0
votes
0answers
4 views

Deformation of a piture

If I get a picture, and imagine it as a complex plane, then given a function how to visualize the resulting deformed picture?
0
votes
0answers
11 views

How should I do to Return a value to a multi-line function? (functional programming)

Minimal Question as resume of my dude (explained after line 10) . Solving this is enough for me: ...
0
votes
0answers
3 views

Questions about CountryData

a. What is the proportion of Internet users to population in the United States? I am really confused. I don't where to get these information from and how to set up the proportion. b. What countries ...
0
votes
0answers
15 views

How to switch elements i,j in a list? [duplicate]

Are there any direct function to switch elements i,j in any list? or is necessary to create one with Do / If ? (I don´t ask for making me this function if it doesn´t exists) My target is can ...
1
vote
1answer
18 views

Visualization of matrix transformations

I define the "matrix transformation" here as follows: $\left[ \begin{matrix} x_1' \\ x_2' \\ \end{matrix} \right]=\left[ \begin{matrix} a & b \\ c & d \\ \end{matrix} ...
5
votes
2answers
45 views

Nothing appears in simple plot

I'm trying to get the following simple code to work. (The code is just supposed to graph the norm of the second derivative of a vector function). ...
5
votes
2answers
984 views

Difficulties with Importing PDFs in Mathematica

I am trying to import a group of PDFs that I have downloaded (it is in the realm of 1,000+). They are a group of doctoral dissertations that I'm trying to automatically extract bibliographic ...
0
votes
1answer
15 views

Questions regarding DictionaryLookup of Mathematica

a. Make a function longest[lang_] that gives the length of the longest word in the dictionary of lang. You should get ...
2
votes
2answers
169 views

How can I calculate the limit without using the L'Hopital's rule

I need to prove this limit without using the L'Hopital's rule: $$\lim_{x\to 0} \frac{(1+a\,x)^{1/4} - (1+b\,x)^{1/4}}{x} = \frac{a-b}{4}$$ How can I do it in Mathematica?
0
votes
0answers
21 views

Find lengths of contours in a ContouPlot

I am trying to find the lengths of different contours in the following plot: It is a complicated piecewise function evaluated on the unit disk. I am hoping there is an easy, generalized way to ...
1
vote
1answer
30 views

Butterworthfilter data filter

I am currently doing a signal analysis and filtering using Matlab. The filter I am using is Butterworthfilter model to filter scattered data (vector data). I am using Matlab as follows: ...
1
vote
1answer
179 views

Why doesn't FullSimplify work properly on this?

I wish to simplify the simple expression fac[n_] := Sum[R^i, {i, 0, n}]; as much as possible for various $n$. FullSimplify or ...
0
votes
1answer
22 views

load static library (.lib) using NETLink

is it possible to load static library (.lib) compiled in c++ using NETLink or similar in Mathematica?
3
votes
2answers
74 views

Different colors for nodes in tree plot

I have some list of numbers which I am plotting using TreePlot. This is the code: ...
7
votes
2answers
93 views

Measuring curve length on a binarized image

With the help of almighty Mathematica 9, I got from this To this: with this code: ...
2
votes
1answer
149 views

How to apply a free-form input Function using InputField

I am trying to take a free-form input Function to create a list using NestList. ...
1
vote
0answers
26 views

Why does Network`GraphPlot`wrapper appear in my GraphPlot?

I'm making a GraphPlot of data similar to this: ...
1
vote
2answers
82 views

Few quick Mathematica questions about Dictionary

a. Get the list whose elements are of the form {language,number of words in dictionary) I tried this, and it gave me the number if words in dictionary, but I don't know how to get the language part: ...
8
votes
4answers
334 views

Filling a curve between a line and the x-axis

I'm trying to plot the function $f(x)=\dfrac{1}{x^2}$, filling the square area from (0,0) to (1,1) with purple and filling the area under the curve from 1 to 4 with red. However, Mathematica is not ...
0
votes
0answers
33 views

Fold Dynamic Function

I'm making on a demo working with differential equations as functions of two variables (x and y). The demo will have to Fold the differential equation with an initial y-value and a series of x-values. ...
0
votes
0answers
29 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 ...
5
votes
4answers
89 views

ContourPlot refuses to show in-figure PlotLegends after turn on ContourShading

I would like to do a contour plot with a label inside the figure. For example, the following works well. Note there is a small "example" at the right bottom figure. ...
16
votes
3answers
309 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
78 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
207 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
74 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
34 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
28 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
100 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
69 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
123 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
92 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
51 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
106 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
24 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
187 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
54 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
39 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
59 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
63 views

Using KalmanFilter or KalmanEstimator

I have the following: ...
0
votes
1answer
28 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
35 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 ...

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