All Questions

3
votes
2answers
1k views

Animating a 3-D arrow given the vector's x, y, and z components as a function of time

I am trying to show how a vector M varies over time. I have the following code: ...
10
votes
2answers
1k views

Creating and editing new stylesheets

I'm trying to create a stylesheet, but the process has become painful. I'm sure that this has to do something with resetting something in Mathematica everytime I make changes to the stylesheet. To ...
0
votes
1answer
1k views

On the parallelization of matrix multiplications in Mathematica 8

I have installed Mathematica 8, but I think the commands for parallelizations do not work! Even when I try to test the example in the Help of Mathematica, I face with ParallelDo::nopar: No ...
18
votes
6answers
16k views

How to get rid of warnings when using Solve on an equation with inexact coefficients?

When I solve this equation in Mathematica 8, I can get the right answer, but with some uncomfortable warnings. Equation: ...
9
votes
3answers
2k views

Improve speed for calculating a recursive sequence

I want to calculate following recursive sequence: $\alpha_{0}=0,\\ \cos(\alpha_{i})=\cos(\alpha_{i-1})\cdot\cos(\beta_{i})+\sin(\alpha_{i-1})\cdot\sin(\beta_{i})\cdot\cos(\gamma_{i}).$ In ...
21
votes
3answers
14k views

Is there a way to make the tick marks larger?

In a Plot (actually, a Graphics) command, I'd like to make the actual tick marks larger than they are, but I can't find an ...
13
votes
1answer
948 views

Exporting numbered equations to HTML/TeX using conversion rules

This question is a follow up from this one. It may also be considered a duplicate since I have already asked this question in stackoverflow almost a year ago. For a background on using numbered ...
38
votes
2answers
1k views

Is it possible to make Mathematica reformulate an expression in a more numerically stable way?

I'm writing a numerical optimization, and I'm having a problem with an expression of the form $$ e^{-t} (1+\mathrm{erf}(t)) $$ The overall shape of the function looks correct, but when $t$ is small, $...
20
votes
3answers
1k views

LocatorPane and PlotRange

Consider the following snippet from the documentation on LocatorPane ...
4
votes
1answer
2k views

Incorrect solution of diffusion equation with Neumann boundary conditions

I want to set up a PDE model, which takes a two-dimensional diffusion equation into account. The key problem is that I have some trouble in solving the two-dimensional diffusion equation numerically. ...
5
votes
1answer
391 views

Where do I get the mdefs.h file?

I want to generate some C code, and the reference here says that Mathematica comes with a mdefs.h file, but I cannot find it. Is there a place where I can download ...
15
votes
2answers
992 views

Exporting notebook to HTML, using conversion rules

The idea is to export the whole notebook to HTML with all the math equations in latex form. In this way we can add the mathjax script and it will take care of the math. Suppose we have the following ...
2
votes
1answer
246 views

What is an alternative to using backticks in separating namespaces from function names?

What is an alternative to the backtick (`) in separating the namespace from the function name? Can the function be called without using this symbol? I think in ...
9
votes
2answers
1k views

Rapidly binning 3D data

I have a set of data (about 20 million datapoints for my real data) of the form {x, y, z, m}. There are 3 spatial coordinates x, ...
10
votes
1answer
697 views

Making cells group

After reading rcollyer's post I'm still not able to understand how grouping rules work. Here is a problem I'm facing. What I want is to create a new title, section and subsection styles. I want the ...
26
votes
4answers
6k views

Relative paths for portable notebooks in Mathematica

I cannot find how to use relative paths in Mathematica. My directory structure is simple. ...
5
votes
1answer
350 views

Noticeable slowdown in graphical performance when using manipulate

I have been making these mathematica 3D objects that involve a molecule with some sort of surface displayed above them. This is done fairly easily by: ...
13
votes
2answers
1k views

Restrict Locator to a certain graphic inside Manipulate

I would like to restrict the Locator inside Manipulate to a certain graphic. For example if I display two graphs, I would like to be able to click on the right one and use this information in other ...
8
votes
1answer
327 views

LocatorPane, selecting multiple Locators

Consider the following snippet ...
4
votes
2answers
3k views

Computing the minimum number of terms required in a Fourier series to achieve a particular upper bound on the error

In a Fourier series, the maximum error bound is the difference of the function and the partial sum of its Fourier series. Within an interval, as we increase the number of terms of partial sums, the ...
2
votes
1answer
1k views

Reduce/Solve an equation with symbols in powers

I am trying to solve the following equation with respect to x. eqn = x^z + y == a; But when I do ...
11
votes
3answers
424 views

Using Gather to rearrange my data

I have a list of elements: {{1, 2}, {1, 5}, {2, 6}, {3, 7}, {4, 8}, {5, 6}, {5, 9}, {9, 13}, {10,11}, {11, 12}, {11, 15}, {15, 16}} I have to divide it into ...
21
votes
2answers
6k views

How to define a global variable when giving each notebook its own Context?

I have restricted the context of my notebooks to each individual notebook. So variables in each notebook are local and are not seen in another notebook. But in two of my notebooks I have two ...
8
votes
2answers
216 views

“A number in base b” and pure functions: why doesn't b^^# & work?

Why do the following not work (in Mathematica 7)? 2^^ # & /@ {1000, 1101} and 2^^ # & @ 1101 This does work: <...
15
votes
1answer
556 views

Why does LogLinearPlot sample its argument outside the specified domain?

