# All Questions

2k views

### Saving Mathematica kernel state?

If I save a notebook, I only save what I see. That is, if I close Mathematica and reopen the notebook later, all previous calculations are lost, except for those things I've output. Now I know that ...
518 views

### How can I make threading more flexible?

Threading automatically with Listable functions requires the argument expressions to have the same length (or for one of them to be atomic). For nested lists the ...
3k views

### Generating a broken or snipped axis in ListPlot

I have two data sets, data1 and data2. For example: ...
1k views

### Customizing syntax highlighting for private cell styles

Is there any way to set up a cell style with a particular syntax highlighting? For example, I'd like to have a CProgram cell to write in blue the C special words. I have done it by setting ...
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### Does Mathematica support variable frame rate for any video format, in analogue of GIF-style “DisplayDurations”?

The good old GIF animation format allows us to set the duration of each individual frame in the animation separately. This is especially useful if some frames in ...
3k views

### Replacing composite variables by a single variable

To replace a single variable by another variable, one can simply use the the replace all (/.) operator (e.g., ...
1k views

### Usage of Assuming for Integration

For some reason, when I enter the following integration in Mathematica Assuming[{k ∈ Integers}, Integrate[ Exp[ I k t], {t, -π, π}]] the result turns out to be ...
2k views

### Using D to find a symbolic derivative

I need to do the following: Define a function Take the derivative of this function and have a look at the symoblic representation Substitute in some values With the bonus that I want to use the ...
15k views

### Labeling individual curves in Mathematica

I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I've read and my personal ...
2k views

### Once more on object orientation in Mathematica: does it have to be so hard?

Recently I came across a set of problems which would be solved most easily within an object-oriented approach. I first attempted to solve them by other means, but found the complexity of the code ...
4k views

### Calling MATLAB from Mathematica

How can I call MATLAB functions directly from Mathematica and transfer data/variables between the two systems?
2k views

### How can I implement dynamic programming for a function with more than one argument?

Dynamic programming is a technique for avoiding the repeated computation of the same values in a recursive program. Each value computed is immediately stored. If the value is needed again, it is ...
3k views

### Extract current viewing parameters from a 3D view?

Is there a way to find out the current viewing parameters of a 3D view? What often happens is that I create a view, for example: ...
588 views

### What's inside InterpolatingFunction[{{1., 4.}}, <>]?

I'm curious what's inside the InterpolationFunction object? For example: ...
2k views

### Antialiasing in 3D

Is it possible? Is it platform specific? Does it rely on the graphics hardware? Why does the antialiasing slider under Preferences > Appearance > Graphics do nothing? I remember seeing some ...
783 views

### Prepend Information to Warning Messages

I have a function running within a Do loop that sometimes issues a warning. I'd like to prepend the warning with the loop ctr so that I can go back and debug that instance later. Basically, I would ...
5k views

### What is the most efficient way to add rows and columns to a matrix?

Say I have a matrix m and a vector v. ...
752 views

### Common subexpression from two expressions

I am working with some unpleasantly tedious polynomials, which need to be manipulated in various ways (integrate with respect to some variable, differentiate with respect to another). Since these ...
1k views

### How do I perform string matching and replacements?

What are, and how do I use Mathematica's string matching and replacement tools?
1k views

### Problem with ContourPlot

I tried these ...
6k views

### Recovering data points from an image

Unfortunately, some data can only be obtained in picture form (Japanese publications anyone?). Since this cannot be worked with, it has to be converted to a dataset that can; I was wondering whether ...
2k views

### Profiling from Mathematica

I've always wished I could do some profiling like you get in Wolfram Workbench, but directly from Mathematica, without using or having Workbench. If it is possible, how can I do it?
8k views

### How can this confetti code be improved to include shadows and gravity?

Here's some confetti: ...
2k views

### Automatically generating a dependency graph of an arbitrary Mathematica function?

Has anyone written a function to pull the function dependencies of a function? That is, it would be nice to have a function that returns a list of function dependencies as a set of rules, terminating ...
7k views

### How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?

I am seeking a convenient and effective way to calculate such geometric quantities. I've used packages like TensoriaCalc, but they don't work at all time. ...
2k views

