2
votes
4answers
954 views

I need F(x,y) = xy (not x*y) e.g. x= 1, y =2 so F(x,y) = 12 [closed]

I just need F(x,y) that give me e.g. x= 1, y =2 so F(x,y) = 12 Is that possible. I tried Google but not able to find a ...
1
vote
1answer
81 views

Solving differential equation but keeping showing running

I am trying to solve this differential equation, see the command below. But the cell keeps showing that it is running without giving any answer for a very long time. Eventually I had to abort it. Does ...
1
vote
1answer
98 views

How do I display graphics in the Wolfram Language kernel? [duplicate]

I'm unable to view graphics output when working directly with the kernel from a terminal window. How do I display graphics when working that way?
0
votes
1answer
47 views

Part of longer code has an error - how can I debug?

Please can someone help me locate the problem? ...
1
vote
1answer
246 views

Efficient algorithm to generate a basis for exact diagonalization

The problem is described as follows: I need to generate a basis(matrix) in lexicographic order. For two different basis vector $\{n_1,n_2,\cdots,n_M\}$ and $\{t_1,t_2,\cdots,t_M\}$, there must exist ...
0
votes
1answer
116 views

Can't get a plot from piecewise parametric function [closed]

I can't seem get a 3D plot from r[t]. Any suggestions? ...
2
votes
1answer
92 views

Change Tensor Product symbol for aesthetically pleasing output

I'm trying to find a way of keeping an ordered list of subscripted integers which can be outputted in an aesthetically pleasing way to make analysis easier. The idea is to have a list of numbers that ...
7
votes
2answers
210 views

Speed and the MapThread function

Can anyone help explain why MapThread is so slow in this simple case? ...
8
votes
1answer
209 views

Trouble with polynomial multiplication

Bug introduced in 10.1.0 and fixed in 10.4.0 ...
8
votes
5answers
273 views

Use different markers/colors in logarithmic plot depending on sign

Suppose you have the dataset xData = Table[i, {i, 1, 30}]; yData = RandomReal[{0.995, 1.005}, 30]; and want to plot the difference of ...
4
votes
0answers
44 views

How to make a button that allow me to control a Manipulate module? [duplicate]

I'm trying to use button that allow me to control a manipulate module. Here's what I did now, it's really simple: ...
0
votes
1answer
136 views

KdV equation - wavebreaking and Galerkin method

I want to show how a wave given by the initial condition: $$ \begin{equation*} \begin{split} u(x, 0) = \left\{\def\arraystretch{1.2}% \begin{array}{@{}c@{\quad}l@{}} 1 - x^2 & \text{for ...
7
votes
0answers
86 views

NotebookWrite a Cell with WholeCellGroupOpener option [duplicate]

Why NotebookWrite[ EvaluationNotebook[], Cell["ZZ", "Section", WholeCellGroupOpener -> True] ] produces: ...
3
votes
1answer
139 views

Intra day data with TradingChart

I am trying to use TradingChart to display some intra day data (60 s. resolution). Is there a way to modify the time displayed when moving the mouse over the data. The default setting (see top left of ...
3
votes
3answers
162 views

NDSolve and Plotting

So I am having an issue using NDSolve and plotting the function. So I have two different NDSolve calls in my plotting function. ...
1
vote
1answer
131 views

How to make a StreamPlot with three variables and two expressions

I'm trying to make a StreamPlot in Mathematica with three variables. I already have two variables, x and y, that make an ellipse via StreamPlot[{-y,x}] but I ...
26
votes
3answers
575 views

Place a small gap between axes and plot?

See for example this picture produced with R: You can see there is a small white space between the x-axis and the y-axis, so that the axes do not cross. How can I do this with Mathematica, for a ...
2
votes
0answers
98 views

When does Mathematica automatically use dispatch tables for function evaluation? [closed]

I've read the documentation for Dispatch, and it says: Lists of rules produced by assignments made with = and := are automatically optimized with dispatch ...
12
votes
1answer
2k views

Mathematica vs Python - how does it compare to Python's scientific computing suite?

Python's family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica's functionalities, but with production level and open-source code using the ...
9
votes
1answer
150 views

Naming a pattern changes outcome in StringCases[]

s = "1 2 "; StringCases[s, (n : NumberString ~~ " ") .. ] StringCases[s, (NumberString ~~ " ") .. ] yields ...
9
votes
2answers
630 views

How to draw a protractor in Mathematica

I would like to draw a protractor with Mathematica. I hope this is a fun question. Here is some start codes I tried: ...
5
votes
2answers
161 views

Speed up image coloring with ReplaceImageValue

I have about 200000 rgb-images of such format (2160*577 pixels): I want to colorize in each image some parts in white color: ...
1
vote
0answers
57 views

Defining a function with a subscripted head

How can I define a function with subscript? Forexample: f_alpha[x] = 2*x
8
votes
2answers
175 views

How to write a custom ParallelTable command that monitors progress automatically

I am using a lot of ParallelTable and want to avoid wrapping it in a Monitor call each time. Since each of the calls inside ParallelTable will already consume considerable time, I do not mind the ...
3
votes
2answers
94 views

Switching between solutions of a fourth order polynomial

I am plotting the roots of a fourth-order polynomial as a function of some parameter $r$ with the following code: ...
2
votes
1answer
91 views

