All Questions
83,891
questions
0
votes
0
answers
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
0
votes
0
answers
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
0
votes
0
answers
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,
...
3
votes
1
answer
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
0
votes
0
answers
29
views
0
votes
1
answer
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:
...
-1
votes
0
answers
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
1
vote
0
answers
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:
...
- 21
0
votes
0
answers
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
0
votes
1
answer
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]+(...
- 13
1
vote
0
answers
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 ...
- 11
-3
votes
0
answers
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...
- 13
4
votes
1
answer
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
-1
votes
0
answers
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:...
- 79
2
votes
1
answer
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
0
votes
0
answers
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
4
votes
0
answers
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
0
votes
1
answer
51
views
0
votes
0
answers
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
1
answer
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
2
votes
2
answers
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
3
votes
2
answers
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
0
votes
0
answers
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
2
votes
1
answer
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:
...
0
votes
0
answers
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 ...
- 1
0
votes
0
answers
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 ...
7
votes
0
answers
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
-1
votes
0
answers
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?
2
votes
1
answer
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
0
votes
0
answers
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
-1
votes
0
answers
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 ...
- 1
0
votes
0
answers
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:
...
0
votes
0
answers
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
1
answer
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.
5
votes
1
answer
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
0
answers
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
0
votes
0
answers
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
6
votes
1
answer
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 ...
3
votes
1
answer
102
views
0
votes
1
answer
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
6
votes
1
answer
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.
- 285
1
vote
1
answer
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
0
votes
0
answers
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
1
answer
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
0
votes
0
answers
52
views
Combine two contour plots with region function in one with common bar legend
I have the following two contour plots
...
- 1
0
votes
1
answer
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 ...
- 3
0
votes
1
answer
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 ...
7
votes
6
answers
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
2
votes
2
answers
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
0
votes
0
answers
49
views
Syntax for parallel processing
I have a Do[] loop that references a few global variables but doesn't modify anything. The only output is appending data to an external file. The order of appending doesn't matter, I just can't have ...