### Generating evenly spaced points on a curve

In the KnotData package a simple command such as points = Table[KnotData[{3, 1}, "SpaceCurve"][t], {t, 0, 2 Pi, 0.1}]; will ...
2k views

### I'd like to display field lines for a point charge in 3 dimensions

I'd like to display field lines for a point charge in 3 dimensions. Not a force field (short arrows) but continuous field lines that start on the charge.
510 views

### What can I use as the second argument to Return in my own functions?

Having found out about the second argument to Return I played a bit with it, and the following tests all resulted in ...
2k views

### how to differentiate formally?

I have been wrapping my head around this for a while now and I have not found a solution so far. I want to work with an arbitrary number of variables in mathematica and use some built in functions. ...
4k views

### Is it possible to change the color of plot in Show?

For example: p = Plot[Sin[x], {x, 0, 1}] Is it possible to write options in Show to change the curve's color for example into ...
1k views

### How to load a package without naming conflicts?

This question applies to any package, but I encountered this problem while working with graphs. There are symbols in the Combinatorica package (such as ...
632 views

### How to inject an evaluated expression into a held expression? [duplicate]

I know that there are methods to structurally manipulate held expressions (discussed e.g. here), but I failed to apply those for this particular problem: ...
2k views

### How to pass a symbol name to a function with any of the Hold attributes?

Given a function with the attribute HoldFirst, HoldAll or similar, and a variable, list, how ...
444 views

### Using Evaluate and Evaluated -> True in Plot

A few use cases: (1) This, as expected, returns (almost) immediately: f[x_?NumericQ] := Evaluate[(Pause[1]; x)] Plot[f[x], {x, 0, 1}] (2) This takes ...
12k views

### $\LaTeX$ and Mathematica

I quite often would like to draw graphics in my $\LaTeX$ documents using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems I would ...
4k views

### Metaprogramming in Mathematica

Being functional, and having no "quotation", i.e. essentially treating data and programs semantically same, Mathematica seems naturally capable of doing metaprogramming. But could anyone construct a ...
5k views

### How to make a 3D globe?

There are many ways to create a 3D Earth that is rotatable (see here, here, related here), but most of them have some drawbacks. These issues mainly stem from either ...
5k views

### How can I extract data points from a black and white image?

Consider the following graph (source): Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they ...
2k views

### Implementing a first person view of 3D objects in a scene

I've created the following scene with a Chinese-style building surrounded by trees, and a horse and a rabbit grazing on the grass in Mathematica (don't ask me why there's a bust of Beethoven in ...
3k views

### How can I make an X-Y scatter plot with histograms next to the X-Y axes?

I just saw a nice plot there: How could I implement that in Mathematica — by which I mean the plot structure, not so much the styling.
2k views

### How to distribute proprietary Mathematica code

If I want to make package-code completely unreadable, in a way that the end-user can only call my functions, but has no way to re-engineer my definitions, how would I do that? I know I can use ...
2k views

### Point Renderings Slightly Off in Mathematica

The Mathematica code ...
1k views

### Map a function across a list conditionally

It seems that this is a really basic question, and I feel that the answer should be obvious to me. However, I am not seeing. Can you please help me? Thanks. Suppose I have a list of data ...
647 views

### How to make MapAt work with Span?

Span (;;) is very useful, but doesn't work with a lot of functions. Given the following input ...
1k views

### Partition a set into subsets of size $k$

Given a set $\{a_1,a_2,\dots,a_{lk}\}$ and a positive integer $l$, how can I find all the partitions which includes subsets of size $l$ in Mathematica? For instance, given ...
773 views

### Resource management in Mathematica

I am using a library that has functions like createSomeObject[] and deleteSomeObject[obj]. It is an interface to a C language ...
3k views

### Efficient way to generate random points with a predefined lower bound on their pairwise Euclidean distance

Using Mathematica what is an efficient way to generate a list of $n$ random two dimensional points $\{x_i,y_i\}$ where $i=1,...,n$ so that no two points $p_1$ and $p_2$ in the list has an Euclidean ...
2k views

### Open Excel file with Mathematica

I would like to open an Excel file and manipulate it as a COM object. While I'm able to open an instance of excel with ...