4
votes
2answers
213 views

How to find the variance under the assumption that x follows some probability distribution

I am aware that we can find the expectation under the assumption that x follows some probability distribution, something like this: ...
4
votes
1answer
683 views

Creating a weighted, directed graph from ordered triples

I have a relatively large set of data that I am trying to turn into a weighted, directed graph. The data concerns the inflow of migrants based on country of origin. I currently have three columns of ...
6
votes
1answer
364 views

Multi-column table layout the right way

How do I create book-like multi-column table formatting for a long, narrow tables in a preferably elegant way? Should I be thinking of stylesheets, instead of formatting? I guess this is a solved ...
2
votes
2answers
170 views

How can I create CDF applications which adjust their screen dimensions based on the end-user's display configuration?

I am trying to make a CDF application that takes the user's system information (screen information) and adjusts the size of the application to give a seamless experience over different screens with ...
2
votes
1answer
115 views

ToString in a function

f[x2_] = ToExpression[StringTake[ToString[x2], -1]] x2; f[a3] (*Out: 2 a3*) I expected the output to be 3 a3, but apparently ...
1
vote
1answer
442 views

Problem with Estimating the parameters value of gamma distribution

can anyone please help me with this problem? I am trying to estimate parameters of gamma distribution (fitted into a set of data). Following are my command and the output produced by mathematica: ...
9
votes
1answer
481 views

Efficient export of complex graphics to PDF

So I have 2D plot, made with DensityListPlot. Mathematica just cannot export them properly to PDF, so what I want to do is 1) export the plot itself, without axes, labels, etc, as a jpg image, and 2) ...
-1
votes
1answer
608 views

Need help with solving non-linear differential equation [closed]

I am new to using Mathematica and have a problem at hand: I need to solve $y''(x)+ a \sin(y(x)) = 0$ and plot the output, I need a "manipulate" thingy for the two initial conditions. Help needed.
10
votes
2answers
726 views

How do I map a Mollweide projection onto a sphere?

I have this Mollweide projection of the Earth circa 600 million years ago (http://jan.ucc.nau.edu/~rcb7/370moll.jpg).(1) I want to map this onto a sphere. My results have big black splotches in ...
5
votes
1answer
210 views

MapThread and parallel computing

This time I have a very short question. Is there a deeper reason why ParallelMapThread does not exist? Regards, Frink
9
votes
2answers
300 views

Transition between graphs

I want to visually demonstrate the manipulations made to a graph. For instance, I have a graph g where using the command ...
5
votes
1answer
314 views
4
votes
1answer
437 views

Nonsense Data with Wolfram Alpha + Mathematica?

I am trying to learn how to interface with WolframAlpha. When I try using the Mathematica interface I get nonsensical data. I don't know if this is a bug or if I'm doing it wrong. My goal is to ...
3
votes
2answers
217 views

Showing a forest with root of the trees on the top

I have a Graph object that contains a forest with directed trees. I want to draw the forest such that the root of the trees are on the top and the leaves are on the bottom. If I use the following line ...
157
votes
2answers
37k views

Help find a bright object on Mars!

In today's news, scientists found a bright object on one of Curiosity's photos (it's near the bottom of the picture below). It's a bit tricky to find - I actually spent quite some time staring at the ...
3
votes
1answer
103 views

Setting the context automatically based on section

Suppose I have a task that keeps things organized using contexts, so: ...
1
vote
1answer
183 views

Defining a user defined function in DynamicModule

How can I define a user defined function within DynamicModule? For example, if h[x_] := x^2 I want to find ...
3
votes
3answers
2k views

Map w/ multiple arguments [duplicate]

Possible Duplicate: How do I use Map for a function with two arguments? If I have a function: F[x_,y_,z_]:=x*y*z and I want to call it with several ...
2
votes
3answers
266 views

Maximum tuple value

Is there a simple way to make a maximum tuple value (similar to python)? For example, in python max([ (1,2), (1,3), (3,1), (4,0) ]) returns ...
5
votes
3answers
3k views

Get polynomial interpolation formula

I'm attempting to get a polynomial interpolation formula out of Mathematica but I am absolutely lost. I stared out using ...
6
votes
4answers
1k views

Determining the RGB values of the default plot color

In Mathematica 7, the default plot color is a purple-like color (although I think it is not Purple). Is it possible to use Mathematica to determine the RGB color ...
1
vote
1answer
770 views

Adjusting the legend colors to match that in MatrixPlot

I am trying to show the legend with a ColorData for a discrete Fourier transform coefficient table. Here's a sample data table: ...
10
votes
4answers
2k views

Plot columns of table if some condition is fulfilled

I have a table with data, for example MT = {{1, 80.3, 1, 4, 68}, {2, 80.5, 1, 5.5, 102}, {3, 80.0, 0, 4.2, 78}, {4, 80.4, 0, 3, 17}, {5, 80.2, 1, 5, 180}}; ...
4
votes
2answers
115 views

Lesser and greater symbols in the axeslabels

I need a plot with $\Gamma^<$ as axeslabel using: AxesLabel -> { $\Gamma^<$} But I get an error. AxesLabel -> { $\Gamma^{a<b}$} works though. I think I've to tell mathematica that ...
14
votes
1answer
673 views

Executing Maple Code Inside Mathematica

Is it possible to create a C++ program using MathLink that will invoke the Maple kernel and execute a very basic Maple command using OpenMaple? I'm envisioning the following: ...
0
votes
2answers
255 views

How to get the associated popup menu?

