All Questions
88,790
questions
0
votes
0
answers
7
views
Purple color text related with RowBox
Type the first line of following code and press enter key.
...
- 3,529
0
votes
0
answers
10
views
0
votes
0
answers
28
views
Problem with bifurcation diagram for driven damped pendulum
I am using the following equation of motion for a driven damped pendulum:
$$\frac{d^2\theta}{dt^2} = -\frac{g}{l}\sin \theta -\gamma \frac{d\theta}{dt} + A\sin(\omega_d t)$$
where $\theta$ is the ...
- 689
2
votes
0
answers
15
views
Is it possible to prevent the very first evaluation of Dynamic when it appears on screen?
Is it possible to tell DynamicBox to not run its very first dynamic evaluation when it appears on screen, and instead, to just show its ...
- 19.3k
0
votes
2
answers
48
views
1
vote
1
answer
47
views
Difficulty to Solve the Generalized Wave Equation
Given the following problem
$$u_{tt}-\frac{v}{2}\cdot u_{xx}+\frac{v}{2}\cdot x^2 \cdot u(x)=0 $$
$$u(x,0)=f(x)$$
$$u_t(x,0)=g(x)=0$$
Where $ f(x)=y_0(x) $
$y_n$ are the Eigenfunctions that defined ...
0
votes
1
answer
33
views
Properly Format Vertical Bar with Supersubscript
I'm having trouble emulating the following (extra long) vertical bar format in a text cell:
The closest I could get to in a text cell is:
which doesn't look great; it's underlying code is
...
- 5,221
0
votes
0
answers
24
views
Flat Group Delay of a Transfer Function, Units? [closed]
I'm trying to find a flat Group Delay (tg) of a Transfer Function [H(s)] and having trouble with units. The filter has a given Group Delay (tx) that needs to be balanced with this filter's tg. The ...
2
votes
1
answer
74
views
Apply ReplaceAll to a whole notebook
I'm an avid tauist (tauday.com) and I don't like the fact that Mathematica displays equations with $\pi$ instead of $\tau=2\pi$. I know that I can "force" it to display $\tau$ by e.g.
...
- 135
1
vote
1
answer
65
views
How to express the argument through the function?
I would like to express argument $d$ through $f$ and $B$ and to get $d(f,B)$
$$f(d,B)=B\left(\left(\frac{1}{4}-\frac{d}{B}\right)\left( 1-\left(1- e^{-30d/B} \right)^8\right)+\frac{2/B}{3+1/B^2}\left(...
- 781
1
vote
0
answers
23
views
Invalid PeriodicBoundaryCondition for Navier Stokes problem using NDSolveValue
Background: I'm looking to have a 2D re-entrant channel of a geophysical flow that is forced by a wind stress at the surface ("taux"; below) and experiences planetary rotation ("cor&...
- 11
1
vote
0
answers
47
views
One more incorrect result of FunctionMeromorphic and FunctionAnalytic
Two years ago I submitted a bug in FunctionMeromorphic (That bug still persists in 13.2.). Here is one more incorrect result in it and ...
- 21k
1
vote
2
answers
47
views
Sorting by power
I want to sort this table by column "d" such that Mathematica should also take the exponential values into account. Can somebody help me here?
- 11
2
votes
1
answer
67
views
Limit of Taylor coefficients
I want to calculate the following limit:
b[n_] := (D[1/(1 - t), {t, n}] /. {t -> 0})/Factorial[n]
Limit[b[n], n -> ∞]
(* Indeterminate *)
where ...
0
votes
0
answers
33
views
Hyperbolic Fourier series in Mathematica?
The hyperbolic Fourier series has nonlinear periodicity, and can be applied for wave modeling.
https://arxiv.org/abs/2110.00148
The proof herein is quite laborious to reproduce here, but my question ...
- 991
1
vote
1
answer
47
views
Function f[a__][b__] with double inputs and definitions/automatic rules
I have a function of the form f[a___][b___] which I would like to apply rules to, for example:
...
- 717
2
votes
1
answer
29
views
Run Initialization in Manipulate Manually
Although I have received a lot of help, there is a rather difficult question.
Let we have a system with parameter:
$$x_{n+1}=x_n^p$$
As long p changes, we have to ...
