0
votes
0answers
33 views

How can I include a popup menu in my wizard's content?

I'm trying to create a wizard that enables the user to choose between different shaft components. At the same time, I need a flag to be 1 if he chooses a bearing and 0 otherwise. I extended the ...
16
votes
3answers
312 views

Undocumented form for Extract

Prompted by a comments conversation here, here's an interesting (and often performance enhancing) use of Extract: ...
5
votes
1answer
97 views

Why does Arrow not work well with Scaled coordinates in 3D?

I am a little puzzled by the fact that if I try to use Arrow with Scaled coordinates in 3 dimensions the arrowheads are all over ...
3
votes
0answers
210 views

Transform recursion for coefficients into differential equation for generating function

Assume, one is given a linear recursion with polynomial coefficients for a sequence $(a_i)_i$, such as a[i] == i a[i-1] I would like to convert this recursion ...
3
votes
2answers
85 views

Import multiple files from folder in order of date added

I have a folder that contains certain files I want to import. In my case those are .png files. As all the files I want to import contain the phrase "accum" in their filenames, I can use ...
0
votes
0answers
36 views

Simple propability issue [on hold]

I have a simple problem: I have 16 kitties. There is 1/2 chance to get a male and 1/2 chance to get a female. What is the probability to get at least a female? Then, if 10 kitties die, what is the ...
1
vote
0answers
32 views

ImageCapture on Windows 8.1

I have an Asus SmartTab tablet with Mathematica 9 on it. When I run ImageCapture, nothing shows up in the image window. Originally running this completely crashed ...
2
votes
2answers
105 views

Solving simultaneous exponential equations

In[1]: Solve[{(1 + k)^n == 0.6, (1 + k)^(n + 1) == 0.3}, {n, k}] Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; ...
0
votes
0answers
73 views

Calculating the Lyapunov Exponent/Spectrum for the Duffing Oscillator

Some fellow students and I are trying to calculate and plot the Lyapunov spectrum for the Duffing oscillator (currently a test approach). Each of us has Mathematica knowledge based purely on past ...
2
votes
2answers
126 views

region plot in a 2-simplex

I want to plot a 2-dimensional region with constraint $x+y\le N$, i.e., I want to plot a sub-region inside a 2-simplex. As an example: ...
5
votes
1answer
97 views

How can I get this Graphics3D to rotate around a particular sphere?

I made this Graphics3D of the Sun with the plotted orbits of a few astronomical objects. ...
4
votes
2answers
53 views

Document Creation: inserting a grid

This question is strongly related to: NotebookWrite Cell with Grid Let’s create sample chart ...
0
votes
0answers
45 views

Automatic method for NDSolve [duplicate]

How can I understand which method Mathematica automatically chooses to use for numerically solving the following two equations? 1: ...
0
votes
4answers
108 views

RSolve fails on a two-equation non-linear system

I have a system of just two recurrence equations, I need to solve them and so I use RSolve: ...
1
vote
0answers
25 views

Is there a way to convert InlineCell to InputForm once and for all?

After asking a question about making InlineCell similar to Input, I realized that by typing Shift+Ctrl+I I really can manually convert every InlineCell to InputForm. So my new question is: Is there a ...
265
votes
12answers
45k views

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ...
6
votes
1answer
189 views

If doesn't compile if its output is the output of Compile?

The smallest sample I can find to reproduce this problem is: test = Compile[{}, If[True, 1]]; << CompiledFunctionTools` CompilePrint@test ...
0
votes
1answer
55 views

SplicedDistribution - different definition across Mathematica 9?

I am having troubles with my notebook. I succesfully defined Asymmetric Laplace Distribution at school using SplicedDistribution function, and Mathematica was able ...
0
votes
0answers
22 views
0
votes
0answers
40 views

How to get integer/rational and real eigenvectors to be the same? [duplicate]

forgive me if I missed this already being answered or too easy. Given a matrix: q = {{1, 3, 5}, {7, 11, 13}, {1/3, 1/7, 1/13}}; Eigenvectors are different here: ...
6
votes
3answers
194 views

Map structure of irregular list, Flatten then reconstruct list using structure

I'm trying to use Compile[] to improve the performance of an algorithm. The algorithm works on a set of matrices which are not of a similar shape. Unfortunately ...
2
votes
1answer
41 views

How can I make a stylesheet where inline cells have are styled like input cells?

How can I make a stylesheet where inline cells have are styled like input cells? By "similar", I mean the same font and syntax highlighting. I have even tried copying all settings from ...
0
votes
0answers
70 views

Mathematica function Det has unexpected behavior

I am using Mathematica "Kernel" -> {"Version" -> "9.0 for Microsoft Windows (64-bit) (January 25, 2013)", "ReleaseID" -> "9.0.1.0 (4055652, 4055188)" on a Win 7 machine. The file listed below uses ...
0
votes
1answer
62 views

Can ParallelDo speed up a counting problem?

