1
vote
0answers
6 views

Low accuracy while solving a multi-variable equation numerically

My question is as following: I was trying to make a function Vs2[r] with two parameters fit a set of conditions. Vs2[r]: ...
0
votes
0answers
4 views

NDeigensystem returns error due to mesh discretization when calculating vibrations of a cantilever

There was an transcription error in the code I provided in a previous post: NDeigensystem returns complex non-hermitian error for the calculation of vibrations of a cantilever This resulted in it ...
1
vote
1answer
33 views

How to draw a moving point with time?

I am new to Mathematica. Try to draw a point moving with time. Like at t=0, a point is at p1(coordinates are random numbers); at t=1, this point is at p2. And there is always ONE point on the graph. ...
-1
votes
0answers
32 views

Creating Vector Field Plots for an Implicit Equation [on hold]

I am having difficulty creating a vector field plot for the implicit equation Log[(2x-1)/(x-1)] == t (* Did your best to use Mathematica syntax *) Where ...
4
votes
0answers
46 views

Why is Random[ ] faster than RandomReal[ ]?

As of version 6, Random[] was superseded by RandomReal[ ] etc, but both still work perfectly well. Playing with some timing ...
0
votes
0answers
35 views

How to make image3d smaller? Is `ImageResolution` useful?

I want to make the output of Image3D much smaller. For example ...
1
vote
1answer
89 views

How do I plot a ribbon in Mathematica?

I know mathematica has a built in tube function, but I want to be able to change the parameters of a ribbon and visualize that. Is this possible? How do I do this?
0
votes
0answers
32 views

Unable to plot higher order polynomial equation using NSolve and contourplot

I have a polynomial equation in 'a,b' and I am trying to plot a curve between 'a' and 'b'. Both NSolve and ContourPlot works well upto 'a=15' , but after that the plot has scattered points. Is this ...
3
votes
1answer
58 views

I want to compute the derivative of Black and Scholes option

Good evening to everybody, my question is about computing the derivative of a Black and Scholes option and to draw it. My code is ...
0
votes
0answers
17 views

MatrixForm in Mathematica [duplicate]

I wanted to do subtractions between to matrices and I did the following ...
0
votes
0answers
35 views

Why doesn't mathematica evaluate the cells?

I have the following code in mathematica. Everything was ok and I was simplifying but suddenly mathematica crashed and after that it seems that it doesn't evaluate the functions. ...
0
votes
1answer
47 views

how to generate a 3d graph of HCP crystal structure [duplicate]

I am confused with lattice parameter and the basis. The structure I generated is not HCP. To verify this, one could use this plotting function from the answer to Can a LatticeData image be displayed ...
0
votes
0answers
23 views

how to plot many curves for different values of a certain parameter [on hold]

how to plot many curves for different values of a certain parameter of a function? how to plot many curves for different values of a certain parameter of a function? i.e. i need to get one figure ...
5
votes
3answers
50 views

How to define a complicated function inside the body of Compile?

I want to compile a function in a way to keep its memory footprint down. In the example below, I am trying to compile a function f that makes three calls to ...
2
votes
1answer
53 views

How to get the analytical solution of this equation set

There is a equation set: {2 x^2 + 49 - 7 x - 2 x Sqrt[x^2 + 49 - 7 x] Cos[rad] == (7 - x)^2, 2 x^2 + 49 - 7 x - 2 x Sqrt[x^2 + 49 - 7 x] Cos[rad + Pi/3] == 49} ...
1
vote
2answers
38 views

Manipulate slider freeze, and empty value in box

Here's a MWE code to show two problems I'm experiencing with the sliders and their value box, under Manipulate : ...
0
votes
1answer
42 views

How to make an empty list inside a module program? It consatly spews errors [duplicate]

Okay, so, I'm trying to write a program within the module. It goes like this: create empty list, join it with a sample from a certain set called MyList, and then repeat it certain number of times. ...
0
votes
1answer
49 views

NumberForm pesky warning from Manipulate

I'm using the NumberForm command inside a Manipulate environment, and in some special cases Mathematica gives a pesky and mostly useless warning message : NumberForm::sigz: In addition to the ...
2
votes
0answers
18 views

weird behaviour of Listable fortran Librarylink function: different result each evaluation

I am working with fotran librarylink function currently. In this post, I will show some weird result of Listable fortran librarylink generated by intel compiler under windows (I tried gcc on linux the ...
2
votes
1answer
57 views

Is there a bug of InverseDistanceTransform?

This is a example of documentation about InverseDistanceTransform. But this is my picture But it doesn't work: ...
11
votes
3answers
251 views

Partitioning a list when the cumulative sum exceeds 1

I have a long list of say 1 million Uniform(0,1) random numbers, such as: dat = {0.71, 0.685, 0.16, 0.82, 0.73, 0.44, 0.89, 0.02, 0.47, 0.65} I want to ...
0
votes
1answer
60 views

what do those signs #1, #1^2, #1^3, & mean here? [duplicate]

I have read common pitfalls page and the documentation page but I still don't understand what do those signs mean here? ...
0
votes
0answers
17 views

Private Style in a StyleSheet with preformatted text

I want to create a new Style in my private StyleSheet. I duplicated the Style "Text" and made some alterations. Now I want that a Cell with this style has an expression already filled in, for example ...
4
votes
1answer
73 views

Why a part of this expression, similar to another, is left unchanged?

