1.3 Thursday, May 13, 2021

1.3.1 Top new questions this week
1.3.2 Greatest hits from previous weeks
1.3.3 Can you answer these questions?

1.3.1 Top new questions this week

Finding "chains" of numbers in a matrix
How to formulate this problem in Mathematica?
Problem with optimal control and Pontryagin’s maximum principle
Sorting Associations by DayName (day of week) using KeySort and/or KeySortBy
Using the PowerPoint’s laser pointer in symbols of plots
How would one add Hyperreals as a new type to Mathematica?
Extract held value from Association

Finding "chains" of numbers in a matrix

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245937

To give some context, this problem is related to music theory. I have a matrix I’m generating with this code:

asked by Eriek https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18649 6 votes

answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 9 votes

How to formulate this problem in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245908

Say, I have the following expressions

f = R[p] 
g = S[p]

where R,S are rational functions, and I want to find a polynomial such that

asked by nilo de roock https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=156 6 votes

answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 11 votes

Problem with optimal control and Pontryagin’s maximum principle

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245797

For dynamic system: \(\dot {x}=\frac {df}{dx}+u\) where \(f=e^{-x^2}\) It is necessary to develop optimal control, minimizing criterion: \(J= \int _{0}^{t_f} ((\frac {df}{dx})^2+u^2) \,dt \) Algorithm:

We ...

asked by dtn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67019 6 votes

answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 7 votes

Sorting Associations by DayName (day of week) using KeySort and/or KeySortBy

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245721

I have an association where the keys are the days of the week:

asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 6 votes

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

Using the PowerPoint’s laser pointer in symbols of plots

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245800

I am interested in exploiting a symbol that is similar to the PowerPoint’s laser pointer in the role of PlotMarkers. Is there any idea to create that!? This symbol ...

asked by Inzo Babaria https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=33967 5 votes

answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes

How would one add Hyperreals as a new type to Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245782

Hyperreals are an extension to the real numbers; they formalise the concepts of infinities and infinitestimals as numbers, rather than the named limit points outside of the system of reals and form ...

asked by Julian Moore https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12858 5 votes

Extract held value from Association

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245784

Consider an association which contains a key which must not be prematurely evaluated. assoc = <| key :> value |>

For example, a value of ...

asked by Anti Earth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=32591 5 votes

answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 6 votes

1.3.2 Greatest hits from previous weeks

1 Plot, 2 Scale/Axis
How to perform a multi-peak fitting?
Standard deck of 52 playing cards in curated data?
Is it possible to export the equations from Mathematica to MATLAB?
LaTeXand Mathematica
How can I plot implicit equations?
Calling Correct Function for Plotting DiracDelta

1 Plot, 2 Scale/Axis

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627

I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?

I found the following on the help menu but quite ...

asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 152 votes

answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 152 votes

How to perform a multi-peak fitting?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336

I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3). The ...

asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes

answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes

Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?

If not, is there a way ...

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes

Is it possible to export the equations from Mathematica to MATLAB?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035

Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?

asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 43 votes

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes

LaTeXand Mathematica

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736

I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems

I would ...

asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 130 votes

answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 46 votes

How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram | Alpha, you get nice graphs:

graph 4 x^4 + y^2 = 2

How do you do this in Mathmatica? I realize that these are not ...

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 40 votes

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 41 votes

Calling Correct Function for Plotting DiracDelta

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506

I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...

asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes

answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes

1.3.3 Can you answer these questions?

Excess lines in the solution plot of vector ODE
Algorithmically imposing a substitution in a difficult integral
How to expand a rational function as a single fraction

Excess lines in the solution plot of vector ODE

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245826

I’ve got an ODE system, which I attempt to solve by two ways: solving the system itself, and using vector ODE. Here is code of first way:

asked by Cpp Nosavvier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79893 3 votes

Algorithmically imposing a substitution in a difficult integral

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245884

Consider the following integral: \[ I = \frac {1}{\pi c^2} \int \limits _{r=0}^c 2 \pi r\ e^{-\frac { \left ( \sqrt {a^2 - r^2} -\sqrt {b^2 - r^2} \right )}{\lambda }}\ dr \] under the conditions \(a>b>c>\)...

asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 2 votes

How to expand a rational function as a single fraction

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245673

This has been annoying me for a long time. I want a rational function to be represented in the form \[\frac {a_nx^n+....a_0x^0}{b_mx^m+....b_0x^0}\] But this seems to be quite difficult. Mathematica ...

asked by grdgfgr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=28163 2 votes

answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 0 votes