Rank: 312 based on 273 downloads (last 30 days) and 11 files submitted
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Andrew Knyazev

E-mail
Company/University
University of Colorado Denver

Personal Profile:

http://math.ucdenver.edu/~aknyazev/

Professional Interests:
matrix computations, numerical PDEs, data mining

 

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Files Posted by Andrew View all
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06 Jan 2012 Screenshot Newton's method done right Newton's method for solving systems of nonlinear equations, including nonsquare and inconsistent Author: Andrew Knyazev mathematics, physics, modeling, matrix, newton, nonlinear 75 0
08 Dec 2011 Screenshot ODE Tutorial Demo Advanced examples of using the MATLAB Symbolic Math Toolbox for Ordinary Differential Equations Author: Andrew Knyazev ode, symbolic, movies, demo, physics, mathematics 28 0
17 Oct 2011 Screenshot lobpcg.m LOBPCG solves Hermitian partial generalized eigenproblems using preconditioning, competes with eigs Author: Andrew Knyazev linear algebra, symmetric, partial, eigenproblems, preconditioning, eigenproblem 44 6
  • 4.5
4.5 | 2 ratings
14 Sep 2011 Screenshot Best polynomial approximation in uniform norm For a given function on an interval, the code calculates the min-max approximation by a polynomial. Author: Andrew Knyazev mathematics, statistics, optimization, approximation, polynomial, minimax 19 0
03 Sep 2011 Screenshot pcg.m with 'null' and 'flex' options Preconditioned Conjugate Gradients handles homogeneous equations and nonsymmetric preconditioning Author: Andrew Knyazev linear algebra, preconditioned, conjugate, gradients, mathematics, matrix 10 0
Comments and Ratings by Andrew View all
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12 Oct 2011 Newton Method in N dimensions Simple implementation of Newton's method, in n dimensions, taking input of >=n equations. Author: Kyle Drerup

Simple, general and nice! The best I have on the block so far.

Missing: limit number of steps, check for stagnation. default for the tolerance.

Cannot you just always use F_prime_X\F_X ?

12 Oct 2011 Numerical Analysis Functions 1 Functions for the Bisection, Fixed-Point, Newton-Raphson, and Muller's methods. Author: Jonathan Lister

Well written.

12 Oct 2011 Newton's Method Finds better successive approximations for the root of a function using Newton's Method. Author: Harmon Amakobe

"Number of iterations will be increased accordingly in order to meet the set tolerance value" - in other words the "ite" parameter is always ignored. The code never stops if the tolerance is not met.

12 Oct 2011 newton raphson it's a homework study for numerical analysis class Author: osman onur gürler

It could have been useful for English-speaking users, if it was in English.

12 Oct 2011 Newton-Raphson Iterative Solver for Systems of Equations An N-R iterative root-finder for systems of N equations and N unknowns. Author: John Fuller

Incomplete description. The function is hard-coded for no more than 8 equations. Quoting the code: "Holy crap! More than 8 equations to solve??"
Comments and Ratings on Andrew's Files View all
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12 Sep 2011 Laplacian in 1D, 2D, or 3D Sparse (1-3)D Laplacian on a rectangular grid with exact eigenpairs. Author: Andrew Knyazev Smart, Mr
20 Aug 2011 matlab2hypre and hypre2matlab Read and write files with sparse matrices and vectors in hypre format Author: Andrew Knyazev Knyazev, Andrew

Similar functions for PETSc are available in the PETSc distribution in the directory bin/matlab , see http://www.mcs.anl.gov/petsc/
31 Jul 2011 matlab2hypre and hypre2matlab Read and write files with sparse matrices and vectors in hypre format Author: Andrew Knyazev Knyazev, Andrew

Hypre does NOT support complex arithmetic. A complex valued matrix in MATLAB will be transformed into a real matrix by the matlab2hypre code, by simply dropping the imaginary part. No warning is generated by the code in this case.

25 Jul 2011 lobpcg.m LOBPCG solves Hermitian partial generalized eigenproblems using preconditioning, competes with eigs Author: Andrew Knyazev Knyazev, Andrew

"I encounter some severe differences in memory requirements comparing lobpcg.m with lobpcg from hypre/ij. Is there a way to use hypre with the same requirements as lobpcg.m?"

High memory requirements in hypre/ij in these tests come from hypre BoomerAMG preconditioning, not from the LOBPCG. For my full answer please see my reply at

http://www.mathworks.com/matlabcentral/answers/9534-memory-requirements-of-lobpcg-matlab-and-hypre-implementation-differences
15 Jun 2011 lobpcg.m LOBPCG solves Hermitian partial generalized eigenproblems using preconditioning, competes with eigs Author: Andrew Knyazev Elias

I encounter some severe differences in memory requirements comparing lobpcg.m with lobpcg from hypre/ij. Is there a way to use hypre with the same requirements as lobpcg.m? For full explanation see

http://www.mathworks.com/matlabcentral/answers/9534-memory-requirements-of-lobpcg-matlab-and-hypre-implementation-differences
Top Tags Applied by Andrew
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mathematics, linear algebra, matrix, statistics, angle
Files Tagged by Andrew View all
  • 1 - 5 of
  • 11
Updated   File Tags Downloads
(last 30 days) 		Comments Rating
06 Jan 2012 Screenshot Newton's method done right Newton's method for solving systems of nonlinear equations, including nonsquare and inconsistent Author: Andrew Knyazev mathematics, physics, modeling, matrix, newton, nonlinear 75 0
08 Dec 2011 Screenshot ODE Tutorial Demo Advanced examples of using the MATLAB Symbolic Math Toolbox for Ordinary Differential Equations Author: Andrew Knyazev ode, symbolic, movies, demo, physics, mathematics 28 0
17 Oct 2011 Screenshot lobpcg.m LOBPCG solves Hermitian partial generalized eigenproblems using preconditioning, competes with eigs Author: Andrew Knyazev linear algebra, symmetric, partial, eigenproblems, preconditioning, eigenproblem 44 6
  • 4.5
4.5 | 2 ratings
14 Sep 2011 Screenshot Best polynomial approximation in uniform norm For a given function on an interval, the code calculates the min-max approximation by a polynomial. Author: Andrew Knyazev mathematics, statistics, optimization, approximation, polynomial, minimax 19 0
03 Sep 2011 Screenshot pcg.m with 'null' and 'flex' options Preconditioned Conjugate Gradients handles homogeneous equations and nonsymmetric preconditioning Author: Andrew Knyazev linear algebra, preconditioned, conjugate, gradients, mathematics, matrix 10 0

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