7.25.1 Top new questions this week

7.25.1.1 How to straighten a curve?
7.25.1.2 Hello world for FunctionCompile with Images?
7.25.1.3 How to compute eigenvalues of linear function (not matrix)?
7.25.1.4 Applying functions to list elements selectively
7.25.1.5 How to use Intersection[] but keep the original list order
7.25.1.6 Why does Longest not work on OptionsPattern?
7.25.1.7 "graph-paper" style for z=0 plane in a 3D plot
7.25.1.1 How to straighten a curve?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251570

What's the easiest way to get the following animation for a given parabola where the arc length is preserved (that is, for two points in the parabola, I straighten it as follows) 
 
My main goal is the ... 
[plotting] [functions] [function-construction] [geometry]
 
asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 10 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes
7.25.1.2 Hello world for FunctionCompile with Images?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251395

I'm looking for some good examples of FunctionCompile applied to image processing code since there doesn't seem to be anything on this in the documentation. So here's a first attempt at a hello world ... 
[image-processing] [image] [compile] [function-compile]
 
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 9 votes
7.25.1.3 How to compute eigenvalues of linear function (not matrix)?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251508

How to compute eigenvalues of a known linear function? 
In Julia, there is a packagehttps://jutho.github.io/LinearMaps.jl/dev/ to compute the matrix representation of given function, then we can ... 
[linear-algebra] [eigenvalues]
 
asked by swish47 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80512 7 votes
7.25.1.4 Applying functions to list elements selectively

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251520

I've got two lists that contain an element identifier and a number: 
... 
[list-manipulation]
 
asked by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 6 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 4 votes
7.25.1.5 How to use Intersection[] but keep the original list order

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251531

I want to keep the original order of l1: 
... 
[list-manipulation] [programming] [sorting]
 
asked by Matvei Kruglyak https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75443 6 votes
answered by Matvei Kruglyak https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75443 7 votes
7.25.1.6 Why does Longest not work on OptionsPattern?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251367

When having a function with optional arguments and options, I frequently find myself writing something like this: 
... 
[function-construction] [pattern-matching] [options] [argument-patterns] [optional-arguments]
 
asked by Lukas Lang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36508 6 votes
7.25.1.7 "graph-paper" style for z=0 plane in a 3D plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=251443

I'm looking to get publication-quality illustrations in the style of "Interactive Linear Algebra" book where z=0 plane has the look of graph-paper 
 
What is a good pattern to achieve this ... 
[graphics3d] [visualization]
 
asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 5 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 8 votes