Bug introduced in 6.0 and fixed in 9.0.0 I experience a weird bug in the function LogLinearPlot. If the input is an interpolation function, such as the one created ...
16
votes
1answer
737 views

Estimating progress on plots

When plotting a slow function, it would be nice to know how much of the work has already be done. However due to the refinement algorithm, simply monitoring the integration variable doesn't give an ...
48
votes
3answers
9k views

How to create a progress bar?

I would like to create a progress bar tool that allows me to see how my computations are going. I found answers to this question on many sites, I even found a package for it ( http://www.physics.ohio-...
8
votes
2answers
2k views

Time-frequency analysis beyond wavelets

What possibilities are there for time-frequency analysis in Mathematica beyond wavelet decomposition? I could not even find a simple STFT.
5
votes
4answers
849 views

Add/replace a rule in a list of rules based upon the rule's lhs without regard for the rule's rhs

I have the following lists of rules: {x -> 1, y -> 2} {x -> 1, y -> 2, z -> 4} {x -> 1, y -> 2, z -> 2} For each list of rules, I would ...
62
votes
4answers
11k views

Plotting implicitly-defined space curves

It is known that space curves can either be defined parametrically, $$\begin{align*}x&=f(t)\\y&=g(t)\\z&=h(t)\end{align*}$$ or as the intersection of two surfaces, $$\begin{align*}F(x,y,...
58
votes
7answers
14k views

Saving data inside a notebook so that I don't have to run it again?

Piggybacking on this, I am somehow not fully convinced that I can't save data generated by a calculation in a mathematica file so that when I re-launch said file, I wouldn't have to run my ...
17
votes
1answer
2k views

How to install and configure Intel C++ Compiler for Mathematica correctly?

I wish to try the trial version of the latest Intel C++ Compiler for Windows with Mathematica. I have downloaded the current version of Intel® C++ Composer XE 2011 for Windows and installed only the "...
3
votes
2answers
523 views

How to find solutions that yield of root of unity?

I have a polynomial with coefficients that are integer polynomials in another (complex) variable. For example: 1 + (1 - v^2) #1 + (-3 - v^2) #1^2 + #1^3 & I ...
3
votes
1answer
323 views

LocatorPane, Dynamic and deleting locators

Compare the following two code snippets : Version 1 ...
6
votes
2answers
220 views

Control which variables get embedded inside Manipulate

While trying to analyse several different datasets I got what I thought was a good idea: define a "function" that returns a Manipulate object. But this has some ...
10
votes
1answer
448 views

Speed up DensityHistogram rendering (display)

When I tried to present some pre-calculated density histograms inside Manipulate I noticed that the display of DensityHistogram is extremely slow. Here is a simple ...
-4
votes
2answers
405 views

Indefinite Integral long time plotting

I have this equation: ...
10
votes
2answers
983 views

Shaping/simplifying equations in a certain way

A problem I am occasionally facing is to simplify an equation not to it's shortest form but to a form that is simple by other means. Often, this is grouping the term according to certain functions, ...
33
votes
3answers
1k views

Is using undocumented functionality a Bad Idea™?

Mathematica has a lot of very useful undocumented features. For example a hash table, a built-in list of compilable functions, additional options to CurrentValue, ...
5
votes
2answers
180 views

MemberQ weird inside Compile

Compile[{{x, _Real, 1}}, MemberQ[x, 2]][{2}] outputs False. In fact, it seems to get compiled as ...
40
votes
2answers
4k views

Is it possible to change the colors of the highlighted code in the Mathematica frontend?

With Format -> Edit Stylesheet... it is possible to adjust text-properties, text-colors, formatting of equations, etc of a notebook and to use this style-definitions again by installing it as ...
9
votes
3answers
2k views

Ηow to create an interpolated CDF from its samples?

I want to use a distribution I have only aggregate statistics on, namely its CDF sampled at certain points. I would like to keep it "nonparametric" (remain noncommittal on the parametric form), but I ...
5
votes
1answer
893 views

Finding ranges of a parameter for which a function is always positive

I have a complex function of a single variable expressed in analytical form, which also depends on a parameter. I would like to have Mathematica show me for which values of the parameter the real part ...
23
votes
1answer
3k views

How to control the page size when exporting as a PDF?

When I used Mathematica under Windows, I could control the page size of the pdf files created by Export[...,"PDF"] by setting the paper size in the print menu to ...
4
votes
2answers
1k views

Solving a linear equation in Mathematica

This should be easy but I can't seem to find the right way to do it. I have an equation of the form $a x + b x + c y + a z + d z = 0$, and I'd like to solve for relations between the parameters $a,b,...
20
votes
1answer
3k views

Finding the area, algebraic curve and jaggedness of an arbitrary shape

I start with a photograph of a shape (physically made by the flow of a liquid into another), of which I can extract the border, manually or using Mathematica's feature detect feature : Using the ...
6
votes
2answers
4k views

Select Solution with real (positive, etc) coefficients - ignoring variables

I often need to solve equations for numerical coefficients while preserving numerous variables (e.g. to preserve scaling relations). Thus I end up with a set of solutions like $$ \left\{-\frac{(0....
20
votes
3answers
25k views

Plot data from txt file?

I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4?
1
vote
4answers
182 views

Applying a for loop on Out[]

I have a number of expressions, each one is an output: Out[135], Out[136], etc. I wish to print all of these outputs in a C++ form using the function: CForm. I can apply it on each Out[] separately ...
19
votes
1answer
2k views

Rotating perspective of an image in the z axis

A purely recreational question, but one I hoped the community would find interesting enough to suggest a way to approach it. Let me preface this question with the admission that I have done nothing ...

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