11.15.3 Can you answer these questions?

11.15.3.1 Why is RSquared Missing[] in FittedModel produced by LinearModelFit

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=312434

I have been doing some automated data processing that uses both a projection from a FittedModel and the RSquared value. I find for some of the data, the RSquared value given as a model property is ... 
[probability-or-statistics]
 

asked by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 Score of 3

11.15.3.2 How to change default precision for ALL variables and computations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=312364

I struggled a lot to make a piece of code working. IN the end, it was all about changing all numbers to have high precision, for example I changed 
... 
[precision-and-accuracy] [machine-precision]
 

asked by user3410765 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=101547 Score of 2

11.15.3.3 How to calculate Kazhdan-Lusztig Polynomials of Coxeter groups using Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=312410

How to calculate Kazhdan-Lusztig Polynomials using Mathematica? 
References: 
 
TABLES OF KAZHDAN-LUSZTIG POLYNOMIALS 
Kazhdan-Lusztig Polynomials - Combinatorics 
kazhdan-Lusztig-polynomial-calculator (of ... 
[polynomials] [combinatorics] [algebra]
 

asked by Ahamad https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106668 Score of 1