# All Questions

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### Adjoint method for optimization problem

I am interested in the adjoint method for shape optimization problems. However, I couldn't find a helpful introduction. So I come here and look forward to some enlightening advices. Could you direct ...
2k views

### When should I use C++ expression templates in computational science, and when should I *not* use them?

Suppose that I'm working on a scientific code in C++. In a recent discussion with a colleague, it was argued that expression templates could be a really bad thing, potentially making software ...
2k views

340 views

### What is a good introduction to graph theory / algorithm

By good I mean minimal and essential. One whose concepts form a minimum spanning tree, and whose words are precious :) (A small pdf would be perfect)
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### Is there a tool out there that can generate interval extensions of Fortran (or C) functions by parsing Fortran (or C) code?

Case studies in my PhD thesis require that I have interval extensions of Fortran subroutines in CHEMKIN-II (apologies for the link; it's the best one I could find for a package no longer distributed ...
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### Standard format for finite element meshes

Does there exist a standard format for finite element meshes which is widely used in the industry? Thanks!
141 views

### Compability conditions in domain decomposition methods

Suppose we want to solve the Poisson equation $\Delta u = f$ on a domain $\Omega$ with Dirichlet boundary conditions. One possible way to do is by a domain decomposition method. There is a condition ...
583 views

### On Vanilla Preconditioners for solving dense $Ax=b$ iteratively

I am looking for preconditioners which don't assume anything about the matrix or its origins. I basically want to be able to type in the following in MATLAB and have quick solving time: ...
223 views

### Determining the algorithmic complexity

A few of the iterative matrix algorithms (CG,GMRES etc.) I have authored are acting rather funny. They converge to the right answers but take abnormally long time to run. I am in the process of ...
991 views

### Which iterative linear solvers converge for positive semidefinite matrices?

I want to know which of the classic linear solvers (e.g Gauss-Seidel, Jacobi, SOR) are guaranteed to converge for the problem $Ax=b$ where $A$ is positive semi definite and of course $b \in im(A)$ (...
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### Fast algorithms to find the eigenvalues of some matrix on intervals of interest

I am curious how to quickly compute the eigenvalues for arbitrary matrices, sparse or dense, restricted on some given interval of interest. Suppose we have an arbitrary $n\times n$ matrix $A$, ...
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### Sort a cloud of points with respect to an unstructured mesh of hexahedral cells

Question How would you sort a cloud of points with respect to an unstructured mesh of hexahedral cells? Each cell has a centre and a unique label to represent it. There are two cloud points ...
2k views

### 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....