11
votes
1answer
840 views

Example program for calling Mathematica from C

I want to call Mathematica from a C program. Suppose I have two numbers x = 2 and y = 3. I want to define ...
8
votes
3answers
619 views

Create sine function with random increase in phase

I am trying to simulate a signal that randomly increases its phase, so far I have tried two thing but neither worked. I usually use matlab but I want to learn some Mathematica so I thought I would try ...
13
votes
1answer
460 views

Can Manipulate controls have the option Appearance -> “Labeled” by default?

I was wondering if there's a way to tell Mathematica to use the option Appearance -> "Labeled" for all Manipulate commands by ...
4
votes
1answer
241 views

How to change the aspect ratio with drawing tool?

I'm drawing an image in editing an slide show with the drawing tools. But the aspect ratio of the created drawing seems fixed and not changeable with mouse dragging the border and corner as in other ...
6
votes
2answers
4k views

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

I have a function f(x,y,z) of three variables and some constants: ...
12
votes
1answer
1k views

Solving Killing equations

Is it possible to solve Killing equations in Mathematica for a general vector? I am looking for a way to create Killing equations and then find what the vectors are, but I have a problem with this. ...
5
votes
1answer
114 views

Error from BoundedDiagram

I cannot understand the meaning of the error BoundedDiagram::notuniq: BoundedDiagram requires that boundary vertices lie in unique Voronoi polygons. >> BoundedDiagram::nobd: Bounded ...
3
votes
1answer
436 views

Vertex Labeling Problem in a Graph

I am using following codes to create a graph. ...
2
votes
1answer
121 views

Can Map operations be compiled or otherwise sped up for large lists?

I'm performing a series of Map operations in the following script: ...
2
votes
1answer
722 views

Custom ticks failing with Frame

I know I can manipulate ticks: ...
14
votes
1answer
640 views

Size distribution of nanoparticles from a transmission electron microscopic image

I have found a research article about Martian sand grain size determination from the image using Mathematica (Figure 2 in the linked article). They have not provided any detail of the methodology. It ...
2
votes
1answer
622 views
7
votes
2answers
873 views

Voronoi Diagram: Displaying site specific color in a voronoi diagram

I am using Voronoi Poligonization as a support form simulating island erosion; my data are the output of VoronoiDiagram, ...
1
vote
2answers
248 views

How to apply function f for each time value t, to each pixel from image, resulting in t images

I have a 2D array of complex values and I want to apply a function to every entry of the array, for every timepoint t in a list. I know how to apply my function to one entry for every time t in a ...
3
votes
3answers
868 views

StreamPlot using NDSolve gives error messages

StreamPlot[{x[0], x'[0]} /. NDSolve[{x''[t] == 1, x'[0] == v0, x[0] == x0}, {x, x'}, {t, 0, 1}], {x0, -2, 2}, {v0, -2, 2}] The above code gives me the errors ...
2
votes
2answers
79 views

Constrain movement of Locator (increased t-value)

Continuing with the code at the end this topic, I am now searching for a way of constraining the movement of the locator so that it doesn't "jump" from one "part" of the graph of f to another. So, if ...
10
votes
2answers
173 views

Can I define new graphics directives?

Is it possible to define new graphics directives? For example, suppose I want to be able to use the following code: ...
2
votes
3answers
277 views

Minimization problem

How could you find the smallest constant $c$ that satisfies $$\frac{3^{3k}e\sqrt{3}}{\pi\sqrt{k}\;2^{3/2+2k}} \leq 2^{\;c\;k}$$ assuming $k\geq 1$ is an integer. You can of course take logs of ...
4
votes
1answer
293 views

Creating a function to simplify WolframAlpha query

When I can't remember an integral I usually just query wolfram and have it show steps. This was my naive attempt at trying to make a simpler function. ...
6
votes
2answers
192 views

Get information about a stack of images, without plotting it

A very long time ago I used Mathematica for a few months and found it very intuitive. Now for my work I use MatLab. I was just trying some stuff out with Mathematica again and there is something I ...
-1
votes
2answers
145 views

Palette for pasting matrix templates into a notebook

How I can build a palette of matrices?. So, I would like a palette with a 3x3 square matrix, a square matrix 4x4, 1x3 row matrix, 1x4 matrix row, column matrix 3x1 and 4x1 column matrix.
2
votes
1answer
134 views

Interaction between two sliders that update the same variable

I'm basing this on the code found in the Introduction to Dynamics. I added one more slider which doesn't use the "round and snap" feature given in the link above: ...
2
votes
1answer
103 views

Constrain movement of Locator

Continuing the discussion started in the thread here, I've tried to recreate the code from scratch. I thus looked to constrain the movement of a locator to the graph defined by ...
7
votes
3answers
381 views
4
votes
2answers
176 views

Speeding up Position for finding the indices of a small number of integer elements in a large matrix

I have a large $100 \times 4000$ element matrix composed of integer elements, testMatrix, and I was to use Position to find the ...
2
votes
2answers
132 views

Extracting variables from Hold expression

For example I have some global assignments x=1;y=2;z=3 and an expression Hold[x*y/z]. How can I now extract variables ...
0
votes
0answers
54 views

Construct matrix B from columns of matrix A? [duplicate]

Starting with Mathematica and working with matrices, I am looking for a way to construct a new matrix B from columns of matrix A. For example, matrix a has 8 columns and 4 rows, I want matrix B to be ...
0
votes
1answer
154 views

Generating an array using list values at indices corresponding to entries in a separate list satisfying some criterion

Imagine one has an array of integer value sets that looks like this: ...
11
votes
1answer
147 views

Slideshow mode: how to cycle slides automatically?