I have threePopupMenu and they work in such a way that second PopupMenu value depends on the value selected by the first ...
13
votes
1answer
359 views

Using Evaluate and Evaluated -> True in Plot

A few use cases: (1) This, as expected, returns (almost) immediately: f[x_?NumericQ] := Evaluate[(Pause[1]; x)] Plot[f[x], {x, 0, 1}] (2) This takes ...
4
votes
2answers
105 views

Factor out invariant code from Plot

Given a simple Gaussian kernel UnscaledKernel[a_, b_, sigma_] := Exp[-(((a - b)/sigma).((a - b)/sigma))/2] and un-normalized smoothing function ...
9
votes
1answer
250 views

How can I change the style of every newly opened notebook?

I'd like to make Mathematica open a new notebook using the Natural Color template (under the Creative category) by default. Is that possible? If so, how?
12
votes
3answers
2k views

Data interpolation and ListContourPlot

I am fairly new to Mathematica and I have two quick questions on using it for a Hydrology and Hydrogeology class. One is about data interpolation and interpolating without any data defined in an area. ...
1
vote
1answer
372 views

Export to Excel gives error for large lists

This is my data mwedata.dat I do this: ...
13
votes
1answer
975 views

Poisson solver using Mathematica

I am looking for some help with a Poisson solver I am writing in Mathematica. The code is quite long with Arrays plugged in, so the full details can be found at http://pastebin.com/uSrSDcW6 I am ...
19
votes
5answers
1k views

Will Mathematica install and run on Raspberry Pi computer?

My club is considering buying a Raspberry Pi computer for tinkering. Can Mathematica be installed on and ran from it?
8
votes
1answer
1k views
3
votes
1answer
355 views

Plotting multivalued function using ParametricPlot

I'm having a bit of trouble making a ParametricPlot from two curves. I defined two functions p and g as: ...
0
votes
2answers
212 views

WolframAlpha queries unevaluated despite internet connectivity?

WolframAlpha is a built-in symbol in MMA8, yet expressions with WolframAlpha and the equal sign operator remains unevaluated ...
8
votes
1answer
596 views

1D Euler Equations

Is it possible to accurately solve the 1D Euler equations in Mathematica using NDSolve? For example, let us consider the problem given here: http://www.csun.edu/~jb715473/examples/euler1d.htm Using ...
15
votes
2answers
368 views

Scaling edge thicknesses

UPDATE There may be some confusion as to the specification of the problem. kguler's answer doesn't really answer the question. I'll try to elaborate a bit at the bottom of the post. One problem ...
11
votes
3answers
508 views

Simpler way to fill date gaps with zero values

One basic problem when working with data like sales and dates is the case where you dont't have sales in all days, so you have to fill it to take information as average or to make a plot. See this toy ...
4
votes
4answers
373 views

Implementing a LineStyleFunction for line plots

I have data in the form: {{0, 3, 4}, {1, 3, -1}, {2, 4, -1}, ...} and I would like to implement something similar to ColorFunction for the style of a line. ...
6
votes
2answers
1k views

Eigenvalue / Eigenvector Calculation

I'm currently trying to compute the three smallest eigenvectors for a 34 by 34 matrix. While I was expecting this to take some time, Mathematica has been running for the past 3 hours, which seems ...
24
votes
3answers
3k views

How to find circular objects in an image?

How could I use morphological processing to find circular objects in an image? More specifically, I need to detect road signs. I need to get the "80 speed limit" sign from this image:
5
votes
1answer
453 views

Unexpected results from NDSolve

I am trying to solve a stiff reaction diffusion system with NDSolve. However, it does not produce the expected results. My problem is a spherical cell with 5 ...
10
votes
2answers
435 views

MovingAverage[] and Fit[] with data containing DateLists

I have data which has the following appearance: data = {{DateList, Real}, ..., {DateList, Real}} It's easy to visualize the data by using ...
2
votes
0answers
252 views

How to plot function & integral with vector variable? [closed]

I want to plot functions & integrals with vector variable the present in this paper. For example the equation (5) at p. 3: I want to plot a chart like figure 5, i.e. the $x$-axis is the angle ...
9
votes
1answer
185 views

Forcing efficient numerical arrays

I encounter strange behaviour of Mathematica when evaluating multi-dimensional arrays of double-precision data. Mathematica can express large arrays of machine-precision numbers using a specialized ...
9
votes
3answers
362 views

Why is AstronomicalData so slow?

I'm having trouble getting some pretty simple functions using AstronomicalData to perform at anywhere near the speed I need them to. For example, I have many ...
10
votes
7answers
743 views

How do I get rid of a “jump” in my plot?

How can I prevent plotting functions from "connecting" inside a plot points that should "wrap around" outside the plot? For example, how do I eliminate the horizontal lines running across the ...
1
vote
1answer
268 views

Asymptotic Rate of Growth

How can I calculate the Asymptotic Rate of growth of a function, for instance like: $X^3 - X^2 - X -1$ EDIT: For instance, as you can see in this graph, after the 1200 the function approximates to ...
5
votes
2answers
244 views

saving Manipulate data inside a notebook

I want to send a few Manipulate Plots and regular plots to my advisor in a notebook. I ...

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