7
votes
2answers
202 views

What do AstronomicalData's “SetTime” and “RiseTime” values refer to?

What astronomical event do AstronomicalData's "NextRiseTime", "NextSetTime", ...
9
votes
1answer
225 views

How do I determine astronomical transit times?

Mathematica, through the "legacy" Scientific Astronomer package, used to have the ability to easily determine accurate transit times of astronomical objects simply, with ...
1
vote
1answer
64 views

Grid — Row expressions not evaluated [closed]

Can anyone explain why in the following Grid expression the Row expressions are not evaluated ... ...
1
vote
3answers
932 views

How to plot a 3D list of points [closed]

I have 3 variables {Eff[i][j], i/15, j/100}. I need to plot them as a 3D figure, the height of the figure is Eff[i][j], which is ...
3
votes
1answer
192 views

One Integral — Two Results

I compared Mathematica's default integral evaluation to what you get by computing the indefinite integral and then plugging in the limits. (I did this because the latter approach was much faster for ...
5
votes
2answers
266 views

Why is an integer not considered as a real?

Please consider the following: zeros={0.,0}; data={1, 0., 0}; DeleteCases[data, #]&/@zeros Head/@zeros (*{Real, Integer}*) (*{{1, 0}, {1, 0.}}*) For my ...
3
votes
2answers
741 views

Combining manipulated plots

Let's say I have two manipulated plots: Manipulate[Plot[Sin[a x], {x, 0, Pi}], {a, 0, 10}] Manipulate[Plot[Cos[b x], {x, 0, Pi}], {b, 0, 10}] How can I create a ...
7
votes
1answer
205 views

Is there a way to convert mathematica code to OpenMP or OpenACC?

I see that Mathematica has limited support for things like OpenCL and CUDA, but what about other standards like OpenMP or OpenACC?
14
votes
2answers
503 views

How can I speed up the classic GA for graph coloring?

I'm trying to compute the chromatic number of this graph (which is 28): g = Import@"http://www.info.univ-angers.fr/pub/porumbel/graphs/dsjc250.5.col"; My genetic ...
8
votes
1answer
225 views

What is the complete list of valid FrontEnd Packet types?

In response to my question How can I get the unchanged Box form of an arbitrary expression? John Fultz answered with a method using the hilariously named ...
4
votes
1answer
187 views

Automatically expanding sliders in Manipulate

Is there some way to have all sliders expanded by default in a Manipulator object, i.e. as if I had clicked all "+" signs?
5
votes
1answer
158 views

Reading Early Version Notebooks

I have some very old Mathematica notebooks file (.m) files from Version 2. When I try to open them using Mathematica 8.0 (on a Linux system) Mathematica instantly shuts down (no error message - just ...
5
votes
1answer
115 views

lists of conditions

I have got coordinates in two list of Latitude and Longitude and would like to check if those coordinates are in a certain grid Example lists are: ...
6
votes
3answers
232 views

Wrapping EventHandler by Table

I am making a grid on the screen. The grid is composed of different expressions. I want all of them to have a Gray background, which turns into a ...
0
votes
1answer
172 views

Problem setting up edge rendering function

I have a graph, and I want my EdgeRenderingFunction to colour the edges based on the vertex they originate from. In this toy example, I'm trying to get the edge ...
16
votes
4answers
970 views

How to speed up the function DelaunayTriangulation?

First define a function meshGrid to generate some points: ...
4
votes
3answers
612 views

Transform a Sum into a List

I want to turn a sum like this sum =a-b+c+d Into a List like this: sumToList[sum]={a,-b,c,d} How can I achieve this?
2
votes
2answers
822 views

Why doesn't Mathematica solve $x=\cos\,x$ properly? [duplicate]

Why doesn't Mathematica solve x == Cos[x] properly? Both Solve and NSolve fail with the ...
6
votes
3answers
271 views

Composition of mappings not working as expected

I have two functions $f,g:\mathbb{R}^2 \to \mathbb{R}^2$ and I define a third one $h:\mathbb{R}^2 \to \mathbb{R}^2$ as the composition $$h(x,y) = g(f(x,y))$$ I'm trying to get this function into ...
4
votes
2answers
373 views

How to solve an eigensystem faster?

I have a module that I need to call 1-10 million times in my program. Currently, it is taking several hours to run so I am hoping that I can cut down some runtime with your help. ...
4
votes
2answers
233 views

How can I use Max[] in a function that is passed a list not find the max of the list

For most functions in Mathematica, passing them a list will call the function on each element of the list. For example: ...
0
votes
1answer
198 views

How can I remove orange-box around the Graphics3D?

I don't know whether this is a correct question or not, but I played from two days on this problem and still I didn't find a solution. The save button is enabled whenever we have to specify ...
2
votes
1answer
132 views

Randomizing a lab

I teach a class where students do a weekly lab in Mathematica. They do it in a computer lab, and because there are many of them, and only one of me, I encourage them to help one another. ...
3
votes
0answers
126 views

Insert EndNote citation in Mac OS

I'm trying to insert citations in a notebook. I found a thread that goes back to 2010 saying that the Endnote plugin for Mathematica is not supported on Mac OS. Does anyone know whether this is still ...
3
votes
0answers
41 views

Annoyance: Plot Markers disappear when ListPlot options are set in SetOptions instead of in ListPlot [duplicate]

Possible Duplicate: Why does ListPlot ignore some global options? Using this data: ...
1
vote
2answers
79 views

Using non-Graphics primitives when exporting to .cdf

I'm trying to embed a "Manipulate" applet I've created into a webpage by embedding a .cdf. I'm running into a problem with displaying outputs from functions I've written. Here is a simpler example ...
5
votes
4answers
1k views

How to solve this logarithmic equation?

