# All Questions

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33 views

### Conditional flow of cells?

I’d like to create interactive notebooks for class use, showing the step by step calculations needed for solving simple structural engineering problems, with the corresponding text paragraphs in cells ...
• 293
41 views

### What Kind of plot is this one?

What kind of plot is this one? How to build one of these? This is a dataset with bins with different sizes. Plot taken from http://go.warwick.ac.uk/wrap/77362
25 views

### NMinimize and DE

I would like to use the Differential Evolution option of NMinimize to find the "optimal" solution for the hyper-sphere function defined as follows, ...
48 views

### Finding zeros of a complex Airy function

I want to find the zeros of the solution to this ODE DSolve[{y''[x] - (I x - 2) y[x] == 0, y[0]==0,y'[0]==1}, y[x],x] I use ...
• 269
29 views

### How to get a rational solution of the linear system efficiently?

I got a large linear system ...
• 51
29 views

### Simulate geometric brownian motion and use generated data for calculations

I want to generate a geometric brownian motion A with mean $MuA$, variance $SA$ and starting value 0.05. I do the following: ...
31 views

### Prevent google doc from changing the (c) to a copyright symbol [closed]

In google docs, when I try to write (c) and after pressing a space bar, it automatically changes it to a copyright symbol. Is there any way to avoid it?
1 vote
34 views

### Is there a better way to Distribute after rule substitution?

Here I'm considering a problem related to rule substitution. In the simplest case, it can be shown as follows: ...
44 views

### FullSimplify a long list

I have got a list of very long terms and Mathematica can not fully simplify it, but I can simplify each term separately. How I can replace the separately-derived-results in the list, instead of those ...
• 57
76 views

### How to remove error in NIntegrate

I want to solev NIntegrate in two dimension. But when i run the code i got Throw::nocatch: Uncaught Throw[-HolonomicDifferentialRootReduceDumpy[NIntegrateLevinRuleDumpx]+(...
1 vote
50 views

### How does Mathematica's B-Spline NURBS work?

I'm finding that Mathematica is getting hung up on a numerical integration and I suspect I can do it faster myself in C++. I can scoop the control points of the BSplineFunction out of the ...
34 views

### I want to solev NIntegrate in two dimension [duplicate]

I want to solev NIntegrate in two dimension. But when i run the code i got Throw::nocatch: Uncaught Throw[-HolonomicDifferentialRootReduceDumpy[NIntegrate...
205 views

### Droplet of water-alcohol mixture spreading due to evaporation-caused surface tension gradient

I am trying to solve a coupled system of PDEs for 2 functions h[t,r] and c[t,r], with initial conditions of ...
• 41
42 views

### Coordinates of Vertices of Simple Cubic Lattice

I would like to find the Vertex coordinates (x,y,z) of the Lattice Data for a Simple Cubic structure. I need a list of the vertex coordinates of the Simple Cubic Lattice where if I send the commands:...
56 views

### Visualizing order of operations

TreeForm[HoldForm[ (9-2^2+10 8)/9]] produces this: Is there a way to use Divide instead of ...
• 398
29 views

### FunctionCompiling lists of things

I have a compiled function that works on a list of some atomic type e.g. strings, but also want it to work on lists of others (e.g. integers, reals, symbols, etc). Moreover, nothing in the code has to ...
• 3,720
76 views

### Algorithm for the resolvent of a matrix, and LUBackSubstitution

Suppose A is a complex n x n matrix where n is quite big, given as a numeric array. For many ...
51 views

### Plotting a long and complex airy function

I try to plot an Airy function ...
• 269
33 views

### Is is possible to specify use of a non-Euclidean norm for NonlinearModelFit

When using NonlinearModelFit with Method->NMinimize I have received the warning message NonlinearModelFit::lmnl, which includes the text ""The model -cVar+Log[1+0.00821596 t] is linear in ...
• 83
1 vote
68 views

### Avoid imaginary result FindRoot

I have a code where I'm using FindRoot for the equation toroottp. I plug in some sample values on ...
• 326
62 views

### Product of different differential operators

I need to define a multivariable differential equation of the type  \mathcal{D}=\Theta_1^2-z_1(-\Theta_1+\Theta_2+\Theta_3+\Theta_4)(1+\Theta_1+\Theta_2+\Theta_3+\Theta_4)\\ \;\;\;\;\;\;\;\;\;\;\;\;\...
• 21
100 views

### Is function MiniMaxApproximation equivalent to Remez algorithm?

I'm looking for function calculating polynomial of best approximation (in sense of uniform norm) to given function $f(x)$ on interval $[a,b]$. I know Remez algorithm doing this. In ...
• 31
20 views

### Change value of a single input variabe to get out put results for each case the input single value is changed

I would like to put random values like (s = 0.1, 0.7 , 0.4, 0.15, 0.18) to get the output results which are ( X and Rn ) for these values in different excel files or in the same excel file ,instead of ...
• 37
63 views

### Check Eigenvalues and Eigenvectors are correct [closed]

I have a matrix: J = {{0, -λ (1 + φ)/τ}, {-(1 + φ)/τ, δ}}; And I compute the Eigenvalues and Eigenvectors as follows: ...
39 views

