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6
votes
1answer
87 views

How to use a function as a value in an association? [on hold]

I just started learning Mathematica. I was wondering if it is possible to use a function as an value in an association. Ideally, it would be something like this: ...
0
votes
1answer
27 views

Independent scaling of arrowheads and vectors in vector plot

I'd like to scale with independent parameters the vectors and the corresponding arrowheads in a vector plot. The basic code is as follows: ...
0
votes
1answer
80 views

Geodesics in 2+1 Schwarzschild metric

Would appreciate if someone could explain the query that, I am trying to understand the code for timelike geodesic in 2+1 Schwarzschild $(\theta=\frac{\pi}{2})$ where we have taken $M=1$. From this ...
1
vote
1answer
54 views

TimeSeriesAggregate unwanted behavior

Let's take the lst = {{"2019-09-12 00:01:23",1}, {"2019-09-12 00:01:23", 3}, {"2019-09-12 00:01:24",10}}; Assume I want to count events within 1 second. One ...
2
votes
1answer
65 views

JavaGraphics` and CreateDialog don't work with ListPlot in Mathematica 11.3/12

Bug introduced in 11.2 and persists through 12.0, case 4331202 I'm trying to see some plots based on data from a remote cluster as it runs various Mathematica 11.3/12 scripts, so I want to use the ...
0
votes
0answers
27 views

Need help with plotting a probability distribution

I looked through the Mathematica directory and could not find a solution that is right for me. I already solved the mathematics behind this problem, I just need to visualize it in a plot. I am ...
1
vote
0answers
37 views

How to get ListContourPlot to label all of the contours?

I've been trying to get ListContourPlot to work for me on a large set of data, and I feel like I'm failing at the most basic parts of formatting. I've tried piecing together bits of code from here and ...
7
votes
0answers
123 views

The most bizarre kernel crash ever. Kernel crash in Integrate under simple different setups. Unable to find cause

Reported to WRI. CASE:4330461 V 12 on windows 10 64 bit. Note: This problem do not show up in V 11.3. Only in V12. For the last 2 hrs, I've been trying to zoom into why V12 kernel crash when ...
0
votes
0answers
25 views

Correctly Evaluating the existence of Large Solutions

I'm trying to correctly evaluate $$D(S\cap[a,b])=\lim_{n\to\infty}\frac{\left|S\cap{F_n\cap[a,b]}\right|}{\left|F_n\cap[a,b]\right|}$$ where $D$ is the density of $S\cap[a,b]$ (in $A\cap[a,b]$), $[...
0
votes
0answers
19 views

Between n and 2n there is always a prime in between [migrated]

This has already been proved. Does someone know the demonstration?
2
votes
1answer
53 views

Find highest values between two different sets

I have the two following lists: ...
0
votes
1answer
24 views

At how many of these points is f(x,y) (strictly) greater than both g(x,y) and h(x,y)? and

I try too find out the solution but is not work. Please help! This what I wrote:
2
votes
0answers
34 views

Why does accessing the first element of a list yield “List” [closed]

I have a list of expressions listOfStuff = {-(b^(3/2)/Sqrt[7 \[Pi]]), b^(3/2)/Sqrt[7 \[Pi]]} When I try to access the first element of this list like so ...
0
votes
1answer
89 views

TimeSeries behavior unwanted

Was wondering what other options I have when encountering a time series that has two events taking place at the same time. In particular, ...
4
votes
2answers
380 views

Drawing a sequence of circles

For every natural number from 1 to 150, draw a circle centered on the x-axis in that number and with the diameter equal to the number of divisors of the number. I don't know what should I do.
0
votes
0answers
32 views

Solving an integral using assumptions

I am trying to solve the integral Integrate[(Sin(theta))/sqrt((r^2) + (s^2) - 2 rs(cos(theta))), {theta, 0, pi}] with assumptions that ...
5
votes
2answers
83 views

Element-wise multiplication of an array and a matrix

How can I express multiplication of an array and a matrix so that {x, y, z}*{{10, 20, 30}, {0, 1, 2}} gives ...
0
votes
1answer
30 views

How to fit a Weibull distribution function to histogram with unequal bins?

Whenever the function "FindDistributionParameter" is used in Wolfram Mathematica, it needs two inputs: raw data and distribution function. I have a problem where I have have data and I need to use ...
0
votes
1answer
42 views

Numerically solve system of equations with nested variables

I'm trying to solve the following system of equations. The first two equations depend on the variable TeV ...
6
votes
6answers
548 views

How do I count the number of elements in a list which are between two determined values?

I have a long list (apprx. 10000 elements) of numbers. I want to count the number of elements between two determined vallues a and ...
0
votes
1answer
24 views

Error when trying to solve a linear differential equation

I am trying to solve a linear differential equation for the change in scale factor term, $\delta a(t)$, when mass terms are introduced to the equations of motion for General Relativity. The first ...
1
vote
1answer
45 views

Cumulative difference between discrete cumulative distribution functions

I would please like to ask for how to cumulate and plot the difference between cumulative disitribution functions (:=CDFs). Example: ...
1
vote
1answer
50 views

How to get Mathematica to write to disk names that incorpoate a parameter value

Apologies for any duplication as I can't find any trace of asking this before which I think i did. Maybe others have already asked and mine was struck off? I have a program that runs for different ...
0
votes
0answers
28 views

