6.2.1 Top new questions this week

6.2.1.1 Adding Regularisation to Built-in Interpolation function

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218764

tl;tr;  How to improve performance of regularised Interpolation? 
 
Context 
 
Since Version 12, Mathematica now incorporates a range of (underrated IMHO) regularisation methods to Fit and FindFit. 
 
 
 
... 
[performance-tuning] [fitting] [interpolation]
 

asked by chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1089 17 votes

answered by chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1089 7 votes

6.2.1.2 How to model diffusion through a membrane?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218983

This is a follow-up on How to handle discontinuity in diffusion coefficient? 
 
Consider diffusion of $u(t,x)$ on the domain $x \in [0,2]$ with some simple boundary conditions such as $u(0) = 2, u(2) =  ... 
[differential-equations] [numerics] [finite-element-method] [discontinuity] [heat-transfer-equation]
 

asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 13 votes

answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 7 votes

6.2.1.3 How to draw a "proper" tree diagram

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218859

TreePlot[{ 
{0 -> "Mr 1", 1/10}, 
{0 -> "Mr 2", 2/10}, 
{0 -> "Mr 3", 3/10}, 
{0 -> "Mr 4", 4/10}, 
{"Mr 1" -> "A1",  2/10 }, 
{"Mr 1" -> "B1",  1/10 }, 
{"Mr 1"  ... 
[graphics] [output-formatting] [trees]
 

asked by CasperYC https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62701 13 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 18 votes

6.2.1.4 How can I list all tech note pages?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219033

It seems since v12.1 a new doc type, tech note, is included in the documentation. 
 
However, I cannot find an index page for the tech notes. 
So how can I list all such tech note pages? 
 
[documentation]
 

asked by sunt05 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=260 10 votes

answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 11 votes

6.2.1.5 Generating long binary lists fast?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219115

Given list $L$ consisting only of $0$'s and $1$'s, we read $L$ backwards and construct a new list $O$ such that: (we start with $O=\{1\}$ and then apply the two rules:) 
 
 
if we encounter $n$  ... 
[list-manipulation] [performance-tuning]
 

asked by Vepir https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49840 9 votes

answered by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 5 votes

6.2.1.6 Control grain size of stipple shading

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219020

Mathematica 12.1 introduced a number of amazing shaders such as StippleShading. 
 
Is there a way to control the grain size of StippleShading? 
 
On a standard resolution screen it looks like this: 
 
 
 
On  ... 
[graphics3d] [output-formatting] [style] [rasterize] [publishing]
 

asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 9 votes

6.2.1.7 Extracting COVID AdministrativeDivision data from Wolfram Resource

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218833

Wolfram makes the COVID-19 case data available in a form that is conveniently formatted for processing in  Mathematica. 
 
It can be accessed using: 
 
data2 = ResourceData[ResourceUpdate["Epidemic Data  ... 
[resource]
 

asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 9 votes

answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 7 votes