# All Questions

757 views

### ArcTan[0,0] numeric approximation

I've noticed that the numeric approximation of ArcTan is a bit different from the symbolic one. If I write ArcTan[0,0] I ...
794 views

### How do I find all the solutions of three simultaneous equations within a given box?

Sometimes, one needs to find all the solutions of three simultaneous nonlinear equations in three unknowns \begin{align*}f(x,y,z)&=0\\g(x,y,z)&=0\\h(x,y,z)&=0\end{align*} within a ...
474 views

### Replicating a discontinuous graph

I'm trying to replicate a graph from my math book for my notes as well as to learn Mathematica. I was hoping someone would be able to help me figure out how to add the open points to the graph, and ...
1k views

### Delaunay Triangulation for 3D Surface Data

I want to do a Delaunay triangulation on scattered 3D surface data. Mathematica itself does it only for 2D through the command DelaunayTriangulation[], which gives ...
212 views

288 views

### Efficient dynamic drawing

So for example I have this code: ...
154k views

### xkcd-style graphs

I received an email to which I wanted to respond with a xkcd-style graph, but I couldn't manage it. Everything I drew looked perfect, and I don't have enough command over ...
1k views

### Make a density list plot/histogram from large, pre-binned data set?

I have a large data set consisting of $\mathcal{O}(10^9)$ two-dimensional points. In order to save memory and time I have pre-binned these into a uniform grid of $500 \times 500$ bins using Fortran. ...
269 views

### How do I dynamically change Manipulate controls?

What I'd like to be able to do is dynamically change the axis of a 3D plot inside a manipulate. For example if I have a function that has three input variables I'd like a 3D plot using 2 of the ...
715 views

### Can Mathematica Handle Open Intervals? Interval complements?

Open Intervals Following up on this question, I was wondering whether Mma can handle open intervals. For example, the union of the intervals, $$1<x<5$$ and $$5<x<8$$ should not ...
844 views

### Union and Intersection of intervals

I have two sets $A = \{1 \leq x \leq 5\}$ and $B = \{5 \leq x \leq 8\}$. Now I want to find the Union and Intersection of $A$ ...
732 views

### Enlarge an image and increase its resolution

An ongoing purely recreational project. I got my introduction to image processing with this Rotating perspective... question and had a lot of fun with it. Now I want to take it to the next step. ...
205 views

### Is it possible to specify a context-sensitive, “depth-agnostic” rewrite rule?

I'm using the term "depth-agnostic" in this post to describe structural patterns featuring a "target" sub-pattern that can occur "at any depth" relative to one or more "context" sub-patterns. As a ...
788 views

### In a ListPlot of LinearModelFit, Fill to the regression line

In the help for LinearModelFit, the regression line can be added to the scatter plot like this: Show[ListPlot[data], Plot[lm[x], {x, 0, 5}]] Is it possible to ...
558 views

### How to use mathematica to create school time-table?

I wonder if it is possible to use Mathematica for helping myself to create school timetable. I have a feeling that it requires quite simple optimization algorithm, but I have never been into ...
207 views

### How to get the results of Tally split into two separate lists

This is a kind of a followup to my previous question. I am starting with a long list of plane coordinates, like this one: ...
828 views

### How to specify DataRange in a ListPlot with an imported set of data

So I've been trying to import a large set of data (6900 point pairs) from an excel (.xls) file. The Exel file has 2 columns of numeric data. I've also been trying to plot this data, but when I do, it ...
457 views

### How to display equations without Mathematica simplifying them?

Say I'm trying to make a simple multiplication table and used Table[i"x"j"="i*j,{i,1,9},{j,1,9}] I'm trying to make it so that I can get a table of equations, ...
181 views

### How to make “molbio-style heat maps” in Mathematica [duplicate]

Possible Duplicate: How to combine ArrayPlot's? [NB: This question is specifically addressed to those who have used (or attempted to use) Mathematica to generate "heat maps" (as the ...
189 views

### Tracking FindRoot errors in NestWhileList and Table

I'm solving many systems of two equations by varying the initial parameters. I'm running FindRoot in a NestWhileList where the ...
269 views

### From iterative to functional

How to write this small piece in a functional way (ie. without state variables)?: ...
591 views

### Map-Thread-Through-Apply a list of functions onto a list of (lists of) values

I have a list of functions: fns = {f, g, h} and a list of triples: ...
287 views

### How to speed up drawing a tangent plane?

I have this code to produce an interactive visualization of a tangent plane to a function: ...
462 views

### Does Mathematica use the Elliptic Curve Method (ECM) in FactorInteger[]?

I'm not a mathematician, and I'm not even going to pretend that I understand anything of the ECM. But I know it can be a fast method for factorization. I benchmarked the factorization of ...
198 views

### Map Input A B C to MyProduct[A,B,C] (NOT to Times[A,B,C])

In writing my own (noncommutative) product I want to avoid typing redundant symbols like A.B.C or A**B**C, I just want to type ...
182 views

### tricky memoization

Let's say I have the NDSolve example for documentation involving splitting 2nd order into set of 1st order ODEs: ...
264 views

### Are there any offline tutorials for Mathematica?

As can be seen from my questions, I am struggling to make Mathematica do something useful. The amount of tutorials on the Wolfram web site is a bit overwhelming, especially that I don't have too much ...
2k views

### How to find (numerical) value of a derivative at point?

I have the following function: f[0, 0] = 0 f[x_, y_] := Exp[-(x^2 + y^2)^(-1)] How do I find its partial derivatives at any given point, including $(0,0)$? This ...
241 views

### How to connect a checkbox with part of the graphics?

I'd like to have a checkbox in a Manipulate expression, governing whether part of the graphics is displayed or not. For instance, assume that I have a surface with ...
340 views

### PDF exports of ArrayPlot's are fuzzy (OS X)

[The following problem occurs on OS X; I don't know if it also occurs with other OS's.] If I produce a Graphics object with ...
326 views

### how to read in a file in the same directory?

Now I am writing a small package. I have written several files and put them in the same directory. And some files need to read in or include another file in the same directory. But when I simply write ...
225 views

### Importing and manipulating strings - time data

I have a list of time durations, which are strings of the form: "hh:mm:ss". Here's a sample for you to play with: ...
203 views

### How to repeat a plot with different options

I'd like to have first a function plot and then the same plot repeated inside a Manipulate, with additional things (like tangent planes etc.). I can do ...
254 views

### How to compile Map and MapAt

I have a long list (say, million of elements, like this one: {{{1.0, 2.0}, 3}, {{4.0, 5.0}, 6},...} I would like to compile a function ...
957 views

### Are there suitable versioning systems for Mathematica notebooks?

I am considering a project using Mathematica and openCL. I know that the openCL C source code can be tracked. Has anyone used a versioning site or software so multiple developers can modify a common ...
150 views

### Transform sequential cell operations to programmatic workflow

Let's say I have a workflow that involves importing images and turning them into an animated gif. Here's how I currently have it setup: Import Images: ...
263 views

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### How to combine ArrayPlots?

Define: fat = ArrayPlot[RandomReal[1, {20, 10}], ColorFunction->"Rainbow"]; skinny = ArrayPlot[RandomReal[1, {20, 1}], ColorFunction->"Rainbow"]; What ...