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149 views

Is there a way to add arrows along a parametric curve inside a manipulate function? [duplicate]

I cannot find a good way to add arrows along a parametric curve that I used NDSolve to get. I have written everything inside ...
5
votes
1answer
176 views

How can I compile function with Apply?

For example, I tried to compile this function but Mathematica gives "The only function arguments supported are Times, Plus, or List", I have no a way to compile this. ...
1
vote
0answers
45 views

“Go back” and “Go forward” in help? [duplicate]

This is a duplicate question with Gestures for forward/backward in help browser (particularly on a Mac). Please close this question. In IE, we can "go back" by Alt+←, and "go forward" by Alt+→. This ...
1
vote
1answer
1k views

How to make Graphics3D object with different colors

Here is a sample Graphics3D object: ...
2
votes
0answers
148 views

Need an explanation on how code from journal works

I was reading a paper from Mathematica Journal. It gives code for calculating subsets. ...
8
votes
2answers
251 views

Is it possible to find a CellularAutomaton behind a sequence of 2D Tables

Maybe this is a hard question, maybe not. Whoever knows the answer can help me a lot starting working on CA theory. Let's suppose I have a sequence ...
0
votes
1answer
74 views

Function that displays set of integers fulfilling constrictions

I would like to make a function of three parameters $i$, $j$ and $k$ that displays a list of integers fulfilling some criteria. Specifically the set of integers is: $\zeta_{ijk} = \Big\{p\in\{2j+2,2j+...
2
votes
2answers
718 views

Image Restoration

I want to degrade the image, and then execute the restoration, such as a lena.jpg. I tried this: ...
0
votes
0answers
81 views

NMinimize and FindRoot Issues with System of Equations [duplicate]

I am trying to solve a constrained optimization problem with a system of transcendental equations and am running into issues with NMinimize. I have a system of equations (...
4
votes
1answer
230 views

How can I test properties of a symbol without unwanted evaluation

Problem How to get the head, size, dimensions, etc. of a symbol without evaluating it? Since Mathematica does not allocate fix storage space and type to symbols it is not trivial to query runtime ...
8
votes
3answers
2k views

How do I find the intersection of a closed 3D curve given by numerical data with a specified plane?

I have a list of 3D data points which form a closed curve. My own data can't be easily generated analytically, but the qualitative behaviour is well represented by a parametric curve families such as <...
7
votes
2answers
2k views

Animated Vector plot

I'm trying to make an animation of a time-varying 2D vector field. However, I'm got a difficulty in that Mathematica normalises the length of the vectors with each call to ...
0
votes
2answers
585 views

Seeking faster method than using Table and If together [duplicate]

See the example below. Is there any way to make this execute much faster and still get the same output ? I have read Conditionals slower than operators? but it didn't really help me as I can't seem to ...
1
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0answers
343 views

Conditional solution for system of linear equations

I have a linear equation system Q.m = t, with m unkown and where Q has dimensions ...
1
vote
2answers
997 views

How to place Plot Information within a Text box on top of a Bar Chart?

How could I place a text box on the top of a bar chart where the top line would have a larger font size than the second line? My Data: ...
4
votes
1answer
680 views

How to determine cluster membership using FindClusters?

I have a 1000 by 3 data matrix in which for each person we have 3 scores. I want to cluster those persons into 8 cluster using Agglomerative method. I did the clusetring by: ...
8
votes
2answers
1k views

How to add equations' left and right sides together?

If we have two equations E1 and E2, and instead of using Solve to solve it, we simply need to manually add them up which would allow some simplification that could ...
2
votes
0answers
265 views

Problems with Simultaneous Equation Solving

Let me first explain what I am doing and then I will explain the problem that I can't figure out. I am basically trying to solve 2 equations for 2 unknowns (a1 and <...
8
votes
1answer
309 views

FullDefinition and Module local variable

I have a question about FullDefinition and how it interacts with the local variables of Module. I've created a few functions (...
0
votes
1answer
833 views

Hue-like Legend spectrum with bright colors for a plot

I use Hue to color ArrayPlot: ...
7
votes
1answer
456 views

Exporting large numbers in WDX format

Bug introduced in 9.0 and fixed in 10.3 I have a list of 10 000 3×3 matrices in Mathematica. The entries are rational numbers. I would like to write this to a file so I can load it again in the ...
0
votes
0answers
43 views

Keeping memory to reduce the running time of recursion [duplicate]

I am using the following recursion in Mathematica to compute W[n, 1, s] for given n and s: ...
3
votes
4answers
426 views

How to improve the quality of the ListPlot output

I need to plot massive data stored in external ASCII files. Below is the Mathematica code I use for this job: ...
13
votes
1answer
2k views

What does ` symbol in ClearAll[“Global`*”] mean?

I have found an example for clearing all symbol definition by: ClearAll["Global`*"] But what does the symbol ` mean? It isn't the apostrophe ', yet it is not ...
5
votes
3answers
1k views

Getting RGBA data from an image

What is going on with returned data in the following examples? It appears ImageData returns different types depending on the what data is passed into ...
3
votes
1answer
126 views

Generating Palindromic_number [duplicate]

I'm trying to construct Palindromic_number, I came up with this code: ...
3
votes
1answer
244 views

Real integral evaluating as indeterminate

Mathematica evaluates the following integral as: ...
14
votes
11answers
726 views

How can I generate a nested array like this one?

