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Questions tagged [error]

Questions seeking help understanding error messages and fixing errors.

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20 views

ParallelTable with NIntegrate and Append

to evaluate a NIntegration inside a loop, so to do faster, I have try to use the ParallelTable, the program runs without error, but get the wrong results. Using Table I get for the list: {0.2, 0, 0....
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0answers
90 views

Numerical integration of damped wave equation

I am trying to solve the equation $$ \frac{d^2u}{dt^2}-\frac{d^2}{dx^2}\left(c_s^2u+\nu\frac{du}{dt}\right)=0 $$ with initial conditions $$u(x, 0)=0$$ $$\frac{du}{dt}|_{t=0}=0$$ and boundary ...
3
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0answers
57 views

Why does FindInstance take so long: It is faster with more restrictions than with less?

A support case with the identification [CASE:4347836] was created. I just noted this little puzzle on twitter by Brillant.org: \begin{align} A B C\\+ BCA\\ = CDE \end{align} Given that $A$ is even ...
4
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3answers
147 views

NDSolve will try solving the system as differential-algebraic equations but it didn't get the solution

Please help me deal with this kind of question about ODEs. My codes are as follows ...
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0answers
21 views

Fitting B-Spline to the data and Plot the curve error [on hold]

I am trying to fit B-Splines to the data given and plot the curve on the same graph with the data. My end goal is to use my B-spline in order to predict the value f(750). Although, nothing is running ...
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1answer
35 views

Singularity or stiff system in NDSolve

I have the following piece of code ...
5
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1answer
53 views

Why does this stiff BVP return unevaluated but a similar IVP produce a solution?

In Solving a steady-state viscous Burger's equation with NDSolve, one question involves the following problem: ...
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1answer
33 views

Compiling simple parallel function gives inconsistent results and errors

Im trying to compile the following function: ...
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1answer
77 views

Why is “1” not a valid variable? Why is there not a function plotted in the Plot function? [duplicate]

This is my code for playing this kind of stuff ...
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0answers
30 views

Mathematica Error Message Help [duplicate]

when using NMaximize[], I keep getting the following error message: Can someone please explain what <<99>> + <<86>> = 0 means?
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2answers
66 views
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0answers
33 views

FindMaximum error (not a real number)

For the code below, I get several error messages once I click the "Enable Dynamics" button. However, once I run the code, the output works fine, so, if that is all I wished to do, I would just live ...
1
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1answer
84 views

Having trouble with Part

I'm very new to Mathematica. I'm just trying to plot some data, but Mathematica says there isn't a 7th element my data which is an array of 7 elements. The code before the plot is here: ...
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0answers
38 views

Need help with the “step size is effectively zero; singularity or stiff system suspected” message

I'm trying to solve a system of ODEa, and I always get a message saying NDSolve::ndsz: ..step size is effectively zero; singularity or stiff system suspected. I tried ...
2
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0answers
67 views

Error Message for GrammarRules and GrammarApply

I have been struggling with the following issue regarding an irregularity when deploying and applying GrammarRules. Specifically, it often takes several failed attempts before the execution is ...
2
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1answer
25 views

DensityPlot: Error messages and strange bar legend

Bug introduced in 11.1.1 or earlier and persists through 12.0 I want to plot the following DensityPlot with axes given by Trr ...
2
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2answers
52 views

Error in a simple plotting code [closed]

I have the following code: ...
2
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3answers
103 views

Problem with NSolve with Logarithm

I have an issue with NSolve, and I think it's because of the logarithms : ...
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3answers
68 views

How to resolve Overflow error in FindFit method?

I am using FindFit function in order to fit my data and get two parameters: c and m. The function that I am using has the following form: ...
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0answers
30 views

Why is my code for density using Folner Sequences giving incorrect values? [duplicate]

I am creating a code that calculates or approximates $$D(S\cap[a,b])=\lim_{n\to\infty}\frac{\left|S\cap{F_n\cap[a,b]}\right|}{\left|F_n\cap[a,b]\right|}$$ where $D$ is the density of $S\cap[a,b]$ (...
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2answers
111 views

Numerical resolution of non-linear coupled ODEs

I have problem with my code in Mathematica. I have introduced the set of coupled non-linear ODES. This is the resolution part: ...
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1answer
21 views

Error more dependent variables than equations [closed]

This may be a stupid question but I can't figure out what I'm doing wrong, my mathematica code rejects the equation as having too many dependent variables, Error: There are more dependent variables ...
3
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2answers
96 views

Table to generate colossally abundant numbers not working

I'm trying to tabulate the first 8 colossally abundant numbers defined by critical epsilon values, with epsilon listed in ...
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1answer
47 views

What is wrong with my function call? [closed]

I'm writing a function and when I execute it, I get a message saying: ... function has no opening ]. If I remove the right square bracket, I get a message saying: ... needs more input Here ...
6
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1answer
380 views

Can NDSolve address spherical gravitational collapse?