Univariate Gaussian Splitting

I would like to experiment a bit with univariate Gaussian Split libraries. This is essentially a constrained non-linear optimization (minimization) problem. There are multiple formulations of this ...
2
votes
2answers
43 views

Unable to attach a new NetDecoder to a NetModel following the documentation

I am following the documentation in the page https://reference.wolfram.com/language/ref/NetModel.html. I am getting error when I try to execute the code given for attaching NetDecoder for a given ...
3
votes
1answer
66 views

Mathematical Notation

If we use Mathematica notation the following works: Div[Grad[u[x, y], {x, y}], {x, y}] also if we multiply the gradient with a scalar: ...
0
votes
0answers
29 views

How can I use WhenEvent to stop the integration? [duplicate]

I have a questions about stopping the integration. I calculate the function as the following. It gives the message: "At NN=58.7035438......, the step size is effectively zero; singularity or stiff ...
2
votes
1answer
57 views

Computing the definite integral of a fractional polynomial containing sin(x) and x^n

I need to compute the definite integral defined as $$\int_{-\infty }^{+\infty } \frac{\sin ({x_0}\, \omega )-\sin (x \omega )}{(\sin (x \omega )-\sin ({x_0}\, \omega ))^2+(x-{x_0})^2} \, dx\,.$$ When ...
0
votes
0answers
87 views

Complicated Integral output with Unfamiliar Regularized Hypergeometric Function

I need the solution for following integral and it has output in MATHEMATICA as: ...
4
votes
1answer
91 views

Real and imaginary parts of complex logarithm

I need to obtain the real and imaginary parts of the below expression with Mathematica: $(- i a - m^2) \ln(\frac{i m^2}{2 a})$, where $a$ and $m$ are real. So we have: ...
2
votes
1answer
42 views

What is the cycle index polynomial for the trivial group

CycleIndexPolynomial[Cycles[{}], {Subscript[x, 1]}] returns 1. I was expecting ...
4
votes
3answers
403 views

Slow computation of recursive sequences

I want to investigate the asymptotic behavior of the following recursive system: ...
-2
votes
0answers
52 views

series of function

I need help to get the solution for the following equation, that used in scattering theory, as series-expansion using Mathematica, it means in general case for any value of these variables n,l (the ...
2
votes
2answers
35 views

Convert string of tuple of numbers to complex number

I am reading complex number from a file which gives me a list like that ...
1
vote
0answers
72 views

How to make a palette look exactly like a MacOS window?

Is there anyway to style a pallete so that it looks like a native window: ...
0
votes
0answers
20 views

Error after defining a piecewise function

I have the following code: ...
1
vote
1answer
76 views

Solving these equations with a constraint

I have been for long time now try to solve this equation q1[t_] = D[x[t], t, t] - 2 (1/y[t]) D[y[t], t] D[x[t], t] With its complex conjugate ...
20
votes
4answers
2k views

Does Mathematica 11 work with MacOS Catalina 10.15

I just upgraded my macbook to 10.15 and could not open Mathematica 11. I am wondering are there any workarounds to use Mathematica 11 without upgrading to 12? Thank you!
1
vote
1answer
42 views

Manipulating two parameters of a plot

I am wondering if it is possible to manipulate/animate two (or three) parameters in a plot. I would imagine this would work, but doesn't: ...
7
votes
4answers
673 views

Mapping string into integers

Suppose I have the following list, l = {{"b", "c", "d"}, {"e", "b"}, {"a", "b", "d", "e"}} and further suppose I have the following association, ...
2
votes
2answers
43 views

Integrating a function with Max function

I'm trying to evaluate the triple integral $$\int_{0}^{1} \int_{0}^{1-x} \int_{0}^{1-\max(x,y)}1 dzdydx$$ in Mathematica. The code I'm using is simply ...
1
vote
1answer
47 views

Adding units to frame label

I have this code: ...
3
votes
2answers
116 views

Simplification of logarithms

From the Wolfram functions web site it is known that $$\log(z_1)+\log(z_2)=\log(z_1z_2),\text{ for $z_1+z_2>0$}$$ In an answer to this question Alexei Boulbitch wrote a useful function ...
3
votes
1answer
54 views

Can Mathematica check ansatz for solutions of differential equations?

I'm just a beginner learning Mathematica. I'd like to do something with it, but I don't know if it is possible. Suppose I want to solve a system of differential equations, maybe a nonlinear one, and ...
0
votes
0answers
21 views

Error message: Could not access the directory

I ran multiple Mathematica files using the the NoteBookOpen/NoteboookEvaluate options. Now once the run is over, I am not able to save the files. I get the error message - "Could not access the ...
4
votes
1answer
66 views

Reduce memory cost with three matrices multiplication

My program is eating up all my RAM and the operation is related to 3 matrices multiplication, as the code shown below. example code: ...
0
votes
0answers
22 views

Filling Regions (Blocks) of a Binary Matrix with Different Probabilities

This is an extension of the following question: How to generate binary array whose elements with values 1 are randomly drawn, where the most elegant answer was posted in the comments: ...
3
votes
2answers
82 views

Need more equations in PDEs by NDSolve? Bug of mma?

I am trying to solve set of pdes as below ...
0
votes
1answer
19 views

Time Series Arithmetic in v10.0

The following code lets FindPeaks find minima in v10.3-12.0: ...
0
votes
1answer
36 views

Animation in 2D graph

Hi I have a question on how can I create an animated 2 points (dot) that move across the n number of the data point, as shown in my 2D graph? ...

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