7.28.1 Top new questions this week

7.28.1.1 Why does FunctionPeriod give two different results for alternative forms of the given function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253386

I have a function for the variable $x>0$ and constant $a\in\mathbb{R}$. I write it in its two alternative forms 
$$f(x)=\cos a\pi-\cos x\pi =-2\sin\frac{(a-x)\pi}{2}\sin\frac{(a+x)\pi}{2} $$ 
Then, I ... 
[trigonometry] [periodic-function]
 

asked by Phys96 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76936 7 votes

answered by Somos https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61616 4 votes

7.28.1.2 Why is Evaluate not handle on the Association?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253280

This is a demo code 
... 
[evaluation]
 

asked by partida https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15961 6 votes

answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 3 votes

7.28.1.3 FindFit problem in "Debye temperature" fitting

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253361

I am fitting the Debye temperature using FindFit, here is my code: 
... 
[fitting]
 

asked by user58177 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58177 6 votes

answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 9 votes

7.28.1.4 Animating Curl noise applied to an image

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253252

I'm trying to produce turbulent swirling effects in an image using Curl Noise. The idea is you start off with some random field (usually Perlin noise) and use the curl of this field to displace the ... 
[image-processing] [animation]
 

asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 5 votes

answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 0 votes

7.28.1.5 How to efficiently build a large sparse matrix and overloading a compiled function?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253557

I would like to construct a large sparse matrix folding from rank-4 tensor given by the following: 
$\mathcal{L}_{1L}^{00}(i,j)=\mathcal{L}_{1L}^{00}(m_1,m_2;M_1,M_2)$ 
The indices of matrix $(i,j)$ are ... 
[matrix] [performance-tuning] [compile] [sparse-arrays] [function-compile]
 

asked by Bob Lin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59705 4 votes

7.28.1.6 Is there any simpler way to generate dominoes?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253432

I want to make a list of dominoes. My attempt is as follows. 
 Subsets[#, {2}]~Join~Thread[{#, #}] &@Range[0, 6] 
 
 
{{0,1},{0,2},{0,3},{0,4},{0,5},{0,6},{1,2},{1,3}... 
[list-manipulation]
 

asked by Who Save Me Save Entire Worldhttps://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 4 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes

7.28.1.7 Find the longest sequence of "1" in a SubList

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=253277

I'm trying to return the sublist(s) with the longest sequence of 1, although my code is working in a majority of cases, there are exceptions that I don't understand . 
Example: 
... 
[list-manipulation] [sequence]
 

asked by Yassin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80988 4 votes

answered by Coolwater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9754 8 votes