### It is not possible to build a 3D graph of the inverse Fourier transform

That's what I need to do. There is a function Φ[α,β,z] in which the replacement of k1 and k2 is used. Thus, an analytical representation of the integral characteristic of the solution of the problem ...
62 views

### Roots of a transcendental equation with unknown a complex number

I am trying to solve a problem and I got stuck with a complicated transcendental equation. I intend to find these roots. Here, $\omega$ is a complex number, whose imaginary part can be positive or ...
53 views

### Why FullSimplify return {} on this solution of ode?

I was calling FullSimplify with timeout on solution of ode. The idea if it timesout, then will try Simplify on same solution ...
• 108k
36 views

### How to plot the vector field $\frac{1}{s}\hat{\phi}$?

I am asked to plot the vector field $\frac{1}{s}\hat{\phi}$ over the cylindrical coordinate system, however, I don't know how to plot, either the suitable plotting software. Any help please?
69 views

### Can't simplify expression with square roots of square roots

I'm very new to Mathematica, and I've been using it to evaluate some symbolic expressions in my research that are too complicated to do by hand. However, some of them don't simplify when it is obvious ...
• 21
51 views

### Formal variables no longer simplifying well on new Mathematica version?

I work with a lot of formula manipulation, modular forms etc. For example, the Dedekind eta function comes up a lot, and I'm often interested in the following sort of code: ...
• 1,287
118 views

### I can't find the reason for the flat chart [closed]

That's what I need to do. There is a function Φ[α,β,z] in which the replacement of k1 and k2 is used. Thus, an analytical representation of the integral characteristic of the solution of the problem ...
77 views

### A problem with ParametricPlot

I have a problem with rendering d3 (blue color), at the points of intersection of the red curve it makes vertical blue stripes, how do I fix it? Picture: ...
30 views

### VideoJoin changes phone videos from portrait to landscape [closed]

After using VideoJoin on two phone videos, the aspect ratio changes from portrait to landscape. How can I keep the portrait mode?
• 250
1 vote
67 views

### Reduce or Limit to have positive value!

I would like to see where this function is positive ??!! Reduce[{Tanh[x]/Sqrt[-1 + Tanh[x]^2] > 0}, x, Reals] thank you.
82 views

### Draw phase line associated to slope field

I have an autonoous differential equation dx/dt = x(1-x) dxdt[x_] := x*(1 - x) I plotted the slope field with a few solutions (left) and the constant solutions (...
1 vote
36 views

### Execute wolfram command from java & j/link along with set of variables [closed]

I have been trying to execute some expression/formula which may have multiple variable, and I want to set values(like how we do on kernel command tool). We are using J/Link to connect kernel from java....
• 11
29 views

### Use of Part alters line colours in Plot [duplicate]

I stumbled upon some odd behaviour in Plot that does not really make sense to me. I stumbled on it with a more complicated scenario, but a distilled demo is below. ...
• 366
257 views

### Problem with Spectrogram

Some time ago I wrote a program to analyse a short segment of music and plot as a spectrogram in Mathematica. It allows one to find the notes in a weird chord for example. The example below is from ...
102 views

### FourierCosTransform bug?

FourierCosTransform[Cos[(k + p) z], z, q] gives correct result ...
47 views

### 3d Contour Plotting

I would like to plot three 3D-contour plots in the region $x,y,z >=0$ and $x+y+z<1.$ The functions which I would like to plot are as follows ...
• 115
53 views

### How to turn off File Browser prompt?

Is there a way to turn off this feature? It is very slow and totally unnecessary for me. I have tried to look for a setting in preferences but I couldn't find the right box to untick.
1 vote
197 views

### Is it possible to separate two signals in Mathematica?

I have asignal and I would like to decompose it into two.. this is the datasetTot of both signals ListPlot[datasetTot, PlotStyle -> {Black, Black}] I know ...
• 2,997
29 views

### How can I change fractions as tick labels with real numbers?

When using HorizontalGauge or VerticalGauge the scale divisions are frequently labels with fractions (1/5, 2/5) etc., which looks terrible and is hard to read. I have not found a way to force labels ...
• 1
1 vote
70 views

### How to make warning and errors messages on console print in RED? so easy to see them?

When I run large computation with 1,000's of iterations, then later look at the console looking for any errors or warnings generated, it is hard to locate them scrolling up and down, as the color of ...
• 108k
52 views

### Combine two contour plots with region function in one with common bar legend

I have the following two contour plots ...
65 views

### How to plot 3D spherical graph using x y data?

I have a problem in which the temperature is given at different radius for spherical ball. The temperature does not vary in theta and phi direction. The 2D representation is shown below: The radius ...
61 views

### gen 2 and 3 surface generation [closed]

Is there someone who uses Mathematica, and can help me to generate these images for a project? We don't have free access from the university and I can't find other free generators to be able to ...
324 views

### Modify one list according to degeneracies of another

I have two lists, each with four elements, let's say listA = {0.3, 0.6, 0.6, 0.9} listB = {0.1, 0.2, 0.3, 0.4} Notice that the second and third element of ...
• 1,895
70 views

### Piecewise based on the length of the list

I want to create a piecewise function that depends on the length of the list. Let's say I have a list, and a corresponding piecewise function: ...
• 703