- 817
0
votes
0
answers
46
views
A question about integrals and numerical integration
I have a function $f(r)=(1+r/2)^{(-5/r)}-1/r$ and I need to solve the integral of its reciprocal. However, I failed. Is there a way to get the analytical formula of this integral? If it is possible to ...
- 61
1
vote
1
answer
46
views
Graphing perpendicular vectors to a 3D graph
I am brand new to mathematica,
I was wondering how can one obtain a curve similar to this one :
Where the vectors are perpendular .
Thanks for your help
the curve is $f(x,y) = \sin(xy)$
Here is the ...
- 11
1
vote
0
answers
21
views
Can Mathematica import uv information from 3d model?
Question1:
Does mathematica's supported 3d file format can import uv information such that we can split the model polygons and keep the texture?
https://en.wikipedia.org/wiki/UV_mapping
Question2:
If ...
- 8,429
7
votes
2
answers
258
views
Dot Product and Simplification
How to simplify the expression
a b . x/((a b) . x)
Where a is a scalar and b and x are vectors.
I have tried the usual Simplify, FullSimplify, TensorExpand etc. ...
- 775
6
votes
3
answers
248
views
How can I check if the matrix is of the following form?
$\left(
\begin{array}{cccccc}
-a & 0 & 0 & 0 & 0 & 0 \\
0 & a & 0 & 0 & 0 & 0 \\
0 & 0 & -a & 0 & 0 & 0 \\
0 & 0 & 0 & a &...
- 3,399
1
vote
1
answer
43
views
Partition with cyclic padding
I am using v12.2.0 on Win7-x64.
The difference between case 1 and case 2 is that the list being partitioned has 5 elements vs 4 ...
- 28.7k
-4
votes
1
answer
56
views
Please show code for mathematica [closed]
. Using Mathematica, solve the following differential equation system by completing the following steps:
(𝐷 + 2)𝑥 + 𝐷(𝐷 + 1)𝑦 = 3𝑒^−𝑡
𝐷𝑥 + (𝐷 + 1)𝑦 = −3𝑒^𝑡
a. Use DSolve to solve the ...
- 1
1
vote
1
answer
58
views
How to convert a Whitaker function to a Coulomb function?
$$
\frac{d^2F}{dx^2}+\left[ 1-\frac{2n}{x}-\frac{l\left( l+1 \right)}{x^2} \right] F=0
$$
The solution of the above equation is the Coulomb function.
$$
\frac{d^2w}{dz^2}+\left[ -\frac{1}{4}+\frac{k}{...
- 319
1
vote
1
answer
45
views
ContourPlot has weird wavy line
I have been using ContourPlot for a complicated but analytic function, which does not need numerical calculations. I am confused to see the result looks like the following picture, where the lines ...
- 21
0
votes
0
answers
41
views
BoundaryDiscretizeRegion and DiscretizeRegion Commands Generate Meshes with Unwanted "Hula-Skirt" Flashing
Mathematica V13.2
This is a generalized problem. The provided sample involves singularity (1/x or 1/0) candidates, such as Sin[x]/x. Singularities or division by zero equations are the primary focus ...
- 21
0
votes
1
answer
52
views
Why these two ways of interpolations give different results?
Consider a data file distr.dat. It is a tabulated grid in the form x1,x2, func[x1,x2]. I interpolate it in two different ways:
...
- 5,112
2
votes
1
answer
42
views
Plot elements of a time dependent matrix
The matrix that I wanna plot the elements are complicated, this matrix is just an example:
...
0
votes
1
answer
47
views
How to compare the numerical with the analytical solution of PDE?
Given the analytical solution
...
0
votes
0
answers
44
views
Controlling my Drone
I have the ambitious plan to paint a wall using a drone. And I would like to do that with Wolfram mathematica.
Does anyone have experience flying a drone with their laptop?
Is it possible to control ...
- 2,393
0
votes
2
answers
91
views
Why does Minimize return a wrong answer?
I want to find the minimum of the following function, but get a wrong result. What am I doing wrong?
...
- 1
3
votes
2
answers
86
views
Computing constrained tuple efficiently
I was wondering what would be the fastest/most efficient way to compute the elements of the set
$$\left\{ x\in\mathbb{Z}^{d} \middle| \sum^{d}_{i=1}|x_i| \leq n \right\}$$.