An expression has one of its part replaceable and one, strictly similar, that isn't. Please, can you point at the difference ? I can't pinpoint the complication ... The FullForm of ...
1
vote
1answer
41 views

NIntegrate::inumri: error [on hold]

I am getting the following error: NIntegrate::inumri: The integrand c (1-0.6 (1-(1+Times[<<2>>])^0.5)-0.4 (1- (1+Times[<<2>>])^0.5)) (1-0.6 (1-(1+Times[<<2>>])^0.5)-0.4 (1- ...
2
votes
0answers
24 views

WhenEvent and Resetting of Variable in PDE when operation succeeds

I have had success in using WhenEvent to reset or change a variable within NDSolve with ordinary differential equations. My ...
0
votes
0answers
42 views

Fourier-style solutions to differential equations, not piecewise polynomials

NDSolve returns piecewise polynomials. Is there any way I can get a single (non piecewise) function consisting of sines and cosines instead? Sort of a "Fourier approximation" to the solution of my ...
10
votes
1answer
106 views

Plot of $sin(x^x)$ is missing from $x=143$

When plotting the graph of $sin(x^x)$ I noticed that there is no plot from about $x=143$. I don't suppose there is a purely mathematical explanation for this? So, why is there no graph in ...
0
votes
0answers
67 views

Phase space of a system of differential equation

I have a system of three Coupled nonlinear equation of a physical system and i would like to plot the phase space. My system is a chaotic system dependant of three variable dependant of time (l1, ...
2
votes
1answer
45 views

Problems with QueueingNetworkProcess [on hold]

I have a two stage queueing network and want to vary the number of servers at the second node. The input data and the Manipulate command is below: ...
1
vote
0answers
64 views

Possible memory leak in FindMinimum? (MMA v10.0)

So I was running some code when I noticed Mathematica was gulping memory, and after some debugging I think the culprit is found. It turned out the function ...
2
votes
2answers
139 views

Symbolic vs numerical integration

This is related to a question that I asked before but didn't resolve quite well. I want to obtain the solution of the following expression analytically: ...
0
votes
0answers
28 views

File filter in SystemDialogInput

I want to write a SystemDialogInput function that allows user to choose a file from a directory. In the directory, there are two kinds of image files: Atom images: The name of the file is in the ...
3
votes
2answers
68 views

MeshRefinementFunction missing points

I'm doing some FEM on a rectangular region with a spherical cavity: ...
1
vote
1answer
52 views

How to refer a number in a list with two columns, first one is a number and the second one is empty?

Let's say, I have defined a list as list = {{-31, -31}, {52, }, {34, -11}, {-38, }, {78, -44}, {-36,14}, {-9, 98}, {33, 6}, {82, 99}, {-85, -10}} As you can see, ...
11
votes
5answers
242 views

How to extract a contour line (or a region) from a ContourPlot?

Given a ContourPlot with a set of contours, say, this: is it possible to get the contours separating domains with the different colors in the form of lists? ...
1
vote
0answers
31 views

Changing from Cartesian to polar coordinates in partial differential equation [duplicate]

I have a partial differential equation: $$\left(x^2+y^2\right)\frac{{{\partial ^2}u(x,y)}}{{\partial {x^2}}} + x^2\frac{{{\partial ^2}u(x,y)}}{{\partial {y^2}}}=0$$ How to change from Cartesian to ...
6
votes
1answer
113 views

Add terms to nested list

Suppose I have a nested list of the following: list={{1,2},{5,8},{4,1}...} I would like to add a number to each first term of the list. The output would be ...
2
votes
0answers
36 views

Automatic text-wrapping in labels in `TimelinePlot`

Part-related to this question and part-related to this one, I would like to make use of the new features of TimelinePlot in 10.3, but would like to incorporate some ...
1
vote
1answer
27 views

Length in Compile encounter “type Integer encountered in assignment of Type Real ”

Compile[{}, Module[{n}, n = Length[{1, 2, 3, 4}]; n = n/2]] The above code will emit errors Compile::cset: Variable n of type _Integer encountered in ...
0
votes
1answer
42 views

ParallelTable should distribute dedicated evaluation range to different kernels

I have 4 kernels and would like that in ParallelTable: ...
-7
votes
0answers
33 views

Optimization (minimization) of equations with conditions [on hold]

I need to minimize the expression a+(b/3) + c under the conditions: ...
-7
votes
2answers
57 views

How to solve for the eigenvalue in matrix? [on hold]

For which value of $a$ in the matrix {{a,2}, {3,4}} has the matrix eigenvalue of $0$? How to solve it in Mathematica?
6
votes
5answers
153 views

How to generate two group of $n$ random numbers in $U(0,1)$ such that sum of these two groups equal? [on hold]

I want to have two groups of $n$ random numbers $u_i$ and $v_i$ in $U(0,1)$, such that $\sum u_i = \sum v_i$ What I tried is: I can firstly get $u_i$ by ...
0
votes
1answer
21 views

Why can't I change the Magnification in Printout Style in Default.nb

This happens with Mathermatica 10.3.1.0: When working with a notebook, I can choose between different working environments. However, they inherit their settings from Default.nb situated at ...
-2
votes
0answers
41 views
1
vote
2answers
93 views
1
vote
2answers
60 views

intermediate steps of simplification of algebraic expression without evaluation [on hold]

I am using MMA do do some algebra and I need to do some simplification. For example, I have the following expression $$ x^2 \left( \frac{6 \left(2 c_1 x^6+c_2\right)}{x^4} \right)-x \left( 4 c_1 ...
0
votes
1answer
44 views

How to represent one variable in terms of others in a system of equations? [on hold]

I have an pretty complex equation set But when I clicked Ctrl+Enter (a.k.a Evaluate Cell), nothing happened. What should I do?

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