# All Questions

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

Please can someone help me locate the problem? ...
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 ...
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? ...
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 ...
210 views

### Speed and the MapThread function

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

### Trouble with polynomial multiplication

Bug introduced in 10.1.0 and fixed in 10.4.0 ...
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 ...
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: ...
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### 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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...