I think I could use Reduce,...
- 147
3
votes
1
answer
96
views
Computing the unitary operator that diagonalizes a matrix
Hello. I am learning in Mathematica how to obtain the unitary operator that allows us to diagonalize the matrix M. Although with U^{-1}.M.U am able to obtain the answer: why doesn't the program ...
- 133
2
votes
2
answers
72
views
Don't understand an evaluation with BezierFunction
I don't understand the source of the failure of the following attempts to solve an equation involving the following very simple BezierFunction.
...
- 13k
-1
votes
0
answers
20
views
Travelling Tournament Problem (TTP) IL.P [closed]
"I am attempting to solve the Travelling Tournament Problem (TTP) using the Python library Pulp. However, I encountered a problem with the scheduling constraint, which was not accepted. All the ...
1
vote
0
answers
41
views
Hyperlinks in plain text not preserved when saving in PDF format in Mathematica V13
I have a notebook containing hyperlinks, but when I save it in pdf format (print to PDF) the hyperlinks are not blue and not clickable.
According to Hyperlinks not preserved when saving in PDF format ...
- 121
0
votes
1
answer
45
views
Can someone please explain where I am going wrong in the given argument? Is it obvious that $f(m,s)>0$?
I have a two-variable function $f(m,s)$ for real $m>0$ and $s>0$, and as the first picture shows, it seems that it is always positive; on the other hand, I can easily find the minimum of $f(m,s)$...
- 161
0
votes
1
answer
50
views
Integrate doesn't give a result for non-linear functions
I use Acegen for Finitie Element formulation that gives out residuals and tangents by taking in the field values as inputs. For this in my residual formulation I need to integrate a nonlinear term ...
- 1
0
votes
1
answer
80
views
Don't understand the number of levels of "Flatten"
I have a data
data={{{-(1/2), -(3/2)}, {1/2, -(1/2)}, {3/2, 1/
2}}, {{-(3/2), -(5/2)}, {-(1/2), -(3/2)}, {1/2, -(1/2)}, {3/2, 1/
2}, {5/2, 3/2}}}
I want to ...
- 1,180
-1
votes
1
answer
58
views
Closed form of $\int_{0}^{1} \frac{x\log x\log(\frac{1+x}{1-x})}{1-x^2} dx$ [closed]
I need a closed form using Mathematica or otherwise of the integral $$\int_{0}^{1} \frac{x\log x\log(\frac{1+x}{1-x})}{1-x^2} dx $$
This integral converges see here.
I am requesting a code with ...
- 97
-1
votes
1
answer
53
views
Calculate the value of an interval [closed]
I want to calculate the maximum value of the formula given in the code, but it is obvious that my writing is incorrect. How should I modify it?
...
- 53
1
vote
2
answers
43
views
Multilinear Function
I have a totally antisymmetric function of n arguments, f[a,b,c,d] = -f[b,a,c,d], which I would like to be multi-linear, e.g.
...
- 717
0
votes
1
answer
30
views
How to draw a function image within multiple interval definition domains? [duplicate]
Plot[x^3, {x, -1, 3 || 7, 10}]
Note that the intervals of the function are separated. There are two intervals, (- 1,3) and (7,10)
- 797
-1
votes
1
answer
50
views
How to graph the gradient of the function Sin(x,y)? [closed]
I tried graphing the gradient of the following function but i can't manage to do it, anyone can help me please
- 11
0
votes
1
answer
60
views
Recording results of Manipulate
I'm studying the effects of some parameter on a complex system.
When we change the parameter, the system is converted and we need to write each new state to the list.
Problems encountered in using <...
- 817
0
votes
0
answers
21
views
3
votes
1
answer
238
views
Prediction Algorithm [closed]
Trying to identify what algorythm I need to use to predict a battery full time (100%), based on historic data (charge rate is variable).
I suspect it's some form of linear regression of a sort, ...
- 31
0
votes
1
answer
32
views
How to find the value range of a function with multiple intervals in the definition domain?
FunctionRange[(2 Sqrt[3] (k^2 + 1))/(
3 k^2 - 1), {k, k > 1/Sqrt[3], k < -1/Sqrt[3]}, y]
The above function argument has two interval ranges k > 1/Sqrt[...
- 797
0
votes
1
answer
50
views
