1
vote
1answer
218 views

List comparison in constraints for Minimize

I am trying to solve an optimization problem, a simplified version of which is as follows: ...
3
votes
0answers
95 views

shortest paths in probabilistically weighted edges? [duplicate]

I understand Mathematica can find shortest paths. However, is it also able to find the most probable paths? I mean this is a case where edges are given probabilistic wights (from 0 to 1) and the most ...
3
votes
1answer
191 views

Exploiting self-adjointness when changing basis

I am using Mathematica to analyze a real, self-adjoint matrix $H$ of the size $32 \times 32$, which comes from a physics problem. In the picture there is also a matrix $Q$ which commutes with $H$. I ...
2
votes
0answers
136 views

Nest for large value of n

I am working on a problem to find the Feigenbaum constant. In this problem I have to get $f^{2^n}(1/2)$ with $f(x) = kx(1-x)$. I use Nest to get $f^{2^n}(1/2)$ but ...
0
votes
3answers
240 views

Conjugate and simplify

I want to get a cosine from taking the real part of a complex exponential: $cos(x) = Re(exp(i x))$. What I do in Mathematica is ...
1
vote
2answers
357 views

Import large amount of data with time stamps

I have a large data file (150 000 lines) which I want to import in Mathematica. The first few lines look like this ...
2
votes
0answers
111 views

Significant platform-dependent efficiency when importing data?

I'm curious, as I understand that answer this way: If you are using a Linux derivative or something like cygwin on Windows, then this is an efficient solution for reading only the third field ...
2
votes
1answer
142 views

Solving a system of equations

Mathematica doesn't want to solve my exact system with 3 equations and 3 variables. ...
1
vote
1answer
135 views

How can I stop DiscreteMarkovProcess[] from relabeling vertices?

I'm attempting to calculate the mean first passage time between two vertices, $v_1$ and $v_2$, provided some undirected graph $G$. However, I noticed that running the following script: ...
7
votes
2answers
325 views

Problem with NIntegrate when WorkingPrecision is specified

I am trying to evaluate this integral numerically: $$ \int_0^{\infty } m \exp (-m) J_1(m){}^2 \, dm $$ Everything is OK when only the integration method is specified: ...
1
vote
1answer
307 views

List plot 3D not showing correct data

I have a list of values of the form {{a_1,b_1,c_1},{a_2,b_2,c_2}...} where a goes from 0 to 30, ...
4
votes
2answers
443 views

Efficient drawing of convex polyhedron given a set of points [duplicate]

I have a set of points in the 3D space and I want to draw the bounding convex polyhedron of those points. A very naïve solution would be to draw a triangle between every three points: ...
3
votes
3answers
317 views

Mathematica not able to confirm its own solution to differential equation

I type the following into Mathematica: DSolve[q''[x] + 2 x/(x^2 - 1) q'[x] - 4*q[x]/(x^2 - 1) == 0, q[x], x] It gives me the result ...
1
vote
0answers
83 views

What algorithm is Mathematica using for FirstPassageTimeDistribution[]?

What algorithm is Mathematica 9 using for FirstPassageTimeDistribution[]? Is it attempting to use PseudoInverse[] on the ...
19
votes
1answer
812 views

Peirce's quincuncial projection

The Peirce quincuncial projection is the cartographic projection of a sphere onto a square. In short, I would like to see it implemented in Mathematica. Here is my code: ...
2
votes
1answer
754 views

How do you draw a straight line with PolarPlot?

I can't figure how to draw a line with PolarPlot. A vertical line through a is $r \cos(\theta) = a$, so ...
1
vote
3answers
177 views

iterate method to find roots

This code gives the roots (lambda-values) of eq1 by using iteration. ...
8
votes
2answers
970 views

Viewing Mathematica Demonstrations Project Code

I hope I am going insane and the I'm not seeing the snake about to bite me... How does one view the code in the demonstration projects that one can download from wolfram.com? It seems like all of ...
1
vote
2answers
228 views

Efficient Data Entry / Manipulation with Many Datasets

I currently have a simple task of graphing many different datasets (26 here, with many different instances where I'll need to do, say, 26 different ones from the same template). I'm trying to ...
8
votes
2answers
581 views

How do I create an ellipse bubble chart?

I have some data that I would like to plot as a bubble chart. The data is formatted as {{val1_mean,val1_sd,val2_mean,val2_sd},{val1_mean,......}}. What I would like to do is plot a bubble chart where ...
5
votes
4answers
960 views

Arcs of rotation for angles

How can I draw trigonometric angles of any radian measure associated with the unit circle, complete with the x-axis and y-axis? How can I draw arcs of rotation inside positive or negative angles? Is ...
5
votes
0answers
497 views

Export matrix to $\LaTeX$ with style

Is it possible to export a matrix to $\LaTeX$ with style? For example this code will create a matrix with equal spacing matrix and with background colors in some cell, is it possible to export that ...
2
votes
2answers
1k views

Importing several huge files with headers & footers

having here several files in ASCII format http://ge.tt/91rv0Jf/v/0 I want to import, while removing headers and footers and then join the several lists. ...
3
votes
2answers
269 views

How to rewrite this function to be faster: Find sub-matrixes of boolean board which imply a given boolean pattern

I have Boolean matrix A (called "board") and Boolean matrix B with smaller dimensions (called "pattern"). I am trying to find sub-matrixes C of A such that C has same dimensions as B, and ...
3
votes
1answer
132 views

Defining an Implies operation that works for Boolean matrices

I have two Boolean matrices, that both have dimensions m x n. I want to create a function TableImplies, which would return True ...
2
votes
1answer
249 views

Custom (Frame)Ticks fail when using Mathematica's script engine

I want to define my own ticks in a DateListPlot. It works quite well when I use the code in a Mathematica Notebook but breaks somehow when using it via ...
1
vote
3answers
106 views

Edit AxesLabel from an existing plot

I have a really complex function that takes a few hours to plot as a function of a parameter. Few days later I realised that I named the axes wrong. Is there an easy way to edit the AxesLabels without ...
2
votes
1answer
327 views

How to integrate ParametricNDSolve solution with respect to a parameter?