As far as I know spherical gravitational collapse -of central importance to theoretical physics- is thought to be out of the scope of Wolfram Mathematica. However there are cases, as in this article,...
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1answer
67 views

How do I skip to the end of a loop when a compiled function yields an error?

This is something of a follow-up to my question In an iterative process, how does one simply bypass a step producing an error? which I have been so far (thick-headedly) been unsuccessful in ...
3
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1answer
65 views

Unexpected error when implementing FEM in MoL SpatialDiscretization

I cannot figure out why the following piece of code ...
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0answers
23 views

Error messages in a notebook

I write on the Mathematica notebook NSum[(1 + k^2 + l^2 + m^2)^{-1.75}, {k, -Infinity, Infinity}, {l, -Infinity, Infinity}, {m, -Infinity, Infinity}] and it ...
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2answers
78 views

In an iterative process, how does one simply bypass a step producing an error? [closed]

This is undoubtedly rather elementary, but the remedy escapes me presently (and does not, as far as I can see, readily appear in Help). I'm engaged in an iterative process with several computations ...
2
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0answers
36 views

DSolve 4 variables function error

Mathematica version: 12.0.0.0 I'm trying to solve 2 basic differential equations; ...
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0answers
34 views

How to include `TimeConstraint` in `EulerEquations`? Is there any error here?

There is a complicated statement which takes a long time to compute. IS THERE ANY ERROR IN THE ATTACHED PICTURE? If YES, how can I include TimeConstraint of ...
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2answers
39 views

NDSolve: How to perform a reverse integration consistency check?

Let there be the following NDSolve code: s = NDSolve[{y'[x] == y[x] Cos[x + y[x]], y[0] == 1}, y, {x, 0, 30}] I think it ...
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0answers
59 views

Stiff system of ODEs

I'm trying to solve a system of differential equations with NDSolve, but I get the error message: NDSolve::ndsz: At lnP == -21.0018, step size is effectively ...
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0answers
42 views

Error message from FindRoot

I am getting the following message when I evaluate a call to FindRoot: The line search decreased the step size to within tolerance specified by AccuracyGoal and ...
1
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0answers
44 views

Encountered non-numerical values at (ParameticNDSolve/NDSolve)

I have the following problem: Even though I defined every other constant in the code, using either NDSolve or ParametricNDSolve, ...
0
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1answer
119 views

Create a Miura origami pattern?

I want to solve the below code to create an origami pattern ...
1
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1answer
60 views

Strange Startup Error Messages

Seemingly out of nowhere when I open Mathematica a messages window pops up with these two warnings. This issue starting occurring after no changes where made. ...
4
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1answer
45 views

Evaluate calls my function multiple times when the function generates an error

If I execute a line of code with Evaluate I find some unexpected behavior when the code returns an error. Here is a minimal example. Let ...
4
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0answers
64 views

Double summation giving unexpected result

The expression (in a notebook with Wolfram Mathematica 12.0.0) Sum[s[i, j] - s[j, i], {j, b}, {i, b}] Produces the result 1/2 b EulerPhi[b] Can anyone ...
0
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2answers
79 views

Array of polynomials

So I have a big list of 75 polynomials which I need to apply a sequence of operations to. My original program (an extract of which is below) worked fine: ...
6
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2answers
391 views

Is it possible to Clear (recover memory from) a specific index to a variable, while leaving other indices to the same variable untouched?

Consider the following method commonly used to clear a typical variable: ...
3
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2answers
58 views

“Automatic is not a valid StreamPoints specification”

If I run StreamPlot[{a, b}, {a, 0, 10}, {b, 0, a}] the kernel hangs, and I have to restart it. I also get the error message StreamPlot::strmpts: Automatic is ...
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0answers
61 views

SMSCorrect internal: Incorrect structure-2

Does anyone know what does the error: SMSCorrect internal: Incorrect structure-2. refer to? I mean, in general. Specifically, I get it from the following code. ...
3
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1answer
447 views

General::ivar 0 is not a valid variable when using Series in Plot

I have been having some trouble graphing a Taylor series approximation (Series). ...
2
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3answers
93 views

Problem in NDSolve (Mathematica 7)

Following a piece of program ...
1
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1answer
60 views

How to fix slow covergence and highly oscillatory integrand issues?

I'm trying to numerically solve an integral in a specific region and then to visualize it as follows. ...
2
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0answers
44 views

Error in PDE: Length of Derivative operator

I am trying to solve Poisson's equation in a cylinder with Dirichlet boundary conditions for the top, bottom, and sides of the cylinder, but I am getting the following error from NDSolve: ...
0
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1answer
32 views

Error Code 414 while trying to do a substitution

I was trying to see what would happen if I let d=q in the following equation: ...
3
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0answers
82 views

How to use an interpolating function as an intial condition for a PDE? [closed]

I want to be able to approximate a PDE, but my eigenfunction is an Interpolating function. Is there a way I can use an interpolating function as an initial condition in the PDE. For Example: ...