Tab in Input cell

Why is it impossible to use tab to indent e.g. an inline comment i.e. (* ... *) in an Input cell? However, I have seen that it is possible, if I use Cell>ConvertTo>TextDisplay. The cell remains ...
3
votes
2answers
170 views

Format google places JSON output

I'm have some trouble formatting the Output of a 'Import' request. I get this as a return of a google places API request: ...
2
votes
1answer
81 views

Type declaration for list arguments

How can I make f[n_Integer]=2*n valid for a list of integers? For example: f[nlist_Integer] := 2*nlist[[1]] does not work ...
-1
votes
1answer
81 views

rolling a sum of 6 or less, on 3 dice [closed]

What is the probability of rolling a sum of 6 or less when rolling 3 dice(six sided) at once. I understand how to get the probability of rolling the sum of 6 but of 6 or less confuses me.
3
votes
1answer
56 views

Behavior of code changes after a palette is installed

Please consider the toy code here: ...
2
votes
2answers
149 views

How can I partially evaluate a function?

I have a multivariable function, from which I'd like to define a marginalization: f(a,b,c,d,...,z) ---> g(a,1,c,d,...,z) Generally, g will have fewer argument than f, possibly none (full ...
0
votes
0answers
40 views

Start counting pages from 3rd page

How do I start page numbering from page number x? I've tried PrintingStartingPageNumber, but setting it to -2 gives me negative page numbers at first 2.
3
votes
2answers
103 views

How to show and hide text by a button

I'm trying to implement a button that can show and hide output text in a panel/tab, but I can't find a specific command to do that. I tried StringReplace, but it doesn't work for me.
0
votes
1answer
64 views

Custom headers - RunningText bug?

I'm trying to get MMA ready for writing papers and I'm almost there. At first it looked like there was plenty of space for customization with custom headers and footers, but then it turned out that I ...
3
votes
1answer
86 views

Duotone plots with cyan and black

What's the typical way to make Mathematica plots use purely cyan and black? Maybe there's a fairly standard method, since publishers often require this? It also seems like some plot types take ...
0
votes
1answer
112 views

How do I store Eigenvalues of a 14*14 matrix in a For loop into an array and then plot that array? [closed]

I have a matrix 14*14 that is dependent on parameter a. How can I plot eigenvalues of the matrix according to varous values of a?
2
votes
5answers
234 views

Add values from a list, at positions from a list, to a matrix

I'm investigating matrix assembly and one of the things I'm trying to do is add specific values to a larger matrix based on a list which is essentially defining connectivity of nodes. For example: ...
2
votes
0answers
116 views

Different solutions for seemingly same Integral

I want to evaluate the following integral: $$\int_{\left(1-\sqrt{a}\right)^{2}}^{\left(1+\sqrt{a}\right)^{2}} \frac{1}{2\pi ...
4
votes
1answer
118 views

Substituting ParametricNDSolve for NDSolve

This is my first post so let me know if I need to format things differently. I have been using NDSolve for most problems which optimize parameters for ODEs. I believe that ParametricNDSolve would be ...
22
votes
3answers
1k views

How to plot an emission spectrum?

If I have a list of data with various wavelengths in nanometers, how would I plot them on a graph so it looks like this: So far I have managed to plot a spectrum in ...
0
votes
0answers
63 views

Finding when a ODE returns to starting position

I am trying to discover when these ODE return to their start position. I am using coordinates that have a periodicity of {Pi/2, 2Pi, 2Pi}. To accomplish this I have had to use mod. The ODE are ...
2
votes
3answers
155 views

How should I debug a failed Manipulate of RegionPlot?

I am trying to build a package that will display a sector of an ellipse where the angle is taken from a focus of the ellipse rather than from the center. The code seems to work fine when called with ...
1
vote
1answer
72 views

How-to implement iteration over a result of an iteration in a functional way

I have a pure function f:= #1 * #2 * #3 &; Which I can invoke in a following way: f[#,2,3]& /@ {1,2,3} Which ...
0
votes
0answers
94 views

PolyLog does not simplify

How come mathematica can not simplify a simple expression involving the PolyLog function? An example is: You know that ...
2
votes
0answers
67 views

Export on local machine results of a parallel computation using remote kernels [duplicate]

I've got a long calculus to do with Mathematica. I've Parallelized the code using local kernels and remote kernels. I'm using a ParallelDo loop with an ...
0
votes
0answers
130 views

How to optimize a cost function which involve the solution of a ODE system using the NMinmize?

I have created a cost function, the value of which depends on the solution of a ODE (ordinary differential equation). The parameters of the ODE are not determined, and my goal is to determine them ...
0
votes
1answer
105 views

Draw a number of rectangles from list of coordinates [closed]

I'm new to Mathematica and this is also my first post here. Now for the question: I try to let Mathematica draw a number of rectangles from lists of coordinates. Unfortunately it only works when I ...
2
votes
1answer
131 views

Contours aren't aligned with frame ticks in ContourPlot

Because of the problem described in BarLegend can't make spaced contours when contours number>11, I decided to brew my homemade spaced-contours-barlegend. After some trials I get something like ...
2
votes
1answer
85 views

Cloud deployment of a Manipulate expression

I would like to deploy the following Manipulate function, which works in a Notebook: ...

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