Computational Science Stack Exchange
Computational Science Stack Exchange

Most Popular

more tags
1500 questions
10
votes
1 answer

What does Static, Dynamic and Single Dynamic linking mean?

I use Intel MKL for BLAS and use the Intel MKL Link Line Advisor for help with the command line options. The advisor provides options for Static, Dynamic and Single Dynamic Library. What do these terms mean? There have been numerous posts on SO…
Inquest
  • 3,394
  • 3
  • 26
  • 44
10
votes
1 answer

Can a numerical scheme be used to determine the well-posedness of an initial or boundary value problem?

I know that we can use mathematical analysis techniques to prove if an IVP or BVP has a solution, is unique, and depends continuously on the boundary / initial values. For some PDE's, particularly non-linear pde's, it's very difficult, if not…
Paul
  • 12,045
  • 7
  • 56
  • 129
10
votes
2 answers

Trace An Isoline of an Expensive 2D Function

I have a problem similar in formulation to this post, with a few notable differences: What simple methods are there for adaptively sampling a 2D function? Like in that post: I have a $f(x,y)$ and evaluation of this function is somewhat expensive to…
meawoppl
  • 1,918
  • 11
  • 20
10
votes
2 answers

Safe application of iterative methods on diagonally dominant matrices

Suppose the following linear system is given $$Lx=c,\tag1$$ where $L$ is the weighted Laplacian known to be positive $semi-$definite with a one dimensional null space spanned by $1_n=(1,\dots,1)\in\mathbb{R}^n$, and the translation variance of…
usero
  • 1,663
  • 2
  • 14
  • 27
10
votes
2 answers

How is geometric programming different from convex programming?

How is (generalized) geometric programming different from general convex programming? A geometric program can be transformed into a convex program, and is typically solved by an interior point method. But what is the advantage over directly…
Thomas Klimpel
  • 2,141
  • 15
  • 35
10
votes
2 answers

Is the shooting method the only general numerical method for solving nonlinear boundary value ODEs?

During my wandering in Mathematica.se, I gradually noticed that a certain kind of differential equation solving problem is "troubling" us all the time, that is, the boundary value problem (BVP) of nonlinear ordinary differential equations (ODEs).…
xzczd
  • 348
  • 4
  • 20
10
votes
1 answer

Why do we have to rerun the CFD solver for higher Reynolds number?

I started to learn OpenFOAM from the Cavity tutorial which is provided at the web-site. When experimenting with different Reynolds numbers, in section "2.1.8.2 Running the code", tutorial says to rerun the solver because "It is sensible to increase…
danny_23
  • 501
  • 2
  • 7
10
votes
2 answers

Constructing explicit Runge Kutta methods of order 9 and higher

Some older books I've seen say that the minimum number of stages of an explicit Runge-Kutta method of a specified order is unknown for orders $\geq 9$. Is this still true? What libraries are there for automatically working with high order…
Kirill
  • 11,438
  • 2
  • 27
  • 51
10
votes
2 answers

Dictionaries in pseudocode

What is a good, common way to express dictionaries (= maps) in pseudocode? I.e. datastructures that basically allow to store values for keys, iterate over all key/value pairs, test for inclusion of a given key, etc. I have something like the…
Jan Pöschko
  • 203
  • 1
  • 2
  • 7
10
votes
2 answers

Selection of linear solver for GPGPU computation (OpenCL)

I have already developed a working solution of the Finite Element Method to solve heat transfer problems using GPU and OpenCL using the Conjugate Gradient method. The main disadvantage of this method is high demand for memory. Moreover, in case of…
Krzysztof Bzowski
  • 695
  • 4
  • 16
10
votes
3 answers

Matrix exponential of a real asymmetric matrix with Fortran 95 and LAPACK

I recently asked a question along the same lines for skew-Hermitian matrices. Inspired by the success of that question, and after banging my head against a wall for a couple of hours, I'm looking at the matrix exponential of real asymmetric…
qubyte
  • 491
  • 4
  • 15
10
votes
1 answer

Fortran 90/95: Deallocating variables

I understand the crucial importance of freeing memory when certain variables or arrays need to be reused later in the program, or may not be in use for a while. However, in my experience with scientific computing a lot of the code written is meant…
Salim
  • 165
  • 2
  • 8
10
votes
1 answer

How to assemble and solve a matrix system in parallel from values generated in different processors?

I am solving a multiscale problem using the Heterogeneous Multiscale Method (HMM). Essentially, my particular procedure uses the following iterative process: Solve many local matrix systems. Compute a value of interest from the solutions of the…
Paul
  • 12,045
  • 7
  • 56
  • 129
10
votes
3 answers

Is there a complexity between $O(n)$ and $O(n \log n)$

Is there a complexity degree that is bigger than $O(n)$ and smaller than $O(n \log n)$?
user3696586
  • 101
  • 3
10
votes
2 answers

Why is SQP better than Augmented Lagrangian for nonlinear programming?

In the technical report on Galahad[1], the authors state, in the context of general nonlinear programming problems, To our minds, there had never really been much doubt that SQP [sequential quadratic programming] methods would be more successful…
cjordan1
  • 805
  • 6
  • 16
1 2 3
…
99 100