# All Questions

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]: ...
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 ...
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. ...
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 ...
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As of version 6, Random[] was superseded by RandomReal[ ] etc, but both still work perfectly well.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 ...
35 views

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

I want to make the output of Image3D much smaller. For example ...
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?
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 ...
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 ...
17 views

### MatrixForm in Mathematica [duplicate]

I wanted to do subtractions between to matrices and I did the following ...
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. ...
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 ...
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 ...
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 ...
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} ...
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 : ...
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. ...
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 ...
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 ...
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: ...
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 ...
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? ...
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 ...
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 ...
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- ...
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 ...
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 ...
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 ...
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, ...
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: ...
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 ...
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: ...
28 views

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 ...
68 views

### MeshRefinementFunction missing points

I'm doing some FEM on a rectangular region with a spherical cavity: ...
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, ...
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? ...
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 ...
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 ...
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 ...
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 ...
42 views

### ParallelTable should distribute dedicated evaluation range to different kernels

I have 4 kernels and would like that in ParallelTable: ...
33 views

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

I need to minimize the expression a+(b/3) + c under the conditions: ...
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?
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 ...
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 ...
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93 views

### I want to plot a list of points with specified t and x[t] coordinates [on hold]

I have this code: ...
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 ...