4
votes
1answer
289 views

Running a package automatically when it's saved

When developing some new code (eg. a function to analyse something) I usually make a .m and .nb file. The code goes in to .m is then called from the .nb. But sometimes I forget to run the package ...
4
votes
3answers
309 views

How to cancel floating point factors?

I am currently having problems with some floating points. I have a function, which gives as an intermediate result (for example) ...
4
votes
2answers
257 views

How to close the front end so I can clear all Global variables?

I first thought that doing Quit[] in a cell, or Evaluation->Quit kernel, is supposed to remove all Global variables, but I have a case where this is not happening, then I read that there is a command ...
3
votes
1answer
76 views

Import iTunes xml data and convert it into a dataset or table

I have an xml file with song data from iTunes (https://dl.dropboxusercontent.com/u/1012958/iTunes%20Library.xml) and I'd like to import it to Mathematica to do some statistics. I get an XMLObject like ...
3
votes
2answers
147 views

Problem with Poincare section

these are equations for some double oscillators: $x'(t)=p, p'(t)=-x-3y, y'(t)=q, q'(t)=-y-3x$ I would like to plot the Poincare section for collection of $(y,q)$ when $x=0$ and $x'(t)>0$ (or for ...
3
votes
1answer
93 views

Custom operators; custom pattern matching with pure functions

What I'm trying to achieve in Mathematica is the creation of a binary operator whose operands are both pure functions over the natural numbers. The result of the operator should be another pure ...
3
votes
1answer
218 views

Need help with C Code Generator

I'm trying to use the Mathematica C Code Generator package to generate code that is to be included in a web application by a developer. I don't know any C, and this seems to be the only way to ...
3
votes
1answer
109 views

Inheritance in Mathematica using pattern matching on UpValues

Edit: I think in my original post, I missed emphasizing the main point. This is mainly a pattern matching question. If you're interested in the 'why' of this question, please read the original post ...
3
votes
0answers
118 views

Do a gauge transformation for a Chern-Simons theory?

Suppose we have the following Lagrangian density: $$ L=\epsilon^{\mu\nu\rho}\big(\sum_a A^a_{\mu}(x) \partial_\nu A^a_{\rho}(x)-\sum_{a,b,c}\frac{1}{3} f^{bca} A^a_{\mu}(x) A^b_{\nu}(x) ...
3
votes
1answer
213 views

How to speed up Manipulate with Graphics3D

How do I speed up the Manipulate of the Graphics3D objects here? It is currently painfully slow, and I'm at a loss. I have reviewed many other posts and implemented what I could based on them, but it ...
3
votes
1answer
210 views

ImageSize as absolute (metric) value

I have wondered more and more often lately how the size of an image is handled when displayed or exported. The documentation implies that the via ImageSize the ...
3
votes
3answers
290 views

Generating a graph where vertices correspond to points in an integer lattice and edges connect points less than a threshold distance apart

I'd like to automatically generate a graph where vertices correspond to (and have the coordinates of) points in an $A \times B$ integer lattice, and a graph is generated by connected vertices within a ...
3
votes
2answers
121 views

How to make the computer consider two numbers equal up to a certain precision

My problem is that I have a matrix A and the computer says is not Hermitian (self-adjoint). Then I check which elements make A ...
3
votes
3answers
183 views

What is the formula for this numerical series?

I'm developing a questions game. My goal is that the score for each correct answer will increase as the user answers more questions. Initially there are 15 points for each correct answer. Every 4 ...
3
votes
1answer
294 views

How can I get Mathematica to recognize equality of symbolic matrix expressions?

I have two matrix expressions: X.Transpose[T].Transpose[X] and X.T.Transpose[X] I want Mathematica to recognize that ...
3
votes
3answers
271 views

ArrayPlot and non-integer PlotRange

There seems to weird bug regarding non-integer PlotRange in ArrayPlot. For example... ...
3
votes
1answer
269 views

Exception/Error handling using returns codes

There is good explanation available for error handling on this and similar links. Here there is information on handling inappropriate input arguments and handling unprocessed functions using ...
3
votes
1answer
112 views

How can I export definitions of several symbols to a single file?

the problem related to this question What I want to do is to Export definition of several symbol into a single file. The reason I choose ...
3
votes
2answers
531 views

NDSolve: Normalizing at every step

Suppose I have an transport equation with an initial conditions: ...
3
votes
1answer
514 views

Getting over Mathematica Bar Chart Limitations….

I am trying to create a pareto chart for some non technical folks and having the hardest time formatting it correctly… Here’s my sample code: ...
3
votes
1answer
380 views

Exporting a Video of a Simulation of Pendulum Motion

In a series of previous questions, I asked how to solve a series of differential equations describing a series of coupled pendulums, and then how to plot this data by coloring the different pendulums. ...
3
votes
1answer
662 views

Non-commutative algebra

I'm constantly dealing with non-commutative algebras. ** is inbuilt, non-commutative and associative. That's good :-) But it is not distributive. Rats. ...
3
votes
2answers
255 views

How can I fill an entire Building with transparent points? [duplicate]

I am posting the same code found at an earlier question, although the concept here is totally different. The following code corresponds to a building-shaped structure. ...
3
votes
2answers
135 views

Get DownValues that do not involve patterns?

Say I have a function with a few definitions that also implements memoization: f[x_] := f[x] = x^2 f[x_, y_] := f[x, y] = x^2 + y^2 I then apply the function to ...
3
votes
1answer
99 views

Why is MenuCommandKey not working in my stylesheet?