I have just upgraded to the new version of Mathematica because of its new built-in ParametricNDSolve function. I need to solve a first-order non-linear ordinary ...
3
votes
4answers
386 views

Problem with WhenEvent

I am trying to add a time dependent fraction to a parameter in NDSolve, i.e. when 10 < t< 20, add ...
0
votes
0answers
35 views

Plot derivative of integral with changing limits [duplicate]

My code is: Plot[D[Integrate[E^(t*(-x^2)),{x,t+2,t^2}],t],{t,-2,3}]. The errors/warnings are: ...
0
votes
2answers
798 views

Network database access - How do I connect to a remote database?

I am able to connect to a specific MS Access Database when it is on the same Windows computer as Mathematica via the command ...
1
vote
2answers
192 views

Manipulate keeps replaying the animation non-stop

I made a notebook with the following code, but for some reason when I evaluate it it keeps replaying repeatedly. What is causing this? Thanks. ...
11
votes
2answers
2k views

Graphics3D: Finding intersection of 3d objects and lines

I found these two nice links 1) intersecting graphics 2) Implementation of Balaban's Line intersection algorithm in Mathematica which works for 2d. However, I need to find whether a ray(line) ...
8
votes
1answer
1k views

How do I get Mathematica to show a number in non-exponential form? [duplicate]

Sometimes I make a calculation in Mathematica that produces a big number, which Mathematica shows like so: -1.52522*10^7 This is annoying to me, because I want ...
0
votes
2answers
121 views

help with StringJoin [duplicate]

dollarWon := 100 "(" <> Style["$" <> ToString[dollarWon], If[dollarWon >= 0, Darker[Green], Red]] <> ")" I am getting an error: String ...
4
votes
3answers
448 views

How to find the minimum of this constrained expression?

Let $x$, $y$, $z$ be three nonegative real numbers and $x^2 + y^2 + z^2 = 5.$ Find the minimum of the expression $$E=\dfrac{1}{2}x^2 y^2 + y^2 z^2 + z^2 x^2 + \dfrac{96}{x + y + z + 1}.$$ I tried ...
2
votes
1answer
368 views

How do I manipulate a 3D point plot?

I currently have a recursion done in 3D. At the moment, I am able to manipulate the points, but I cannot use "Joined->True" to connect them Currently this is what I have ...
2
votes
0answers
60 views

How to retroactively merge cell change history according to a merge interval

I recently noted that there is an option in the options inspector to set a merge interval for cell changes. This (I think) prevents a quick series of changes from spamming your notebook history with a ...
2
votes
2answers
327 views

Help with 1-dimensional random walk [closed]

I would like to simulate the evolution of a bankroll of a 2 player game where you have the probability of winning p. If a player wins, the bankroll grows by 1 unit minus a fee that each player pays, ...
3
votes
2answers
105 views

Select gives different answers in versions 8 and 9

Consider the code below: s = Solve[(3 - Cos[4*x])*(Sin[x] - Cos[x]) == 2, x, InverseFunctions -> True]; Select[s[[All, 1, 2]], Element[#, Reals] &] In MMA ...
5
votes
4answers
478 views

Any rule of thumb for converting a simple mathematical expression into a pure function?

By simple mathematical expression I mean one with a few functions and few variables copied into MMA in a mechanical way from a math book. For example this one, giving the distance between two points ...
0
votes
1answer
51 views

float output left in CDF

I'm experimenting with embedding a CDF on a Wordpress site and while it mostly works, the plots are running out of room along the right edge. It seems like if the images were floated left they would ...
0
votes
1answer
411 views

Mathematica command for type checking?

I have a program where users can enter mathematica commands that can evaluate to any of the standard numeric types (complex, real, int, etc.), or to boolean values. Moreover the users can enter ...
4
votes
1answer
7k views

How to graph a sphere with cartesian equations?

I'm new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations. For example in sphere's case $x^2+y^2+z^2=1$ I tried to use ...
17
votes
3answers
713 views

Select performance

I am fairly new to mathematica and working my way thru Paul Wellins book on Mathematica programming so experimenting with various language constructs. I was experimenting with ...
1
vote
1answer
423 views

how to show value of y-axis value using manipulate to select x-axis value

How to add a slider for the x-axis that shows the value of the y-axis based on the position of the slider. Basically providing the result of the probably given a specific lot percent defective, lpd ...
13
votes
2answers
1k views

Basins of Attraction

How does one shade the basin(s) of attraction of a phase plot in Mathematica? I have been trying to do this using the system $$\begin{align*} \dot x &= y\\ \dot y &= -9\sin(x) - 0.20y ...
2
votes
1answer
151 views

How can I place gui controls inside Grid? [duplicate]

In all my apps, I am facing a problem about placing the Gui controls inside Grid. For this purpose, I wrote three functions. The first function, ...
4
votes
1answer
708 views

Legend for ListContourPlot

Consider this example below for ListContourPlot. ListContourPlot[ Table[Sin[j^2 + i], {i, 0, Pi, 0.02}, {j, 0, Pi, 0.02}], PlotLegends -> Automatic] I ...
40
votes
5answers
4k views

How can this image (optical illusion) be created with Mathematica?

I came across this image the other day: and liked the sensation of it pulsing. I was wondering if anyone would know how to create something similar with Mathematica (without the Pink Floyd Dark ...

15 30 50 per page