# All Questions

7,609 questions
47 views

### Combining multiple coupled 1st order equations in python

I'm having serious troubles with solving translating 3 coupled differential equations into python. The 3 DE's stem from a 4th order DE used to calculate the bending moment of an underwater pipeline ...
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61 views

### Load the mesh file with boundary marks

I'm want to load a mesh from a file, generated by triangle, and I want to use the boundary marks of its nodes (boundary marks of the file). It is possible? Also, I can change the mesh generator (or ...
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### Eigenvectors associated to two quasi-degenerate eigenvalues

I need to find the smallest eigenvalue and the corresponding eigenvector of a sparse matrix $M$ whose dimension is $\approx 10^4$. Within Matlab enviroment, I use the command ...
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### Asymptotic Complexity of Gaussian Elimination using Complete Pivoting

I would like to know the algorithm asymptotic complexity with Complete Pivoting. With partial pivoting, it is known to be $O(n^3)$. Is it the same for complete pivoting?
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### SDE solver in python: manual determination of integrator step size (dt)

Aim: I am trying to solve a system of SDEs, while using the SDEint package in python 3.x. It is a system of SDEs adapted from and inspired by the Zombie Apocalypse ...
I'm trying to calculate total energy of a system $$E(v, h) = -\sum a_iv_i - \sum b_jh_j - \sum_{i,j} v_ih_jw_{ij}$$ Python equivalent looks like this ...
I would like to solve system $Ax=b$, where $A$ is SPD, but very ill-conditioned ($\text{cond}(A)>10^{11}$). I am interested in using UNpreconditioned version of the conjugate gradient method. Is ...