# All Questions

102 views

### Algorithm in RandomChoice[{w1,w2,…}->{e1,e2,…},n]?

I wonder if someone happens to know the actual algorithm implemented in the particular overload of RandomChoice that handles explicitly presented discrete ...
147 views

### Using FunctionExpand to evaluate symbolic derivatives

Some symbolic derivatives of certain special function are not expanded automatically, but FunctionExpand often helps to get a derivative-free closed form ...
164 views

### Random filling of L-length line with l-length segments

I have discrete L-length line filled randomly with 2-length segments so its cover line with gaps 0 or 1. So we can describe cover configuration as sequence of gaps such as {0,0,1,0,1}. How I can ...
295 views

### Flow in pipeline graph

I have pipeline directed graph which has one source and several sinks ...
389 views

### Hatched bars and bar-specific background in BarChart

I would like to diagonally hatch the bars in BarChart and to have three different background colors for the different bars, like this: Any ideas how to ...
2k views

### Need 4D plot (3D + color for function) [duplicate]

I have a function f(x,y,z) of three variables and some constants: ...
471 views

### Integral of the Sinc product

Let as consider the following integral $$B_n = \int_0^\infty \prod_{k=1,3,5,\dots}^n\frac{\sin (x/k)}{x/k}dx$$ By definition, Sinc[x]=Sin[x]/x therefore ...
132 views

### Creating a Block from a list of rules

How can I create a function which works like Block but takes a list of rules as its first argument, rather than a list of assignments? The function needs to be ...
97 views

### Detect when InputField gets keyboard focus

How might I detect when an InputField comes into focus? For example ideally something like this would work. ...
401 views

### Share experiences, preferably the surprising ones, with using ItoProcess

Can people please share their experiences, preferably the surprising ones, with using ItoProcess? I am a big fan of ItoProcess and have already used it for several finance-related tasks, though I ...
285 views

### How do I overlay corresponding values over each frame of an animation?

I recorded a phenomenon using video capturing (phen.avi, imported into Mathematica) and simultaneous measurement of some electrical properties of that phenomenon (a ...
511 views

### Problem with SerialIO package and Lego NXT

I'm following a guide from The Mathematica Journal that describes how to use Mathematica with the Lego Mindstorms NXT but have some trouble getting started and got stuck with the SerialIO package. I ...
334 views

### How to punch a hole in some 3D distribution of points

Suppose we have a long list of 3D Cartesian coordinates, defining a distribution of random points in 3D space. How could we remove all the points inside a sphere of radius ...
772 views

### Monte Carlo simulation using geometric Brownian motion

I'm relatively new to Mathematica programming, so forgive my rather unsophisticated question: I'm trying to do a Monte Carlo simulation using geometric Brownian motion (GBM). I want to write a ...
189 views

### How to create a “standard” CDF programmatically?

How can I programmatically create a CDF which is similar to the CDFs created by File -> CDF Export -> Standalone...? ...
780 views

### How can I recreate Trott's Riemann Surface plot in Mathematica?

In reading Michael Trott's Visualization of Riemann Surfaces of Algebraic Functions, he has: ...
273 views

### A good way to manage code in a complicated CDF?

When doing complicated programming in a Mma notebook I define several functions that I use in my higher level funtions, and I use a "Subsection" cell for each definition. For example I might write: ...
329 views

### Using “Raw MathLink Connections” to create a “Kernel Object”

Mathematica 8.0.0: I am stuck trying to get a Mathematica Mathlink connection from my Windows computer working that should connects to Linux over network (or vice versa) and then launches a Kernel on ...
1k views

### Determining the RGB values of the default plot color

In Mathematica 7, the default plot color is a purple-like color (although I think it is not Purple). Is it possible to use Mathematica to determine the RGB color ...
332 views

### Extracting parts of nested lists of rules using a syntax similar to JsonPath or Xpath

Given an example data set: ...
176 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 ...
458 views

### How do I make NotebookEvaluate work inside Button?

The following creates a button to select a notebook to run. When the button is pressed it seems that Mathematica finds the notebook but cannot evaluate it. The following error occurs Could not ...
372 views

### Attaching persistent assumptions to symbol definition

Is it possible to attach assumptions to a symbol? This relates to this question. Most of my work involves physical equations, i.e. there are basic assumptions on variables that will always hold true ...
2k views

### How can I connect to a database using the 32 Bit ODBC on a Windows 7 (64 Bit) machine?

I am having difficulties using a DSN that was defined in the 32 Bit version of the ODBC-manager? (there are two separate managers for 32/64 Bit on a 64 Bit machine) Using the DatabaseLink package ...
144 views

### Poincaré map for dynamic billiard

There's a very nice demonstration of dynamic billiard written by Dan S. Reznik that can be found on demonstrations wolfram: here I was thinking whether it would be possible to draw the Poincaré map ...
95 views

