Top new questions this week

11.21.1 Top new questions this week

11.21.1.1 Structured mesh for a rectangle with two holes inside
11.21.1.2 Efficient calculation of treewidth
11.21.1.3 Could not generate mesh when the mesh count is too large
11.21.1.4 Adding multiple equations
11.21.1.5

Implementing DC Decomposition of Nonconvex Polynomials Using Algebraic Techniques (Hall's Formulation 5.6) in Mathematica?

11.21.1.6 Wave equation via Laplace transform
11.21.1.7 Why are these two cuboids rendering differently?

11.21.1.1 `Structured mesh for a rectangle with two holes inside`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314068

I would like to use the FEMAddOns package to make a structured mesh (with quad elements with  InterpolationOrder -> 2, "MeshOrder" -> 2  ) with two ... 
[finite-element-method] [mesh]

asked by Carlos Henrique Daros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=110745 Score of 7

answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 Score of 6

11.21.1.2 `Efficient calculation of treewidth`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314074

The treewidth of an undirected graph is a very important concept in graph theory. 
 
I have ported the python code from a related Code Golf question  to Mathematica, and it has passed the test cases. 
... 
[performance-tuning] [graphs-and-networks]

asked by Ahamad https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106668 Score of 4

answered by Ahamad https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106668 Score of 4

11.21.1.3 `Could not generate mesh when the mesh count is too large`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314146

I am trying to generate 1D mesh points on x axis, shown below: 
... 
[finite-element-method] [mesh]

asked by Johnson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=85242 Score of 3

11.21.1.4 `Adding multiple equations`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314124

My goal is to add three equations: a==b, c==d, e==f. I could used MapThread and Replace as shown below, but is there a simpler method? 
... 
[equation] [addside]

asked by Soon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=78050 Score of 3

answered by Bill Watts https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53121 Score of 3

11.21.1.5 `Implementing DC Decomposition of Nonconvex Polynomials Using Algebraic Techniques (Hall's Formulation 5.6) in Mathematica?`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314134

I'm working on implementing a difference-of-convex (DC) decomposition for nonconvex polynomials, following the algebraic approach described in Georgina Hall's thesis "Optimization over ... 
[mathematical-optimization] [algorithm]

asked by Tuong Nguyen Minh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69278 Score of 3

11.21.1.6 `Wave equation via Laplace transform`

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=314109

Solve, via Laplace transforms 
\begin{align} 
w_{tt}&=w_{xx}\\ 
w(0,t)&=g(t), \lim_{x \rightarrow \infty}w(x,t)=0, \: x,t\geq 0\\ 
w(x,0)&=0=w_t(x,0) 
\end{align} 
where $w$ is the ... 
[differential-equations] [equation-solving] [symbolic] [integral-transforms] [boundary-condition-at-infinity]