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6 views

Long Execution time of Reduce

I have a set of linear homogeneous equations with 8580 variables. I want to estimate the time Mathematica takes to solve the system, by solving smaller sets of ...
8 views

Use of Mathematica for Machine Learning Course

I am interested in others' experience using Mathematica for machine learning and bioinformatics course curricula. Let me first say that I have been programming with MMA for almost 10 years now (out ...
10 views

Import data from a current web session?

Consider opening a web session such as (Mathematica 11.3) session = StartExternalSession["WebDriver-Chrome"]; ffoxdo[cmd_] := ExternalEvaluate[session, cmd]; ...
11 views

How can I get paired coordinates from the implicite function?

I have equation E^y = x. How can I use Mathematica to solve all of "y" from the desired "x" value. For example, I want to solve for "y" from x = 0.5 , 1 , 1.5 , 2 , .... , 9.5 , 10. The solution ...
15 views

How does Mathematica Find Integer Roots?

I have these two equations: $$f(x)=(\cos(\frac{n}{x} \pi)\cos(x\pi))-1$$ and $$g(x)=\sin^2(\frac{n}{x}\pi)+\sin^2(x \pi)$$ where $n$ can be any integer. These two functions are what mathematicians ...
11 views

Solving Inequalities: Run time too long

I am trying to solve the following system for d: ...
26 views

How to plot a crossection of a ParametricPlot3D?

I'm plotting a surface using ParametricPlot3D. Ideally I would like to plot an intersection of the surface with a plane just as seen in another question (Cross Sections or slices of 3d figures - ...
27 views

Solve coupled PDEs: boundary conditions problem

I need to solve 4 coupled PDEs. Thanks to @xzczd's help, a few days ago I can obtain the solution of the first 2 equations with some proper boundary conditions, see this post. Now, these two equations ...
40 views

The vectorfield for nonauntonomous system?

The model is a nonautonomous system $x'=(2+cos(2 π t))x -0.5 x^2-0.5$ and it can be transformed to the autonomous form by ...
40 views

NDSolve for f[t,s], with initial condition f[s,s]==1

I try to solve integro-differential equation for a function of two variables, where the initial conditions are given with f[s,s]==1. Mathematica does not like such an initial condition, as I get an ...
19 views

Error with StateSpaceTransform: the rule based transformation must be of length 2

I would like to perform a change of variables on the following dynamics system: ...
46 views

How to simplify a three variables expression with Simplify?

I want to calculate the value of $\nabla\cdot\frac{1}{(x^2+y^2+z^2)^{1.5}}(x\hat{x}+y\hat{y}+z\hat{z})$. I used the following syntax: ...
33 views

Why Are Centroid Calculations with Line Integral Wrong?

everyone. I'm currently trying to calculate the centroids of objects using parametric equations and line integrals. I already have a program that can parametrize any shape accurately with a closed ...
43 views

Steiner Tree Approximation

I am wondering about the existence of Mathematica code to find (approximate) Steiner trees in graphs. I know there are a number of algorithms to do so --- just curious if anyone has implemented any ...
25 views

Identify the location of the last entry with a particular value in a list

I have a long list (Table) consisting of "True"s and "False"s. I would like to identify the position in the list of the last entry that takes the value "False". Is there a way to do this?
114 views

Plot the solution from DSolve

I'm trying to solve a differential equation as in the following code: FullSimplify[DSolve[x'[t] == a + b E^(g t) + (c + d E^(-g t)) x[t], x[t], t]] which ...
45 views

DSolve yields a strange character K[1]

I'm trying to solve a linear differential equation as in the following code: DSolve[x'[t] == a + b E^(g t) + (c + d E^(-g t)) x[t], x[t], t] which yields ...
19 views

TargetUnits aren't working as expected on an InterpolatingFunction

Short version: My understanding of the use of TargetUnits in a Plot statement is that if the function being plotted has units, MMA will attempt to convert the output of that function to the unit form ...
78 views

71 views

Wolfram Unable to Integrate [on hold]

I typed in a long integral into Wolfram Alpha and asked it to integrate it however Instead of showing the result or even that it is unable to perform the task it totally ignores the function and only ...