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Instantaneous Growth Equation

Find a formula for y[x] if it is known that the instantaneous growth rate y'[x] is proportional to y[x] and it is known that y[0]=5 and y[5.7]=10. Does the value of y[x] double every 5.7 years? I ...
Bulldawg97's user avatar
0 votes
1 answer
53 views

Can Mathematica return the closed forms of 'arbitrary' function compositions?

I have only just downloaded Mathematica, so I am entirely new to this software. Here is what I am trying to do: If $f(x) = \frac{x}{2}$ is an example function, and $f^{(n)}(x)$ is the composition of $...
Wisdom Iwueze's user avatar
2 votes
2 answers
40 views

Reverse association and map through its values/keys

I suspect this could be done in a shorter and more readable code: Challenge: do it without Normal and Association. ...
azerbajdzan's user avatar
  • 15.1k
1 vote
0 answers
38 views

Problem with using RuleDelayed (:>)

I have defined a rule using rule delayed function as follows: innerWithDxU = (f1_ D[f2_[x,y],x]f3_[x,y] :>-f2 [x,y]D[f1 f3[x,y],x] ); ...
Rumayel Hassan Pallock's user avatar
4 votes
2 answers
58 views

How can I find values of m so that the function $\frac{-m+x^2+x-4}{4 x-m}$ increasing in the interval $(1,2)$?

I am trying to find value of marameters $m$ so that the function $f(x) = \dfrac{-m+x^2+x-4}{4 x-m}$ increasing in the interval $(1,2)$? I tried ...
John Paul Peter's user avatar
3 votes
4 answers
54 views

How to make expression-dependent replacements?

Consider as a toy example that I want a replacement which acts on {x,1,2,3} by replacing $x$ with the length of the list itself. In this example this should output ...
Adrien Martina's user avatar
3 votes
2 answers
58 views

FindRoot changes results from ParametricNDSolve

I solve numerically an equation, and I get the expected behaviour like the following graph But if I use FindRoot to get the roots before plotting, the plot of my ...
William Santos's user avatar
3 votes
1 answer
90 views

How to avoid circular refs in Language`ExpressionStore

Expressions are not garbage collected if there are references to them stored in the expression store. I use the following internal functions: ...
Kirill Belov's user avatar
-1 votes
0 answers
58 views

Strange plots by Mathematica [closed]

I think the picture speak for itself. Why is the x axis at y=1? Thanks
Vangsnes's user avatar
  • 591
4 votes
1 answer
110 views

3D FEM Memory Problem with Hexahedral Elements & V14 & Apple Silicon

After using MM V12 for a long time on a MacBook Pro 2011, which just lost 8GB or RAM from 16GB, I am trying V14 on a MacMini M2pro with 32GB. I had previously coded a coupled 3D EM problem involving a ...
Greenasnz's user avatar
  • 371
0 votes
2 answers
59 views

Generating lists where new elements depend on the previous element

I am interested in using some type of list or table in-built Mathematica function to generate a list, where the elements of the new list not only depends on the input values of a previously defined ...
John Doe's user avatar
  • 369
3 votes
2 answers
95 views

Calculating vertical displacement to intercept the perimeter of the circle after a horizontal shift

I can't come upon a solution for the question below. The background of the actual work is not interesting for the question, so l won't explain why I need the solution. I would be very thankful if ...
Darius E.'s user avatar
2 votes
0 answers
103 views

Is there a way to force 'Simplify' to use some assumptions?

First time poster. I have a basic question about 'Simplify'. I am encountering a problem when trying to simplify some algebraic expressions, where I find an unexpected behaviour of the 'Simplify' ...
Johnny Lemmon's user avatar
6 votes
5 answers
162 views

How to create sublists of a list based on the relation between their elements?

I have a large data set looking like this: ...
Delaram Nematollahi's user avatar
6 votes
5 answers
253 views

How to remove extra brackets from a list?

I have a list which looks like the following: list1={{{a,b,c},{a1,b1,c1},{an, bn,cn}},{{f,j,k},{f1,j1,k1},{fn, jn,kn}}} And I need it to be as follows: ...
Delaram Nematollahi's user avatar
2 votes
2 answers
50 views

DiscretizeRegion fails on a simple implicit region

No matter what option I set to DiscretizeRegion it fails on the region (missing second line). What else can be done? ...
azerbajdzan's user avatar
  • 15.1k
0 votes
0 answers
38 views

Assign the result to the lists [duplicate]

I am following the solution of the mixing eigenvalues from Carl Woll's answer in this post. In the end, the eigenvalues are plotted using this formula ...
blahblah's user avatar
3 votes
2 answers
132 views

How to draw a curve projection?