The equation $$x^2\cdot\log_2\dfrac{3+x}{10}-x^2\cdot\log_{\frac{1}{2}}(2 + 3x)=x^2 - 4+2\cdot\log_{\sqrt{2}}\dfrac{3x^2+11x+6}{10}$$ has two solutions for x, namely 1 and 2. I tried ...
6
votes
2answers
247 views

Grid - problem with ItemSize being ignored

I have run into another problem with Grid today. An explicitly specified ItemSize is being ignored: ...
9
votes
2answers
714 views

Overlapping accurately Images and Graphics (without loss of resolution)

Context In a previous post, I learned how to produce these kind of plots, which are of interest in astrophysics and geophysics. I am now interested in combining them. Attempt For this purpose, ...
4
votes
1answer
293 views

Exporting Cyrillics in PDF on Linux

I'm using Mathematica from Ubuntu. I need a normal font to display cyrillics inside PDFs. Any default font is very ugly, letters are too close together: ...
4
votes
2answers
279 views

Define product derivative

How do I define the $n$th product derivative of a function in Mathematica? The first product derivative $f^\ast$ of a function $f$ is $$ f^\ast(x)=\exp\left(\frac{f^\prime(x)}{f(x)}\right) $$ The ...
6
votes
2answers
745 views

Singularities using VectorPlot

I am trying to plot a vector function of a fluid flow given by $\vec{V} = (\frac{-\cos(\theta)}{r^2},-\frac{\sin(\theta)}{r^2})$ I am trying to plot it in Mathematica using the command below, I ...
7
votes
2answers
657 views

Memory running out generating ContourPlot3D

The code below ...
6
votes
3answers
336 views

Parametric regions

I'm trying to plot $a x^2 + b x + c$ where $a, b, c$ (and $x$) take on a range of values. I tried ...
13
votes
3answers
651 views

Approximating an ornamental curve

How do I go about approximating this ornamental curve? Note that the curve has somewhat variable thickness as typical in calligraphy, which I would also like to replicate. The excellent reference ...
11
votes
1answer
1k views

Vertically aligning two separate plots

How do I vertically align plots so that the two plots are displayed in a way that lines up with respect to the axes? The code I have so far is: ...
4
votes
2answers
206 views

Vectors in a spherical shell

I have written code that randomly generates a 3D vector of random magnitude. I now want to create a histogram of how many vectors lie in the concentric spherical shells (n*delta r, (n+1)delta r) ...
4
votes
1answer
59 views

WordBoundary issue in StringReplace

Why does the following StringReplace pattern match: ...
27
votes
2answers
1k views

Mollweide maps in Mathematica

Context In my field of research, many people use the following package: healpix (for Hierarchical Equal Area isoLatitude Pixelization) which has been ported to a few different languages (F90, C,C++, ...
2
votes
1answer
253 views

Do “objects” in Mathematica have to be declared?

A while ago I learned a trick which allows one to imitate object-oriented programming in MMA using SubValues: ...
0
votes
3answers
1k views

How do I place frame ticks without having corresponding numbers? [duplicate]

Possible Duplicate: Remove tick labels, but retain tick marks in RegionPlot (and related functions) I need to display a 2D graph, say $y=x^2$ with tick-marks along the $x$ and $y$-axes but ...
3
votes
2answers
496 views

Subspaces in Mathematica

I'm working on a research project and I need to learn how to use Mathematica to calculate subspaces. Specifically I plan to solve the following operations and I would greatly appreciate if you could ...
4
votes
3answers
468 views

Grid - sizing and spacing problems with spanning cells

I am trying to set up a Grid with cells that span two rows and are centered on those rows, but I am having troubles with the sizing and, therefore, spacing of the ...
11
votes
4answers
379 views

Grid - Item - Alignment to decimal problem

I've run into a Grid layout problem for which I don't know a solution. I want to specify alignment to a specific character such as a decimal and an ...
0
votes
3answers
824 views

How to make all values positive?

So I have a list of data that contain both positive and negative values, and I am wondering what I have to do in order to make all the numbers positive.
1
vote
1answer
106 views

How to find the values of $m$ so $A \cap B = \emptyset$ and $A \cup B = (-3,+\infty)$?

I have two intervals $A = (-3, m^2- 2]$ and $B=[m, +\infty)$. How to find the values of $m$ so that $A \cap B = \emptyset$ and $A \cup B = (-3,+\infty)$? I tried ...
3
votes
1answer
94 views

CycleIndex in v8

If I type ?CycleIndex I get Information::notfound: Symbol CycleIndex not found. >> If I then type ...
7
votes
2answers
322 views

Can I put tooltips in a Graph?

This doesn't work: Is there a way to do this? My real goal is to identify the second links in the graph below, which shows the results of a webcrawl (using this code). I'm open to another ...
4
votes
3answers
718 views

How to prove an expression by method of mathematical induction?

I want to prove the expression $$1^2 + 2^2 + 3^2 + \cdots + n^2 = \dfrac{n(n+1)(2n+1)}{6}$$ by method of mathematical induction with Mathematica, but I do not know how to start. How do I tell ...
3
votes
1answer
351 views

Solving the Sine Gordon PDE in mathematica

how can i solve this equation in mathematica? this is sine-gordon eq. but the boundary condition can not recognized by mathematica . thank you for you attention. ...

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