How to make parallelize the following code keeping the same "idea". The example I have in mind is more complicated, but I would like to know if a program of this structure can be parallelized? ...
2
votes
0answers
68 views

Using KalmanFilter or KalmanEstimator

I have the following: ...
0
votes
1answer
31 views

Help with Reduce, quadratic system of inequalities

I'm trying to obtain an equivalent system of inequalities to the one below but without the variables x and z. Somehow Reduce just repeats the command. ...
2
votes
1answer
96 views

Determining the dimension of a probability distribution

Functions like Mean and RandomVariate clearly infer the dimension of the distribution passed to them. One can also usually ...
0
votes
3answers
74 views

Removing a ProgessIndicator when no longer needed

I have a progress indicator in my Mathematica notebook that I update as various calculations are performed: indicator = ProgressIndicator[Dynamic[progress]]; I ...
0
votes
0answers
36 views

What does K[1] represent? [on hold]

I am trying to solve this recurrence relation: RSolve[a[n]==k*a[n-1]+t[n], a[n], n] Mathematica returns: $\left\{\left\{a(n)\to j^{n-1} \left(\sum ...
7
votes
1answer
493 views

How to map rotate, pan, zoom to manipulate controls

I am wondering if there is a way to restrict the motion of the rotate mouse cursor in when moving around a 3d plot. For example, I want the y direction of the cursor to correspond to pulling the z ...
1
vote
1answer
62 views

How to specify the centre or PlotRange of a Graphics3D?

When I create a Graphics3D, I often want to place an object right at the centre of the box. Initially I thought that the centre was specified by ...
0
votes
1answer
69 views

Generate a list of values with equal number of each value

I want to create a list of 32 values such that from {a,b} I can generate ...
10
votes
1answer
179 views

Bizarre behavior of With, Compile and Break

I'm guessing this is almost certainly a bug in Compile (because they're fairly common), but it's pretty weird and I spent about an hour tracking down the issue and ...
-1
votes
0answers
50 views

How to generate all symmetric positive semidefinite 0,1 matrices of a given order [on hold]

The title says it all. There are many instances when we need to check some properties of such matrices. I am looking for an efficient code.
26
votes
5answers
1k views

Identifying critical points of 2/3D image/cubes

Upshot I am interested in identifying critical points of a 3D field/cubes (maxima, minima, tube-like and wall-like saddle points) and 2D field/image (maxima, minima, saddle points). I.e. the ...
0
votes
1answer
46 views

looping in mathemtaica for using the current value as initial state of next value [on hold]

i have some initial state $psi[x,t]$. I perform some operation on it and store the value in another state $pi1[x,t]$. Now on the next step i have to use $psi1[x,t]$ as initial state and perform the ...
0
votes
0answers
11 views

Showiing that matix is an eigenvector? [migrated]

Let A= a b c d be a 2 x 2 matrix, where a,b,c and d are real numbers. We say that A admits an eigenvector if there exists a unit vector u and a real ...
6
votes
0answers
68 views

HighlightGraph and Hyperlink

In the documentation of Mathematica it is mentioned that you can use Hyperlink and Tooltip as wrapper in a similar manner as ...
0
votes
0answers
66 views

complicated Numerical Integration, FEM application

I am trying to calculate a 2d Integral which has another 2d integral in the integrands. here is the setup: ...
0
votes
1answer
66 views

How to get more accurate orthonormal eigenvectors?

I have a matrix M with real entries in MachinePrecision. I compute its eigenvectors and construct matrix ...
0
votes
1answer
40 views

Pattern matching with PDF, Distributed and multivariate distributions

I have defined a function to compute the Shannon entropy of a probability distribution: ent[p_] := Expectation[-Log[PDF[p, x]], x \[Distributed] p] This works ...
0
votes
0answers
21 views

Optimizing FindInstance for large systems of Diophantine equations [on hold]

I have a system of Diophantine equations, with about 15 equations and 25 unknowns. To find at least one solution to this system I can use FindInstance and specify the domain to be Integers. But in ...
0
votes
1answer
76 views

Plot Notes present in sound sample

I would like to visualize a sampled sound, and place the sounds as notes starting from C0 to A8 or such. I have a table of ...
6
votes
2answers
159 views

Scan vs Map vs Apply

I cannot understand the difference between Apply, Scan, and Map. I have tried to play with ...
14
votes
4answers
723 views

Converting a large floating-point number to a single-line string

When I feed a large (or small) enough floating-point number to ToString, it produces a two-line string, with the first line containing only the exponent of 10: ...
7
votes
1answer
131 views

How to change the appearance of a group opener?

I would like to change the GroupOpener appearance. In the present Mma design it is too small and can be missed by a reader unfamiliar with Mma. I know, how to change its color through the ...
1
vote
1answer
54 views

How do I use Subgraph to sample the $n$ vertices of a graph with the greatest connectivity?

Let $G$ be an arbitrary graph with some number of vertices $||V||$ and some number of edges $||E||$. We can use Subgraph to generate, well, a subgraph of ...
0
votes
1answer
80 views

Create new file, based on 500 articles

I've got a folder with 500 newspaper articles. Each article is saved in a seperate file with a number in the title like "1.txt", "2.txt". Each article has a date but it is not clear in which line the ...
4
votes
1answer
68 views

What string pattern will match $n$ contiguous characters drawn from a given alphabet?

I'd like to use StringCount to count the number of subwords in a string that have the form **** where ...
0
votes
1answer
26 views

Open a pre-existing CDF file from a stand-alone CDF file

This is related to my previous question here A series of my questions are related to an important problem: It is important to be able to CDF-publish a document, and be able to open a separate ...

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