Here is the cell style data for my custom version of Section: ...
3
votes
2answers
203 views

How can I get Mathematica to include size information in exported SVG?

When I use Export to export graphics in SVG format, the exported file contains no width ...
3
votes
4answers
352 views

Make function return unevaluated equation

I have made this function which outputs the equation of a nth degree polynomial: ...
3
votes
2answers
459 views

How to model Macroeconomic dynamics?

I am rather new to Mathematica and I wanted to see if I could get some help with the following. I am trying to generate a model of macroeconomic indicators defined by the following functions, but I ...
3
votes
2answers
218 views

Showing a forest with root of the trees on the top

I have a Graph object that contains a forest with directed trees. I want to draw the forest such that the root of the trees are on the top and the leaves are on the bottom. If I use the following line ...
3
votes
3answers
2k views

Map w/ multiple arguments [duplicate]

Possible Duplicate: How do I use Map for a function with two arguments? If I have a function: F[x_,y_,z_]:=x*y*z and I want to call it with several ...
2
votes
2answers
246 views

Tweaking Solve for systems of polynomial equations

I am trying to solve the following system of $6$ quadratic equations in $6$ variables: ...
2
votes
1answer
143 views

How can I exhibit the evaluation of formulas in a Mathcad-like way?

How can I create a function F that works like this: x = 2 f1 = x^2 + 3 f2=x+5 F[f1] x^2 + 3 = 2^2 + 3 = 7 ...
2
votes
2answers
273 views

How can I build a GraphicsGrid of arbitrary size?

This is actually a very simple scenario, in order to make simpler this question Part I. Consider the following piece of Mathematica code ...
2
votes
1answer
256 views

Mesh inside Plot legend

I have a plot for which I would like to create an legend that is black and white printer friendly. I have seen Jen's legendmaker but I don't know how to adapt it. I need help in making the legend for ...
2
votes
1answer
225 views

Including two ListLinePlots in a 3D graphic

I have two lists of data which I am plotting on two ListLinePlots. I would like to have these two plots appear perpendicular to each other on a 3D graphic. I have ...
2
votes
0answers
547 views

ParametricNDSolveValue or NDSolve + fitting

I have been trying to find the value for the parameter kestim that yields the best fit of a model to some data points. datac has ...
2
votes
2answers
486 views

Dynamically choosing which Manipulate controls to use

I have some stuff I would like to manipulate, using two different kinds of control, one at a time, using another variable as a switch. These controls are similar in principle to ...
2
votes
1answer
735 views

Export Animate command to MOV video

I'm trying to export a rather complex Animate command into a full-HD resolution video, but having no success so far. The animation has around 520 frames (the number ...
2
votes
2answers
424 views

MathLink and CDF

So far I have read that some things are not supported in CDFs. Istvan-zachar mentioned very useful things in his post. Unfortunately he mentioned that MathLink operations, including J/Link and ...
2
votes
1answer
153 views

How to set PageWidth when using PutAppend to append expressions to a file?

Do[ PutAppend[Table[i, {RandomInteger[100]}], "./file.m"], {i, 100} ] I'd like each inner list to always appear on the same line, but not automatically ...
1
vote
2answers
150 views

3D Contour Plot parts of sphere with gradient less than 0, equal to 0 and more than 0

I want to plot only parts of the sphere of radius 1 where the gradient $\frac{\partial z}{\partial x}$ is < 0, = 0 and > 0. The full sphere is given by: ...
1
vote
2answers
62 views

Unintentional function memoisation via Dynamic

I needed to display edge labels of a graph in a way that allows the edge labels to be moved. ...
1
vote
2answers
481 views

Research positions of lists of varying size

I'm new to the site and I am French, so I ask your indulgence for my future mistakes in English. I would like to optimise the following code : ...
1
vote
3answers
405 views

Generate random points in a region with higher probability in a sub-region

I am trying to generate random samples of points in the unit square in such a way that points inside a given circle are twice as likely to be selected as points outside that circle. I tried to ...
1
vote
2answers
334 views

EdgeRenderingFunction question

(Edit 1 : I added this paragraph after the original post, for context) Some context for this question can be found in another post (Problem with EdgeRenderingFunction), which however may be taken ...
1
vote
2answers
509 views

How can I get even steps on x and y axes in a plot?

I'm plotting the shortest distance from a point to a line using the following code ...
1
vote
2answers
926 views

Can I improve the importing speed of Excel data?

I have data in an Excel spreadsheet that has 4 rows and 1,000 columns. I am using Import as follows: ...
1
vote
1answer
162 views

How can I create some shorthand notation for a custom control?

Per this question, I have created a custom graphical control object which evaluates to a list of values. I would like to be able to create such an object quickly, rather than typing some command, ...
1
vote
3answers
1k views

How do I plot x[t] vs. x'[t] (where x[t] and x'[t] are solutions to NDSolve)?

I have a differential equation which I solved using NDSolve. I can easily plot x[t] vs. t, x'[t] vs. t, but.... how do I plot x[t] vs. x'[t]? I tried using the Evaluate function to simplify things, ...
1
vote
4answers
3k views

Creating a data1 versus data2 plot?

I have a table of data with multiple rows and columns, and I have to make a versus data table using two of these columns. Essentially, I have to set one column of data (column 3) as the y-axis and ...

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