Well, this is how the array looks like: I came up with this code: n = 10; Nest[ArrayPad[#, 1, 1 - #[[1, 1]]] &, {{1}}, n] /. {1 -> "*"} Any better ideas?
1
vote
2answers
489 views

Finding normals to a curve through a given point

I want to find x on curve $y(x)$, where curve $y(x)$ is perpendicular to point $(x_0,y_0)$. for this I minimize the distance between points $(x,y(x))$ and $(x_0,y_0)$, here's an example for point $x_0=...
3
votes
2answers
599 views

Modify all the second elements of every pair in a list of pairs

I have a list in the form {{a, 1}, {b, 2}, {c, 3}}. Let's say I want to operate a transformation on all the second elements of each sublist, but this transformation is a function of them all together....
24
votes
4answers
6k views

Plotting a contour on a torus

There are two ways to consider a two-dimensional torus. One way is to take a parallelogram (let's say the square $[0, 1]^2$) and topologically glue the opposite edges. Another way is to look at the ...
17
votes
1answer
359 views

Dynamic and LibraryLink: dynamic visualization of a simulation

I am asking this question to save some time and I am expecting answers only from people who have tried something like this before. (I realize that I could just try it and see if it works, but that ...
8
votes
3answers
2k views

How to connect Mathematica 9 to MS SQL 2012 using Windows 7 enterprise (64-bit)

I have used Microsoft Open Database Connectivity (ODBC) with Mathematica 8.0 and MSSQL 2008 on Windows XP, but I can't get it to work on Windows 7 Enterprise (64-bit) with Mathematica 9.0.1.0 and MS ...
11
votes
1answer
123 views

When is the output of examples in function documentation rasterized?

Upon building documentation in Workbench, Workbench sometimes converts the output of examples on function pages into rasterized images, and sometimes not. Does anybody know what controls this behavior?...
15
votes
4answers
666 views

FindShortestTour for charity (or: How can I optimize meal delivery with FindShortestTour?)

I've been wondering about this for a while - but never got around to asking - until I saw faleichik's incredible answer to Mathematica Minecraft. I did some work at a not-for-profit a little while ...
7
votes
2answers
2k views

Why isn't autosave enabled by default?

While I've come across several ways to implement/enable autosave (see: Is there a notebook autosave frequency configuration?, Saving my code before cell evaluations: Insurance against front end ...
4
votes
1answer
2k views

Excel DDE Link: reading and writing in real time

I'm wondering if it is possible to link Excel and Mathematica in real time, so that Mathematica can be used as a computing and "storage" tool. Suppose I have an Excel spreadsheet with an active DDE ...
6
votes
2answers
1k views

Transcendental equation with ContourPlot3D

I am still a newbie to Mathematica, so I am still getting used to the syntax and logic of the program - but I've been trying to do the following 3D plot: ...
2
votes
0answers
141 views

Disagreement between FindGeoLocation and Alpha: “Where Am I?”

While trying to estimate a user's location in a notebook, I noticed that FindGeoLocation[] was extremely inaccurate. I realize that it uses an IP lookup to make ...
5
votes
1answer
916 views

Wallis Formula and Pippenger Product---How do we get symbolic output?

The Wallis Formula computes $\frac{\pi}{2}$ OEIS and the Pippenger Product computes $\frac{e}{2}$ OEIS. Here is a combined formula: ...
1
vote
1answer
139 views

Memory handling by ConstantArray

I noticed the following issue when using ConstantArray: a = ConstantArray[0., {10000, 100}]; ByteCount[a] (* 8000152 *) Then ...
20
votes
1answer
1k views

xkcd: Geohashing in Mathematica

On May 21, 2008, an xkcd comic proposed a method for creating a random, local meeting place that can't be determined until the day of the meeting. This method is usually used for xkcd fan events, but ...
18
votes
6answers
1k views

How do I replace a missing value in a column with the value immediately above throughout a table?

I have a large table (7000 rows × 17 columns) of terse textual data. In many of the columns, empty entries have been replaced with "." as a marker. Working from the top of the columns downward, I want ...
6
votes
1answer
845 views

Building a molecule viewer: aesthetic rotations

I am working on building a molecule viewer in Mathematica and am running in to problems with controlling rotation of the molecule (which is rendered as a Graphics3D...
0
votes
1answer
140 views

Counting Stochastic Processes and displaying relative value

Counting Stochastic Processes and displaying relative value I have two watermarks and multiple stochastic processes given. I want both to display and count the stochastic processes which are below ...
0
votes
1answer
352 views

Can I take derivative of a function that represents a piece of music?

Can I take the derivative of a function that represents a piece of music? The music is given in .mp3, .midi or whatever comes in handy.
2
votes
1answer
151 views

Is it possible to create a styled cell with pre-defined content?

When you create a new styled notebook from the Stylesheets chooser dialag, you get a new notebook using the chosen style with some sample content provided. But if you apply styles from the same ...
15
votes
1answer
598 views

WhenEvent and partial derivatives

Can WhenEvent be used to reset the conditions on a PDE at a given time? How would the syntax of that be? This is the code I`m using ...
9
votes
3answers
984 views

Simplifying the trace of a matrix expression

I have a long expression involving matrices that I derived using the NCAlgebra package. Can I simplify the trace of the expression? For example, say b is a scalar (...
16
votes
7answers
2k views

A function that accepts a pair or a list of pairs

Probably a duplicate, but it's not easy to search on "lists". I have a function that accepts a list of lists, say {{a1, b1}, {a2, b2}, {a3, b3}} and performs some ...

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