### How to deal with the condition $u_i=u_{i+1}$ in B-Spline basis function?

The defintion of B-Spline basis function as shown below: Let $\vec{U}=\{u_0,u_1,\ldots,u_m\}$ a nondecreasing sequence of real numbers,i.e, $u_i\leq u_{i+1}\quad i=0,1,2\ldots m-1$ N_{i,0}(u)= ...
215 views

### Is it possible to assign different colors to parts of an .obj file?

There are four different cubes in an .obj file. After loaded into Mathematica, is it possible to assign four random colors to the cubes? ...
146 views

### Example of Integrate applying a numerical evaluation N

Here is a minimal example: Integrate[(a[1] + x)^2, {x, 1., 2.}] 2.33333 + 3. a[1.] + 1. a[1.]^2 The problem is that ...
146 views

### Is there a faster way to Map an Association?

Consider mapping an existing Association in a manner such as this: ...
252 views

### Mathematica 10 fails to calculate integral that Mathematica 9 can handle

The following: ...
145 views

### Construct a function that can generate a geometry by extruding a section

Toady I want to construct a geometry shown as below: I know the Mathematica has the functions like Cylinder, Sphere and so ...
229 views

### Problem regarding 3D plot of a Moebius strip from a set of 2D points

First time posting here, although an experienced user of WM. I have a problem regarding graphics which I cannot seem to fix, so I am asking for your help. I start with a set of points $(x,y)$ in the ...
166 views

### calling CUDA library functions

Mathematica has some predefined CUDA functions, like CUDAMap, CUDAFourier, etc. My question is how can one call functions which are part of CUDA library but not part of predefined Mathematica ...
91 views

### How to enforce numerical precision throughout a package

I developed a big package that does quite a bit of numerics. Is there a way to enforce that all numerical computations are done with a pre-defined accuracy? For example, can one use something like ...
863 views

### Select a repeated element in a list

I want to select all elements that repeat 4 times in the list. I propose this code ...
415 views

### How to display each step of an A star algorithm?

I wrote a pathfinding program: A*, which is an extension of Dijkstra. I want to see the result of each step at a time. Which function should I use? The main program is the notebook Astar, which is ...
348 views

### Plotting: Is anyone familiar with gradientfieldplot command?

I am trying to plot this graph showing the electric field lines and lines of equipotential based off the electrode configuration(in black) of two parallel lines. This is what I've been using for other ...
160 views

### how to improve efficiency when I want to classify a list according to certain laws

I have a function that generates lists: f[n_] := Join @@ Permutations /@ PadLeft@IntegerPartitions[n]; For example f[3] ...
297 views

### What is the fastest way to replace all zeros in a matrix?

In the following matrix m every 0 should be replaced with a 1: m = {{0,1,2},{5,0,3},{8,0,0}} Desired result: ...
197 views

### Embedding StreamPlot in Graphics3D

I am trying to visualise the action of the infinitesimal generator of a Lie group on the solution of a 2-ODE system drawn in the 3D space (t,y1,y2): t is time and y1,y2 are the two dependent ...
492 views

### Clustering 3D Data Points on a Periodic Cubic Grid

I have a set of 3D data points on a cubic grid. The data can be downloaded from here https://skydrive.live.com/redir?resid=F96524B72DCD75FB!14240 and read into a variable ...
229 views

### Setting a Counter in Mathematica Notebook

I would like to write a book using Mathematica, but I will write one chapter on several files. How to tell Mathematica that the BookChapterNumber pointer has the ...
199 views

### Parallelizing or optimizing a script for calculating the size of all pairwise intersections between collections of sets

I need to speed up or parallelize an operation that looks essentially like this: ...
278 views

### How to disable differential styles/markers/etc. for multiple entities?

For functions that can produce multiple "style-able" entities, Mathematica by default will give each such entity a different style. Similar conventions apply to other features, either by default, or ...
358 views

### How to add new nodes to an existing graph with fixed (coordinates) nodes?

I'm ultimately trying to create a directed graph with some of the nodes in fixed positions and the other nodes placed around them in "acceptable" positions. It's better if I ask the question by ...
239 views

### Switching among view points in a Manipulate expression

Edit: Some additional viewpoints were included to make it easier to test. Here's code for an alternative function, the graph of which is a bit less symmetric. Feel free to use either code set: ...
2k views

### How to find the Shortest Path, visiting ALL vertices, without coming back to the start (Hamiltonian Path, minimum distance)

A car has to pick up each person and take them to their destination. I am trying to find the shortest tour that will do this. How can I find the shortest path between any s and t.... visiting all ...
214 views

### Assign variables automatically to a function

Lets consider that I've this function: fn = a*x^2 + b*x + c; The idea here is to assign automatically the variables a, ...