1
vote
1answer
474 views

How to solve this integral

I'm trying to deal with this article, but I don't understand how equations 5.9 and 5.10 were obtained. I tried to use Mathematica 8 to solve it, but the answer was different. I have a problem with ...
17
votes
2answers
698 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 ...
10
votes
1answer
724 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 ...
12
votes
2answers
426 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 ...
5
votes
1answer
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 ...
2
votes
0answers
192 views

Best Practice for using Notation, $Pre, MakeExpression in a package

I'm setting up a package that defines a custom Notation. I'd like to inquire about best practices and possible issues of: using the Notation Package using $Pre ...
6
votes
1answer
271 views

Efficient dynamic drawing

So for example I have this code: ...
411
votes
6answers
151k 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 ...
11
votes
1answer
988 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. ...
4
votes
1answer
237 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 ...
14
votes
3answers
653 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 ...
2
votes
1answer
806 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 $A$ ...
10
votes
1answer
654 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. ...
7
votes
1answer
195 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 ...
19
votes
5answers
697 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 ...
3
votes
1answer
508 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 ...
2
votes
1answer
199 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: ...
0
votes
1answer
593 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 ...
8
votes
5answers
411 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, ...
0
votes
0answers
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 ...
3
votes
1answer
180 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 ...
11
votes
2answers
247 views

From iterative to functional

How to write this small piece in a functional way (ie. without state variables)?: ...
17
votes
5answers
551 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: ...
3
votes
2answers
255 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: ...
7
votes
0answers
415 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 ...
5
votes
3answers
197 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 ...
2
votes
1answer
170 views

tricky memoization

Let's say I have the NDSolve example for documentation involving splitting 2nd order into set of 1st order ODEs: ...
7
votes
1answer
241 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 ...
4
votes
2answers
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 ...
6
votes
2answers
208 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 ...
4
votes
2answers
313 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 ...
7
votes
3answers
282 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 ...
6
votes
3answers
202 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: ...
0
votes
1answer
189 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 ...
6
votes
1answer
242 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 ...
21
votes
4answers
845 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 ...
4
votes
1answer
145 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: ...
7
votes
4answers
651 views

How to combine ArrayPlots?

Define: fat = ArrayPlot[RandomReal[1, {20, 10}], ColorFunction->"Rainbow"]; skinny = ArrayPlot[RandomReal[1, {20, 1}], ColorFunction->"Rainbow"]; What ...
7
votes
1answer
91 views

$CurrentLink passing down in MathLink SetDelayed functions

I would like to utilize the MathLink option of having each Install of my package result in a linking object which I can use to control when and how certain elements ...
8
votes
3answers
196 views

Identify which cell uses most memory in front-end

Even though the mathematica front-end is much more robust than it used to be, everyone must have noticed that when a few 3D graphics are involved, the front-end produces very large notebooks which ...
4
votes
0answers
126 views

Creating a PolyhedronData[] structure for custom polyhedra [duplicate]

The PolyhedronData[] structure is wonderfully rich. I would like to create data for my own polyhedra, not any of the many that Mathematica provides. Is this ...
3
votes
1answer
363 views

Efficient way to perform elementary integration step with NDSolve internal method

I'm trying to tweak the NDSolve function to perform one elementary integration step (using some explicitly selected stepping algorithm via ...
11
votes
2answers
789 views

How do I compute sidereal time and JD?

There was once a package that provided a wide range of functions for computing astronomical information. This package now appears to be out of date; but as near as I can tell, many of the useful ...
1
vote
1answer
1k views

Plot cubic root which includes the negative graph [duplicate]

Possible Duplicate: Finding real roots of negative numbers (for example, $\sqrt\[3\]{-8}$) Yes, I know there are other Threads which have similar questions and yes I read them but I am just ...
3
votes
1answer
370 views

Control over depth-first scan and breadth-first scan

Is there a way to conditionally take control/modify the flow during a depth-first scan or the breadth-first scan ? Say, for example, if a particular node if found, consider it as a leaf-node and ...
1
vote
2answers
166 views

Scalar product of two vectors have the least value

In geometry 3D, let $A(1,2,-3) $ and $B(-1,4,1)$ are two points. In the plane $(P):2x-3y+3z-17=0$, find a point $M$ such that the scalar product of two vectors $AM$ and $BM$ will have the least value. ...
5
votes
1answer
177 views

How to convert String to an Expression inside Manipulate which depends on control variable

Normally, in Global context, these 2 are equivalent eqn = "r-x"; r = -2; Plot[ToExpression[eqn], {x, -5, 5}] and ...
8
votes
1answer
212 views

Elementwise, compilable min function

I am trying to implement efficiently a transfer-matrix like algorithm. On each iteration, I have two vectors $x=\{x_1,\dots,x_n\}$, $y=\{y_1,\dots,y_n\}$ with real numbers and I need to compute the ...

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