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Why can e^x be plotted but not xe^x? [closed]

Plot[e^x, {x, -1, 10}] produces a plot while Plot[xe^x, {x, -1, 10}] only draws axes. Can someone please explain why there is no ...
  • 43
0 votes
0 answers
35 views

How get this kind of group opener?

Some notebooks of mine have Section (and Subsection) cells formatted like the following, so that clicking on the icon to the right of the Section's title opens the entire group of cells in that ...
  • 11.6k
2 votes
2 answers
36 views

Remove sublists with duplicate elements within

I have this list DeleteDuplicates[Sort[#] & /@ Tuples[Range[4], 3]] which gives me {{1, 1, 1}, {1, 1, 2}, {1, 1, 3}, {1, 1, 4}, {1, 2, 2}, {1, 2, 3}, {1, 2, 4},...
1 vote
1 answer
42 views

FunctionPoles with arbitrary undefined function

Good day everyone. I have very simple question about behaviour of the functions FunctionPoles, FunctionMeromorphic e.t.c. Can these functions work properly with undefined functions? For example when I ...
  • 23
2 votes
1 answer
36 views

PlotLegends does not work with StringPadRight?

I'm trying to create a plot legend where the rows contains multiple items, and those items have the same width, so that they appears to be in column. It should work with String Pad Right but for some ...
0 votes
0 answers
40 views

Drift-diffusion ODEs with two boundary conditions

I am trying to solve drift-diffusion equatons (Poisson's equation, continuity equations for electrons and holes and Kirchhoff's equation) for a reversely biased diode in a stationary state (no time ...
  • 53
4 votes
3 answers
80 views

Adjust graphs inside GraphicsRow to be the same scale?

I want to draw a picture with GraphicsRow function in Mathematica. A simple example shows as follows ...
  • 229
-1 votes
0 answers
28 views

General solution for X in trapezoid 90 degree [closed]

Could you please help to find a general solution for X, no matter if a > b or a < b ? []https://i.stack.imgur.com/dDUEf.png[1] Thank you!
1 vote
1 answer
68 views

How to place several plots side by side?

I want to place multiple MatrixPlot results side by side. Here's the example code: ...
  • 229
3 votes
2 answers
49 views

Adjusting spacing of one row in LineLegend?

Background I have the following plot: ...
0 votes
0 answers
16 views

When turning expressions to input strings, is it possible to make scientific notations of large integers stay unchanged?

...
  • 8,544
0 votes
1 answer
52 views

How to switch Tan[x] for Sin[x]/Cos[x] without Mathematica changing the latter for the former?

When I ask Mathematica to do this: (Sin[2 x] - Tan[2 x])/x^3 /. Tan[x_] -> Sin[x]/Cos[x] It makes no change because Mathematica interprets ...
  • 5,061
0 votes
1 answer
16 views

Nested RowBox in MakeExpression reports error when I define my own curl operator, but the single RowBox in MakeExpression works well

I want to define my own vector notation so that the input \[Del] \[Cross] a outputs curl[a] while the ...
  • 1
4 votes
2 answers
99 views

How to wrap text of large headings in dataset?

I am trying to achieve the following effect produced in Excel in Wolfram Dataset: The following attempt doesn't work: ...
  • 8,707
1 vote
0 answers
18 views

Periodogram and frequency

On the x axis of periodogram, one should have either a period or frequency. What frequency is used in Periodogram --- angular or ...
  • 3,486
0 votes
1 answer
61 views

Is it possible to ask Mathematica to find those points $(x,y)$ at which the given function may reach its global/local extrema?

