1,939 reputation
1524
bio website uclue.com
location Knoxville, TN
age 62
visits member for 3 years, 2 months
seen just now

Enjoys programming in Prolog.


1d
reviewed No Action Needed How can calculations cause an arithmetic overflow even if the final value fits?
1d
reviewed Reject numerical-limitations tag wiki excerpt
Mar
22
comment Danger of complex arithmetics in scientific computing
@WolfgangBangerth: I was thinking about a user of libraries (developing software using one or more linear algebra packages) who trusts the third-party software but is aware that these are inconsistent in their treatment of complex inner products. In such a case one might make an effort to maintain compatibility by calling various libraries through "wrappers" that would conjugate or swap arguments as necessary. A fairly small set of test routines would then suffice to maintain consistency as the "outer" software evolves.
Mar
21
reviewed Reviewed Can Gauss-Seidel/SOR (preconditioned?) be apllied to all zero diagonal system?
Mar
21
comment Can Gauss-Seidel/SOR (preconditioned?) be apllied to all zero diagonal system?
Think about how the information is flowing in determining your solution. In an elliptic problem, boundary value information flow to the interior of your domain and discretely this corresponds to solving a system of simultaneous equations. In the discretized equation shown above the information would seem to flow naturally in one direction or the other (increasing $x$ or decreasing). It doesn't seem a compelling opportunity to rewrite the solution procedure/discretization to make it fit with solving a simultaneous system, as this would normally be more costly.
Mar
21
reviewed No Action Needed Integrating radial Schrodinger equation with Lennard-Jones potential using Runge-Kutta with adaptive step size ends up with a step-size of zero
Mar
21
reviewed Close Matlab backslash command slow on diagonal matrix
Mar
21
reviewed Approve Can Gauss-Seidel/SOR (preconditioned?) be apllied to all zero diagonal system?
Mar
21
comment Danger of complex arithmetics in scientific computing
Does anybody really know which root of $-1$ is $i$ and which is $-i$? It would seem that a software developer should include a small set of test examples in their regression suite to guard against incorporating inconsistent conjugations in any lengthy chain of complex arithmetic computations.
Mar
17
revised Open source implementation of rational approximation to a function
introduced an example for illustration
Mar
14
reviewed Approve Solve steady state reaction-diffusion/Helmholtz equation numerically
Mar
6
comment Constraint containing 'max' in linear program unnecessary?
While it may be perfectly clear to you that these given values are indeed non-negative, nothing in the Question's statement promises that this is the case. It is relevant in any case to answering your Question.
Mar
6
reviewed Reviewed Using HMM for speech synthesis
Mar
6
reviewed Reviewed Constraint containing 'max' in linear program unnecessary?
Mar
6
comment Constraint containing 'max' in linear program unnecessary?
It would help to have it explicitly stated that each $load_j$ is nonnegative.
Mar
6
reviewed Close Python plotting a function
Mar
6
reviewed Approve Python plotting a function
Feb
27
awarded  Necromancer
Feb
26
comment Mathematica NIntegrate function in C++
I'm suggesting you spell out that I ntegral in order to get more specific advice on how best to write numerical integration routines.
Feb
25
comment Mathematica NIntegrate function in C++
We could be of greater assistance if state what exactly you want to integrate. "A challenging integral" might mean singularities, or a family with multiple parameters, or one where no closed form is available.