
  • 5.0
5.0 | 1 rating
06 Sep 2011 Don't let that INV go past your eyes; to solve that system, FACTORIZE! A simple-to-use object-oriented method for solving linear systems and least-squares problems. Author: Tim Davis factorization, backslash, mldivide, mrdivide, inv, pinv 32 11
  • 5.0
5.0 | 9 ratings
04 Feb 2010 Screenshot MATLAB Primer, 7th Edition, CRC Press, 2005 This is not the book itself, but a set of files printed in the book, "MATLAB Primer, 7th Ed." Author: Tim Davis matlab primer, book program, companion software 15 0
10 Sep 2009 Gaussian Elimination Example (with partial pivoting): GEE, it's simple! A set of simple functions that illustrate Gaussian Elimination with partial pivoting Author: Tim Davis linear algebra, gaussian elimination, tutorial, partial pivoting, mathematics 17 2
  • 5.0
5.0 | 2 ratings
27 May 2009 LINFACTOR: uses LU or CHOL to factorize a matrix, or previously computed factors to solve Ax=b A simple M-file to solve Ax=b using LU or CHOL. Author: Tim Davis linear algebra, linfactor, linsolve, lu, chol, inv 17 3
  • 5.0
5.0 | 3 ratings
Comments and Ratings by Tim View all
Updated File Comments Rating
07 Sep 2011 Don't let that INV go past your eyes; to solve that system, FACTORIZE! A simple-to-use object-oriented method for solving linear systems and least-squares problems. Author: Tim Davis

Comment from the author: I have addressed Ben's comment about uminus in this update (Sept 2011). You can now do -inverse(A)*b, or -2*inverse(A)*b, which you could not do in the previous version.

22 Mar 2010 Don't let that INV go past your eyes; to solve that system, FACTORIZE! A simple-to-use object-oriented method for solving linear systems and least-squares problems. Author: Tim Davis

-inverse(A)*b can also be done as -(inverse(A)*b), which is more natural than inverse(A)*(-b).

12 Mar 2010 VIDEO TUTORIAL: Serial communication (TX and RX) using SERIAL Matlab function. VIDEO TUTORIAL: Serial communication (TX and RX) using SERIAL Matlab function.(Narration in Spanish) Author: Diego Barragán

Minor comment: the downloaded filename includes non-ascii characters. This causes the MATLAB "unzip" function to fail. A video in Spanish is fine (there should be more), but I suggest that you change the filename so that MATLAB can handle the file properly.

12 Mar 2010 Tamper-proof digital files An example of a self-embedding scenario Author: Abbas Cheddad

"wanna" is not grammatically correct, and is not a good example for secondary students.

12 Mar 2010 Complement Coding Complement Coding can be used to preprocess and normalize neural network input. Author: Massimiliano Versace

The "unzip" function in MATLAB cannot handle this file. It returns an error:

warning: ERROR: Error using ==> extractArchive>copyStreams at 174
Unable to write file "./complement_coding_icon_3_elaborated.pdf".
The entry may be password-protected or encrypted.

I was able to unzip it on my Mac, via the Unix "unzip" command. The MATLAB "unzip" fails.

Also, the zip file contains yet another copy of itself (complement.zip). That file includes still another copy of the code.

Please rezip the file and repost it. You should exclude the nested zip file.

Comments and Ratings on Tim's Files View all
Updated File Comment by Comments Rating
20 Jun 2014 spok: checks if a MATLAB sparse matrix is OK Useful for mexFunction authors only Author: Tim Davis Farrahi Moghaddam, Reza

Great work. The option '-largeArrayDims' can be added to the mex commands in spok_install.m and spok_test.m to avoid errors such as 'LINK : fatal error LNK1181: cannot open input file "kernel32.lib"' and 'Function "mxGetJc_700" is obsolete.
(64-bit mex files using sparse matrices must be rebuilt with the "-largeArrayDims" option. See the
R2006b release notes for more details.).'

10 Jun 2014 LINFACTOR: uses LU or CHOL to factorize a matrix, or previously computed factors to solve Ax=b A simple M-file to solve Ax=b using LU or CHOL. Author: Tim Davis Amin

10 Jan 2014 sparseinv: sparse inverse subset Computes a subset of inv(A) for a real sparse matrix A, using Takahashi's equations. Author: Tim Davis Agamennoni, Gabriel

Great submission! It's (almost) exactly what I was looking for. Is there a way to perform low-rank updates of the inverse subset (e.g. like cholupdate)?

11 Feb 2012 PageRank demo A graphical demo of a random web surfer (aka Google's PageRank) Author: Tim Davis Charles

11 Dec 2011 LINFACTOR: uses LU or CHOL to factorize a matrix, or previously computed factors to solve Ax=b A simple M-file to solve Ax=b using LU or CHOL. Author: Tim Davis N. Yildirim

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