I'm doing a slideshow for an informative conference, so I need a slideshow running in background on some monitors. My question is: is there any way to make Mathematica to cycle slides automatically? ...
21
votes
3answers
1k views

Generate a Random Polygon

Does some package exist with a function that takes a parameter $n$ and generates a random 2D $n$-sided simple polygon (convex or non-convex), possibly within a certain bounding box? It does not ...
0
votes
1answer
175 views

johansen test error in code

Cross-posted at the Wolfram community forum I have found this code on a forum, apparently it worked in a previous version of mathematica. Now when I run it, it keeps running for ages. I am not able ...
13
votes
5answers
664 views

How to remove duplicate characters from a string?

How do you remove duplicate characters in a string without converting the string to a list. I want to delete all duplicate characters in a string (i.e. get the unsorted union of characters). For ...
6
votes
0answers
223 views

Does OpenCL/Cuda memory leak if not Unloaded? Problem with allocating/loading GPU memory in Module

The GPU memory manager documentation is not too clear, does GPU memory leak if not explicitly unloaded or if the symbol that holds the reference to the GPU memory gets collected, the GPU memory gets ...
0
votes
3answers
224 views

How to create a discrete 2d slider using existing 2d data?

data = Sort[RandomReal[{0, 1}, {100, 2}]]; Manipulate[pt, {pt, data}, ControlType -> Slider2D] I get a error message: Manipulate::vstype: ControlType -> ...
4
votes
0answers
121 views

Gather dependency on list order?

I get intrigued about Gather behavior on this post. I thought that Gather was invariant under list order? Here is the result I ...
1
vote
2answers
518 views

How to debug error triggered by replacement rule?

The second line below produces the errors shown: ...
0
votes
1answer
253 views

Checking differential equation solution

I have this differential equation: eq=D[ψ[r],r]+A*ψ[r]-(B/(A*r))ψ[r]==0; And DSolve sucessfully solves it: ...
5
votes
1answer
849 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 ...
7
votes
3answers
140 views

How to stop a single function to be evaluated?

See this example: AA = {x} \[Function] Normalize[x] BB = {x} \[Function] Evaluate[AA[x]*5] I need BB to be Normalize[x]*5. Some context:I call evaluate because ...
21
votes
5answers
2k views

How to plot the contour of f[x,y]==0 if always f[x,y]>=0

I've been stuck at this problem for weeks and I've asked several related questions here: ContourPlot shows only part of the contours [duplicate] How to plot the contour of the radius part of a ...
2
votes
1answer
511 views

Avoiding zero (empty set) solution with NDSolve

I'm trying to use NDSolve for a chemical kinetics equation where the rate of conversion is given by this relationship as typed in Mathematica: ...
2
votes
1answer
240 views

step by step interactive indefinite integral

WolframAlpha can give step by step solution for indefinite integral. There seems to be similar question but for derivatives. Is there a way that I can generate my own step by step solution for ...
0
votes
1answer
330 views

Find if element exists in N-dimensional array

I was wondering if there was a more elegant way of finding whether an element exists in an N-dimensional array. The way I would do it is: ...
16
votes
4answers
586 views

Can TreeForm be displayed “sideways”?

One recurrent problem I'm having with displays generated with TreeForm is that the expressions to be so displayed often at least one level with many (> 20) nodes ...
9
votes
1answer
124 views

Why can't I remove the {0, 0} in Circle[{0, 0}] using pattern matching?

Why does Circle[{0, 0}] /. List[_?NumericQ ..] :> Sequence[] return Circle[{0, 0}] yet ...
31
votes
5answers
795 views

How to examine the structure of Graphics objects

One difficulty I'm encountering in studying the structure of Graphics objects is that I have not yet found a way to print or display such structures that are ...
10
votes
4answers
2k views

Function to subdivide interval into n evenly-spaced points

[This post needs better tags than I could come up with. Edits to the tags would be particularly welcome.] I realize that it is trivial to define a function that takes an interval (i.e. two ...
3
votes
1answer
265 views

How to plot the contour of the radius part of a complex function

Suppose we have a complex function $f(x,y)$, in which x and y are real variables. In theory we can write the function into the polar form $$ f(x,y)=r(x,y)e^{i\theta(xy)} $$ where $r(x,y)$ and ...
12
votes
1answer
229 views

Structure of Graphics (esp. those produced by Plot, ListPlot, etc.)

I'm looking for a description of the structure of Graphics objects, aimed at the advanced Mathematica programmer. The motivation for this question is the ...
0
votes
1answer
289 views

String to File removing quotation marks

If I print a string to a file it also adds quotation marks to the string. Here is an example: a = "test \t test" a >> file FilePrint["file"] How can I ...

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