# All Questions

59,249 questions
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: ...
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 ...
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 ...
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: ...
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 ...
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### 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 ...
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 ...
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, \$...
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### LocatorPane and PlotRange

Consider the following snippet from the documentation on LocatorPane ...
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### 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. ...
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 ...
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 ...
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 ...
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, ...
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 ...
6k views

### Relative paths for portable notebooks in Mathematica

I cannot find how to use relative paths in Mathematica. My directory structure is simple. ...
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: ...
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 ...
327 views

### LocatorPane, selecting multiple Locators

Consider the following snippet ...
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 ...
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 ...
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 ...
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 ...
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: <...
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 ...
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 ...
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-...
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.
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 ...
11k views

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?