8.42.2 Greatest hits from previous weeks

8.42.2.1 Skip header lines on import

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718

When importing a data file what are the comment symbols for Mathematica? 
That is, given a file like this 
 
 blabla 
bulbul 
 
1 2 6 54 7 ... 
.. 
 
 
what symbol do I have ... 
[import] [text]
 

asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 Score of 21

answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 Score of 18

8.42.2.2 Calculating the normalization constant for a wavefunction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=99248

How can I compute the normalization constant for a quantum mechanics wave-function, like $\Psi(x) = N \exp(-\lambda x^2/2)$ by using Mathematica? (The normalization constant is $N$). 
[physics]
 

asked by infiniteNOP https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35524 Score of 2

answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 Score of 5

8.42.2.3 How to add a front-end to the free Wolfram Engine?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=198839

https://blog.stephenwolfram.com/2019/05/launching-today-free-wolfram-engine-for-developers/ 
 
http://www.wolfram.com/engine/ 
 
The Free Wolfram Engine for Developers is available for pre-production ... 
[front-end] [free-wolfram-engine] [jupyter-notebook]
 

asked by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 Score of 79

answered by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 Score of 64

8.42.2.4 Finding Limits in several variables

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544

Is there a way to find a limit of a multivariable function, like 
 
$$\lim_{(x,y)\to (0,0)} f(x,y)$$ 
with Mathematica? 
 
When $f$ is continuous, we can use 
$$\lim_{(x,y)\to (0,0)} f(x,y)=\lim_{(x,0)\... 
[functions] [calculus-and-analysis]
 

asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 Score of 33

answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 Score of 42

8.42.2.5 Why round to even integers?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116

According to the Mathematica help: 
Round rounds numbers of the form x.5 toward the nearest even integer. 
For example: 
 
 Round[{0.5, 1.5, 2.5, 3.5, 4.5}] 
 
 
gives 
... 
[numerics] [language-design]
 

asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 Score of 84

answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 Score of 52

8.42.2.6 How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave.  I have written code that works, but it does not "shade" the area between the graph and the axes.  Both the ... 
[graphics] [physics] [visualization]
 

asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 Score of 23

answered by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 17

8.42.2.7 How to find the position of elements in a list satisfying criteria

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180

Say I have a list  x={2,4,6,8,10}  and I want to find out the positions of the elements that are greater than 7. 
 
... 
[list-manipulation]
 

asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 Score of 72

answered by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 70