I want to draw the following projection picture for the cuspidal cubic curve in Mathematica. Does anybody know how to do this?
eloparti's user avatar
2 votes
3 answers
469 views

Why is Mathematica not simplifying eigenvalues?

For matrix A = {{x*Exp[I*y], z}, {z, x*Exp[(-I)*y]}}; , Mathematica yields the following eigenvalues: ...
Jee's user avatar
  • 294
3 votes
3 answers
163 views

Find maximum and minimum

I have been trying to find the max and minimum values and make it to a list. I have been using some of the previous forms and it doesn´t work.This is my function: ...
wijjoha24's user avatar
2 votes
2 answers
102 views

Conic sections: intersection of a plane and a cone. How can I change the equation of the plane to get conic sections automatically?

I tried to draw intersection of a plane and a cone. Hyperbola ...
minhthien_2016's user avatar
5 votes
4 answers
329 views

Still on Filling

I am really sorry to bother you for the same problems, but I cannot get in the view about this command, the filling option. What I want: to fill the semicircle part, under the $y = x$ curve. Here is ...
Enrico M.'s user avatar
  • 959
2 votes
0 answers
69 views

How to use GPT-4 vision?

How exactly do you call GPT vision, both programmatically and in chat-enabled notebooks? It seems like the image is being downsized when pasted inline, and it is unclear how many prior cells are in ...
M.R.'s user avatar
  • 31.4k
0 votes
0 answers
39 views

How to quickly sample points according to the given distribution?

Consider the following points sampler: ...
John Taylor's user avatar
  • 5,659
0 votes
1 answer
87 views

Numerical Fourier transform

I am having issues trying to numerically Fourier transform the following function \begin{equation} f(x) =\frac{1}{x^6}\sqrt{4m^2x^2+x^4}\log\biggm(\frac{2m^2 + x^2 + \sqrt{4m^2x^2+x^4}}{2m^2}\biggm) \...
MathZilla's user avatar
  • 123
0 votes
1 answer
138 views

How to solve this geometric problem with Mathematica?

I try to solve the following problem, making use of 14.0 on Windows 10 Let a triangle $\Delta$ (a contour with its interior) be chosen in the unit square $S$. To prove that the closure of the ...
user64494's user avatar
  • 26k
9 votes
5 answers
332 views

Reconstruct list from its PositionIndex

Is there a more elegant or shorter way of reconstructing a list from its PositionIndex? The following I regard quite cumbersome: ...
azerbajdzan's user avatar
  • 15.1k
2 votes
2 answers
104 views

How to get angles along a line?

What is the best way to get the angles along a line? I have tried this for example: ...
flinty's user avatar
  • 25.1k
0 votes
1 answer
54 views

Understanding the example of sensitivity analysis in Documentation using ParametricNDSolve

There is an example in Documentation for studying sensitivity analysis, using ParametricNDSolve: ...
A novice's user avatar
  • 405
0 votes
0 answers
39 views

Why does NSolve does not give solution what Solve does [closed]

I have 47 set of linear system of equations. The Solve command is giving the answer, but NSolve is unable to return answers. The parameter values are same in both cases. If I calculate the values ...
Tasawar Iqbal's user avatar
4 votes
1 answer
184 views

Fourier Transform of 2D data using Fourier

I don't understand the documentation of Fourier. My goal is the get the coefficients of the Fourier-series (i.e. $\sum_{n\in \mathbb{Z}} c_{n,m} e^{inx+imy}$) of ...
Confuse-ray30's user avatar
6 votes
1 answer
167 views

How to get properties from a Polygon object?

We can get polygons by this code: polys = (SeedRandom[#]; Polygon[RandomInteger[20, {4, 2}]]) & /@ Range[6] How to get those properties? When I dig ...
yode's user avatar
  • 26.7k
0 votes
0 answers
39 views

Dimensionality problem with initial conditions [closed]

I am trying to solve these two systems of equations with NDSolve, however I am getting a problem I do not know how to fix. The code is as follows: ...
Jules Alvarez's user avatar
0 votes
1 answer
85 views

Solving a 3+1D Wave Equation

I am having some problems with finding the solution to the magnetic field, B[x,y,z,t]. Is there anything I can change to my code to obtain a solution of B[x,y,z,t] with the initial conditions and ...
Tommy Wong's user avatar
1 vote
0 answers
43 views

