7
votes
1answer
110 views

Why does Rescale performance vary significantly based on the real number values in a list?

I have a list of the form: testList = Table[{Flatten[RandomReal[{-200, 200}, {1, 2}], 1], RandomReal[{-200, 200}, {69, 2}]}, {i, 1, 100}]; And I would like to ...
3
votes
2answers
128 views

Creating a trigger to update a previous ListPlot output with new data

Imagine I'm running a loop that's manipulating and changing elements in an array. Is it possible for me to create a ListPlot output in my notebook that updates on ...
7
votes
0answers
163 views

Finding hidden treasure (aka finding undocumented functions) [duplicate]

I was searching for a way to determine if a point is within a polygon and stumbled upon rm -rf's answer. (actually, I really wanted to find a point within a ...
6
votes
1answer
721 views

How do I calculate Standard Deviation confidence intervals in Mathematica?

I have a series of simulation results and I would like to demonstrate how the confidence interval for the mean and standard deviation decrease as the number of results increases. I have done this for ...
2
votes
1answer
826 views

How to show factorial in expanded form with variables

When evaluating the following (Factorial[n + 1]/Factorial[(n + 1) - (k + 1)]) with Mathematica 9, the result is sent to output as ...
6
votes
2answers
1k views

How to find the non-differentiable point(s) of a given continuous function?

For example, the non-differentiable point of the function $f(x)=|x|$ is at $x=0$. How to find the non-differentiable points of a continuous function that is defined numerically?
4
votes
2answers
787 views
11
votes
1answer
727 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
539 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 ...
12
votes
1answer
378 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
213 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
3k 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
986 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. ...
4
votes
1answer
112 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
353 views

Vertex Labeling Problem in a Graph

I am using following codes to create a graph. ...
2
votes
1answer
119 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: ...
1
vote
1answer
612 views

Custom ticks failing with Frame

I know I can manipulate ticks: ...
14
votes
1answer
570 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
496 views
7
votes
2answers
746 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
226 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
697 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
74 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
271 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
271 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
185 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
127 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
128 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
94 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
333 views
4
votes
2answers
170 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
124 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
153 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
131 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? ...
19
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
165 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 ...
12
votes
5answers
615 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
195 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
182 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
105 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
461 views

How to debug error triggered by replacement rule?

The second line below produces the errors shown: ...
0
votes
1answer
202 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
735 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
134 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
440 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: ...
0
votes
0answers
150 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
287 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: ...

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