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Patrick Sanan
  • Member for 9 years, 5 months
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50 votes
4 answers
27k views

What makes Fortran fast?

  • 877
40 votes
4 answers
33k views

How does the MATLAB backslash operator solve $Ax=b$ for square matrices?

  • 3,334
33 votes
9 answers
5k views

Modern resources for learning FEM

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28 votes
5 answers
5k views

Are there any famous problems/algorithms in scientific computing that cannot be sped up by parallelisation

  • 487
28 votes
2 answers
14k views

Why is my iterative linear solver not converging?

  • 25.3k
21 votes
2 answers
14k views

What is pseudo time-stepping?

18 votes
4 answers
5k views

Portable multicore/NUMA memory allocation/initialization best practices

  • 25.3k
18 votes
5 answers
3k views

What is the advantage of multigrid over domain decomposition preconditioners, and vice versa?

17 votes
1 answer
2k views

Can a Krylov subspace method be used as a smoother for multigrid?

  • 11.8k
15 votes
1 answer
769 views

What is the current state of polynomial preconditioners?

  • 3,500
14 votes
1 answer
1k views

How is Krylov-accelerated Multigrid (using MG as a preconditioner) motivated?

14 votes
2 answers
1k views

Impose the compatibility conditions for mixed finite elements method in Stokes equation

  • 2,532
12 votes
1 answer
1k views

Smallest eigenvalue without inverse

11 votes
1 answer
4k views

Raviart-Thomas elements on reference square

11 votes
2 answers
3k views

Understanding the cost of adjoint method for pde-constrained optimization

  • 11.8k
10 votes
3 answers
3k views

How to construct a prolongation and restriction operator for an algebraic multigrid solver?

  • 11.8k
9 votes
1 answer
355 views

Iterative "solver" for $x^t \Sigma^{-1} x$

  • 261
8 votes
2 answers
1k views

How does a Sparse Direct Solver know about dimensionality of a problem being solved?

  • 1,101
8 votes
1 answer
972 views

MPI policy for multiple asynchronous transfers

  • 3,048
5 votes
1 answer
272 views

Is PETSc's DMDA relying on undefined behavior?

  • 153
4 votes
1 answer
655 views

$L^2$-error in FEM: how to compute integral over reference element?

3 votes
1 answer
847 views

Numerical integration with singularities