How to get a single line title in a Manipulate box? [closed]

I'm having a text output issue with the following code: ...
Cham's user avatar
  • 4,093
1 vote
0 answers
49 views

Why I can't install this package [closed]

I am trying to run C++ in Mathematica. I got a package "LTemplate" from the answer from Szabolcs in this post: How to simplify writing LibraryLink code?. However I can't install it. This is ...
xpaul's user avatar
  • 261
3 votes
4 answers
162 views

Sort Column as a Row

I have a = {1, 2, 3, 10}; b= {2, 3, 4, 8}; t= Do[If[a[[i]]+b[[i]]>3,Print[a[[i]]],"No"],{i,1,4}]; 2 3 10 I need to get the result; t={2,3,10}
Alyasaa Jasim's user avatar
3 votes
2 answers
200 views

Plotting a special 2d set in Mathematica

I have a set $S$ in $\mathbb{R}^{2}$ with the following description: $$ S=\{x\in\mathbb{R}^{2}\mid0\leq x^{\top}y\leq1,\;\forall y\in S\}. $$ In other words, if $x$ and $y$ are points in $S$, then we ...
TDH's user avatar
  • 489
1 vote
1 answer
65 views

How combine two DensityPlot3D in only one graph

I need to combine two DensityPlot3D in only one graph but the "Show" doesn't work for that. ...
Rubens Filho's user avatar
0 votes
1 answer
51 views

HypExp package throwing errors when loading

I am trying to load the package HypExp by using the instructions given on the site. The package throws an error ...
QFTheorist's user avatar
6 votes
1 answer
213 views
+500

Visualizing diagrams needed to compute $\operatorname{Tr}(A^3 (A^T)^3)$

I'm looking for help getting Mathematica code to construct diagrammatic expressions like the following, obtained by River Li as a way to compute $\operatorname{Tr}(A^2 (A^T)^2)$ for $d\times d$ matrix ...
Yaroslav Bulatov's user avatar
3 votes
0 answers
31 views

Mathematica call CompiledFunction from Python with Listable and Parrallelization attributes

I have a CompiledFunction e.g. this: ...
Okarin's user avatar
  • 31
2 votes
0 answers
34 views

Take symbolic derivative of summation expression and display as unexpanded sum

My main problem here is two-fold: Take symbolic derivative of summation expression Stop summations from being "unrolled"/expanded, e.g., displayed as the sum of terms I also have some ...
ImagineBaggins's user avatar
0 votes
1 answer
57 views

Clear Guidelines for Symbolic Calculation With Units?

The following notebook performs a relatively simple physical calculation interacting position, velocity and acceleration of two charged point particles according to Weber electrodynamics.It is simple ...
James Bowery's user avatar
4 votes
1 answer
107 views

Is the WolframScript error message "The product exited because of a license error" accurate?

I find that sometimes when I use wolframscript to run a .wls file (as part of a workflow involving hundreds of such files), its ...
Ed Bennett's user avatar
0 votes
1 answer
55 views

Generate all commutators and anti-commutators up to a certain order of a list of matrices

I am given a list of matrices. At first order I want to evaluate the commutators and anti-commutators of all pairs in the list and return a new list that contains two lists: one containing all ...
JohnnyB's user avatar
  • 93
0 votes
0 answers
34 views

NDSolve and GeomagneticModelData [closed]

I am trying to use GeomagneticModelData in NDSolve. My code is long and complicated, but here is an artificial example that illustrates my question: ...
Peter Fisher's user avatar
0 votes
1 answer
78 views

Plot a surface between three intersecting curves using 3D data sets

I would like to plot a surface between the intersecting points of three 3-dimensional curves. The curves are created using ListLinePlot3D, from the following lists: List1: ...
Ryan Lobjoit's user avatar
3 votes
0 answers
73 views

Crumpling up a line: how to tell if a Line self intersects?

I'm crumpling up lines by rotating them at random positions. That is I take a line, a random rotation angle, and a random pivot point, then every point beyond that gets rotated about the pivot by the ...
flinty's user avatar
  • 25.1k
1 vote
0 answers
59 views

(N)Solve does not solve a linear system of $2l+1$ variables for $l\geq17$

(MMA v. 14.0, and 13.0) This is a strange behaviour I encountered when trying to determine Fourier coefficients in the most naive way: ...
Confuse-ray30's user avatar

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