I have this two-variable function $f(x,y)$ for {x,-Pi,Pi} and {y,-Pi,Pi} in which $\{a,b,c\}$ are real parameters (can be ...
  • 93
0 votes
0 answers
25 views

Kernel crash during Interpolation

I have a kinda large code of a solver, and after somewhat random amount of iterations it causes Kernel to shutdown with a "pop" sound and no messages. I tracked the exact line that caused it,...
0 votes
0 answers
26 views

Plotting a PDF with discrete non-integer values

I can plot the PDF of a continuous distribution like so d0 = NormalDistribution[0, 1] Plot[PDF[d0, x], {x, -3, 3}] I can plot the PDF of a discrete distribution ...
  • 111
2 votes
2 answers
59 views

Access item of multidimensional table

I am working on an program that uses a parametric dimensions table created like this: t = Table @@ Prepend[{2, 3, 4, 5}, 0] No problem to get the value of a given ...
1 vote
1 answer
45 views

A 3-dimensional principal value integral [closed]

I am trying to find a principal value integral of the following form in Mathematica. $f(z)$ is a smooth function. The problem is that Mathematica is very slow in this computation. $\int_1^2 dx\int_1^3 ...
3 votes
2 answers
190 views

How to Vectorize this Function?

I have been puzzling over how to vectorize the following function: ...
  • 339
0 votes
0 answers
30 views

PDE Problem: NDsolve give the results inconsistent with the initial state [duplicate]

We are solving the non-linear PDE, like this ...
  • 177
1 vote
1 answer
41 views

How to concatenate an array of matrices?

When trying to concatenate matrices i usually use Join. But having the matrices in an array it gets tricky. As an example: ...
  • 117
0 votes
0 answers
37 views

Fitting an exponential system

Consider the following system over a periodic array, where $1\leq j\leq n$, $$ y_j= \sum_{k=0}^m \frac{e^{-\sum_{|i|\leq k}(k-|i|)x_{j+i}}-e^{-\sum_{|i|\leq k}(k+1-|i|)x_{j+i}}}{\sum_{|i|\leq k} x_{j+...
  • 4,362
0 votes
0 answers
30 views

How to reassign variable value? [closed]

I wrote this code for metric ={{1,0,0},{0,1,0},{0,0,1}} but then changed the metric. However, the value of the metric in christ ...
0 votes
1 answer
19 views

AceGen/AceFEM: Divergence in a term, that should be equal to zero

I have a problem concerning the order of the evaluation of the AceFEM parameters. My AceGen Element contains, among many others, an expression of the form B (aa - bb/(cc Exp[dd w^2] + ff)) with B, aa, ...
1 vote
1 answer
40 views

Understanding Distribute when applied with a user defined function

I would expect this F[x_] := Module[{aux = x}, aux = X]; {a + b + c, e+ f} // Map[Distribute@*F] to yield {3X, 2X} instead, the function is not distributed ...
  • 670
0 votes
1 answer
33 views

Doing algebra with differential operators

I'm doing some work on stochastic processes, where I use random functions which are defined by their properties over averages, i.e $$\langle f(t) \rangle =0 \\ \langle f(t) f(t')\rangle = \alpha(x,y) ...
  • 1
0 votes
0 answers
28 views

Notebook contents replaced with Null

I opened a notebook that I had recently made only to discover that all cells except the first one (an initialization cell) have been removed and all titles/subtitles except the first one have been ...
  • 1,216
1 vote
1 answer
32 views

Using Replace with

I have an expression expr=Derivative[1][A][\[Zeta]] + Derivative[2][A][\[Zeta]] + Derivative[3][A][\[Zeta]] + Derivative[4][A][\[Zeta]] I want to replace ...
1 vote
1 answer
58 views

Pull out numerical factors from the argument

I'm trying to define a function that is distributive over Plus and pulls out the numerical factors from the argument: ...
  • 670
0 votes
0 answers
21 views

Help with Mathematica Documentation Installation Error

I've encountered an error while installing the documentation for Mathematica, as displayed in the image below. Although the file that the software is asking for is clearly visible and unrestricted, ...
  • 2,822
0 votes
3 answers
89 views

How to plot the solutions of nonlinear equations with a parameter varies?

I want to get the solutions of equations with a parameter. But I cannot get a closed-form expressions of x、y. I just want to show how x、y vary with the parameter [Delta]. If i assign values to [Delta],...
3 votes
2 answers
94 views

Efficient method (maybe parallel method) to calculate a 256$\times$256 matrix?

I want to calculate a matrix of shape 256$\times$256 as follows ...
  • 229
2 votes
3 answers
184 views

How to verify the ODE for Airy function with Mathematica?

