Top new questions this week:
|
|
Consider the following expression: $$f(t) = B+\sum_{k=1}^{N} A_k\cos(\omega_kt)$$ where $A$ and $B$ are known. the frequencies are also known but are not multiples of a fundamental frequency. However, …
|
|
The signed volume of the triangle formed by the points $p, q, r$ in the plane is defined to be $$\text{volume}(p, q, r) \equiv \det\left[\begin{matrix}q_1 – p_1 & r_1 – p_1 \\ q_2 – p_2 & r_2 -…
|
|
I have two values $a$ and $b$ where $a \ge 0$ and $b \ge 0$ and I have to calculate the formula below. $$ \frac{1}{2}\int_0^1\text{abs}\left[\left( \frac{p_i^{(a – 1)} \times (1 – p_i)^{(b – 1)}}{\…
|
|
I have a problem where I heavily need to restrict the number of points at which I sample a function based on the values of a different function. I have two functions: $f:{\mathbb{R}\times [0,\infty)\…
|
|
I am solving a 1D diffusion-type equation with the finite-difference Crank-Nicolson (CN) scheme, and I need to densify the spatial grid around the central point. One could change the spatial variable …
|
|
I’m trying to do FEM for a very basic version of the linear full Stokes equations in two dimensions. Say we are working in the grid $[0,1]\times[0,1]$ in the $xy-$plane. To solve an FEM problem for a …
|
|
the equation is $$ \left\{\begin{array}{l} -\nabla \cdot \mathbb{T}(\mathbf{u}, p)=\mathbf{f} \text { in } \Omega, \\ \nabla \cdot \mathbf{u}=0 \text { in } \Omega, \\ \mathbf{u}=\mathbf{g} \text { on …
|
Greatest hits from previous weeks:
|
|
I asked this question to help me understand what is going on in one of Maxwell’s equations. I am happy with following through the maths on paper now, but would like to use MATLAB to take it one step …
|
|
Suppose $$\begin{align*} \min A &\mathrm{vec}(U) \\ &\text{subject to } U_{i,j} \leq \max\{U_{i,k}, U_{k,j}\}, \quad i,j,k = 1, \ldots, n \end{align*}$$ where $U$ is a symmetric $n\times …
|
|
I have several challenging non-convex global optimization problems to solve. Currently I use MATLAB’s Optimization Toolbox (specifically, fmincon() with algorithm=<...
|
|
While reading some literature on PDE solvers I came across the term pseudo time-stepping today. It seems to be a common term, however I failed to find a good definition or an introductionary article …
|
|
I would like to determine the theoretical number of FLOPs (Floating Point Operations) that my computer can do. Can someone please help me with this. (I would like to compare my computer to some …
|
|
Following from my previous question I am trying to apply boundary conditions to this non-uniform finite volume mesh, I would like to apply a Robin type boundary condition to the l.h.s. of the domain (…
|
|
Are there any tools in Python that are like Matlab’s parfor? I found this thread, but it’s four years old. I thought maybe someone here might have more recent experience. Here’s an example of the …
|
Can you answer this question?
|
|
I have a nonlinear 2nd order boundary value differential equation where I used finite-difference method (central finite-difference) to solve it. $$z”(x)-\frac{\frac{1}{100} z(x)^4 \left(2 z'(x)^2+12\…
|
