# All Questions

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### When semicoarsening is needed in multigrid method?

I am trying to understand multigrid in deep and all the coarsening techiques. So,assuming a 2D grid when semicoarsening is prefered instead of standard coarsening?What is the error's behaviour when a ...
34 views

### How suitable is multigrid method for time-dependent PDEs?

For elliptic PDEs (Poisson-type), the multigrid method is very sufficient, but how about time-dependent problems (i.e parabolic or hyperbolic PDEs)? Is it efficient to solve such problems using a ...
21 views

### Attempting to perturb ODE when initial condition is equilibrium point does not work

I have the following system of differential equations: $$x' = ax- cy + e1$$ $$y' = by- dx + e2$$ for variables $x,y$ and parameters $a,b,c,d,e1,e2$. I'd like to solve this in python, which is ...
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### Can we start Simplex method at a different corner than origin

I am working on a complex LP where I would like to get a fast heuristic solution and use it as a starting point for Simplex. The heuristic algorithm provides a corner point, but I am not sure how to ...
230 views

### Fast evaluation functions given by straight-line programs

I have a simple but long function that takes a vector x[10], and outputs a vector y[100]. It is an automatically generated eval function for a multivariate polynomial, ie, there is only (complex) ...