I believe that the function AiryAi[x] satisfies the ODE y''[x]-x*y[x]==0 (see Encyclopedia of Mathematics and Wiki and Weisstein,...
  • 21.1k
4 votes
1 answer
32 views

TimelinePlot with many intervals becomes white

This is an example of a TimelinePlot with 100 intervals: TimelinePlot[Table[Interval[{0, 1}], {30}], PerformanceGoal -> "Speed"] If we ...
6 votes
1 answer
119 views

Distinguish three fraction forms (feature stronger than Hold)

This question can not be typed easily, using mathematica stackexchange interface. So here is a GIF file : My question is : Can we construct a function f whose ...
  • 3,623
1 vote
0 answers
19 views

Incorrect result for parallel run to calculate a Do loop? [closed]

I want to calculate the following Do loop Clear["Global`*"]; pmat = ConstantArray[0, {4, 4}]; ParallelDo[pmat[[i, j]] = i*j, {i, 1, 4}, {j, 1, 4}]; pmat ...
  • 229
-1 votes
0 answers
18 views

Mathematica plot function of this [migrated]

Descriptive function of motion of a rigid rod around an axis and, by analogy, around a cylinder and the volume "swept" from it I kindly ask for your help for the "rust" that, after ...
  • 1
1 vote
1 answer
43 views

Fourier series solution for Laplace equation in polar coordinates results in Power::infy and Infinity::indet

Definition of function f f[θ_] = 1 + Cos[2 θ] + Sin[3 θ] Plot[f[θ], {θ, 0, 2 π}] Computation of the Fourier coefficients ...
0 votes
1 answer
38 views

`Periodogram` returning only 1/0 error

I have a large dataset and would like to get a Periodogram (I saved the data as CloudObject): ...
  • 3,486
3 votes
2 answers
108 views

Partition of lists with specified elements

I have an array like this and want to split it into sublists. It should contain the first element "Res" without curly braces and the one sublist starts from 2 to the 9th column the 3rd ...
  • 73
3 votes
2 answers
101 views

Cube inscribed into a dipyramid

Starting with code nicely done at this post, I have been able to produce this graphic Several problems remain: For Dipyramid, there is a superfluous line through the center of the cube. There are two ...
  • 714
0 votes
0 answers
38 views

Creating Common Color Scheme and Contour Intervals Across Different Data Sets

With the help of @JimB in Comparing different ListPlot3D outputs between different data sets I have a code that will plot the difference between two mesh maps (shown in the code below). However, I ...
1 vote
0 answers
46 views

Does anyone have any Mathematica code for rainflow counting for fatigue and damage equivalent load anlaysis?

‘Rainflow Counting’ is a method to determine the number of fatigue cycles present in a load-time history. See https://en.wikipedia.org/wiki/Rainflow-counting_algorithm There is a MatLab function that ...
  • 63
1 vote
0 answers
77 views

Solution to a 2D Schrödinger equation

I am trying to solve a 2D Schrödinger equation with a complicated non-separable potential $V(z,\rho)$, $$ \nabla^{2}\Psi(z,\rho) +2(E_{0}-V(z,\rho))\Psi(z,\rho),$$ where $E_{0}$is the energy, $\hbar=m=...
  • 11
0 votes
0 answers
44 views

Stuck in parallel computing [closed]

I'm running ParallelTable using Mathematica, and it always stuck! The following errors: LinkObject::linkd: Unable to communicate with closed link LinkObject["/...
  • 31
0 votes
0 answers
36 views

Cubic Bezier Curve is not plotting correctly in Wolfram alpha [closed]

I'm trying to plot a cubic bezier curve to understand if the equation is correct. I have the following equation, which has set p0..p3 to 0.5, which should result in a linear curve. ...
  • 101
2 votes
1 answer
80 views

Partion of lists

I have a list like this and want to split it into three sublists. One should contain only the first element the 2nd should contain 8 elements starting from 1.944 to 11 and the third should start from ...
  • 73
1 vote
1 answer
41 views

Mesh as list of seperated lines

Startingpoint is the following 3D plot: ...

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