-1
votes
1answer
130 views

How can I check which file is modified in specific directory?

I want to find which files are recently modified in a specific directory. For this purpose, I wrote a function named Test. The function's argument is ...
2
votes
1answer
257 views

Extracting information from list

I have a huge list that looks like this: ...
6
votes
3answers
500 views

Counting the number of a specific type of permutation

In the theory of cumulants of vector-valued random variables, the following types of formulas appear: \begin{equation} \theta^i \theta^{jk} [3] = \theta^i \theta^{jk} + \theta^j \theta^{ik} + \theta^k ...
3
votes
1answer
222 views

Issue with ListConvolve

I am a new Mathematica user, learning the intricacies of functional programming. I have issues withe applying a function over a moving list. My function seems to work and give correct results but it ...
0
votes
1answer
588 views

Evaluating FindRoot at different starting points on a grid

I'm trying to evaluate the roots of a complex function at different starting points on a grid using Do[Do[FindRoot[g[z], {z, j + k*I}], {j, 10}], {k, 10}]. However, ...
5
votes
4answers
505 views

How to transform Do loop to more efficient codes?

I'm new to Mathematica. Here is my original program: How to rewrite the Do part? ...
5
votes
1answer
340 views

Which DirichletCharacter is KroneckerSymbol?

If $d$ is a fundamental discriminant, KroneckerSymbol[d,n] is a Dirichlet character modulo $|d|$. Which one is it? If $d>0$ is a prime $\equiv 1\bmod 4$, then ...
2
votes
1answer
145 views

Detect Standalone CDF vs Browser Plugin environment [duplicate]

Recently, Wolfram informed me that there's no way to have a Print button in a CDF running within a plugin environment since the plugin does not interact with the operating system. If you have a way to ...
35
votes
5answers
3k views

Distribution of random points in 3D space to simulate the Crab Nebula

I'm generating some 3D models of planetary nebulae and supernova remnants for Celestia, a free OpenGL astronomy software. Currently, I know how to do it with random points inside a spherical shell. ...
13
votes
5answers
2k views

How stretch curly brace on multi-line text?

What's the cell option (or other technique) to use to stretch the curly brace that one typically uses in traditional math to group several displayed equations? Like this: And is there any better ...
8
votes
1answer
217 views

How can I add a background to a stylesheet?

In version 9 we can set the background to an image, however I'd like to save this into a stylesheet that can be installed.
2
votes
2answers
189 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 ...
5
votes
2answers
893 views

Is there an $n^{\text{th}}$ root function in Mathematica?

Is there a way to find $\sqrt[n]{x}$ with Mathematica beside of x^(1/n) as this is something different, because this is not always the same $$(-1)^{\frac{2}{4}}=i ...
3
votes
2answers
415 views

Find the a factor of an integer which is nearest to another integer

If I know two integers $n$ and $m$ and $m < n$, how can I find two different integers $x$ and $y$ that are nearest to $m$, and satisfy Mod[n,x]==Mod[n,y]==0 ? ...
8
votes
3answers
330 views

Reduce the output from tuples by including symmetry?

I need all the possible 3x3 binary tensors, but I'd like to have this account for symmetries. I've started by using the Tuples command. Tuples[{1, 0}, {3, 3}] ...
0
votes
1answer
186 views

Interpolating a Bivariate Polynomial over a Finite Field

Let $F=GF(p)$ be a finite field, $p$ prime and write $F^\times=\{x_1,\ldots,x_n\}$. I'm trying to implement an earlier version of Sudan's list-decoding algorithm for Reed Solomon Codes ...
3
votes
3answers
311 views

How to paint part of DateListPlot?

My graph is about fires (burned area) over 12 years presented in one Date List Log Plot. Because most of fires are in summer (as expected) I would like to highlight that with different background ...
6
votes
1answer
147 views

How can I keep a plot's filled area from obstructing other lines when exported as EPS?

I am plotting several functions, some of which have fillings. After I combine all the functions together on a plot and export the plot to an EPS file, the fillings obstruct other lines. Exported PDF ...
3
votes
1answer
1k views

Increasing the size of numbers in a legend bar

I would like to know how you go about increasing the size of numbers which appear in a legend to make them larger than the default (which is too small for publication purposes). Example: ...
1
vote
1answer
149 views

Output Export in Mathematica

I have a command line that generates lists as output and is running in a loop, so generates, multiple long lists. Each list is to be exported as a .txt file. How can I automate the name generation of ...
3
votes
1answer
246 views

Sum of positive terms gives negative answer

Mathematica evaluates Sum[((n - y - 1)*(n - y)^2*n^y)/y!, {y, 0, n - 2}] as -2 e^n n. This should not be a negative value. ...
3
votes
1answer
204 views

EmpiricalDistribution for Gini Coefficient Runs Slow

I am repurposing code that I found in this blog post (http://datavoreconsulting.com/sports/gini-coefficients-and-the-olympic-medal-race/) to generate the Gini coefficient for other data sets I am ...
7
votes
1answer
189 views

Can I set 'no-go' values in a Manipulate slider?

Is it possible to easily modify a Manipulate such that the slider automagically skips certain values? For example, say I am plotting an equation that's perfectly ...
0
votes
1answer
1k views

How to give axes label to a histogram

I plotted a histogram and I used AxesLabel for labeling X axis and Y axis But it went wrong. How to do it?. ...
4
votes
2answers
318 views

Is it possible to export a live CDF document to PDF in the browser?

I am creating a computable document format (CDF) to embed in an HTML page. I would like to have a button that can be clicked to create/save a PDF of the CDF fromt he browser. The idea is that a person ...
3
votes
1answer
527 views

How to get the determinant and inverse of a large sparse symmetric matrix?

For example, the following is a $12\times 12$ symmetric matrix. Det and Inverse take too much time and don't even work on my ...
4
votes
1answer
3k views

Transform 3D data into 2D color map like Matlab's surf/imagesc

I have a bunch of 3D data (x, y coordinates and values) which is generated in Matlab and I need to render them in a 2D color map with certain axis ranges. Here are the Matlab code and the generated ...
22
votes
3answers
394 views

Efficiently appending points to a NearestFunction

I have a program which works with a list of points (in 3D, but it could be in 1D as well, it won't make a difference). Within a loop, it keeps adding new points to the list. To calculate the ...
1
vote
1answer
185 views

Colors not showing in Graphics3D

The following code works, except that the colors aren't showing in the output. Wh? I probably made a trivial mistake, but I'm yet unable to find it. ...
2
votes
1answer
250 views

Integrate[(1 + x/n)^n*Exp[-x], {x, 0, Infinity}]

I evaluated Integrate[(1 + x/n)^n*Exp[-x], {x, 0, Infinity}] . thinking the answer should be approximately $\sqrt{\pi n/2}$. Mathematica gave me ...
0
votes
1answer
334 views

NumericQ prevents evaluation at a numerical value sometimes

I set up a symbolic integral, to be evaluated only when some of the symbols have been replaced by numbers. The evaluation after assigning numbers to the symbols is still symbolic for some reason. The ...
0
votes
2answers
552 views

Cumulative frequency plot

I have the following data: data = {{0, 0}, {20, 1.4}, {25, 9.8}, {30, 32.2}, {35, 38.2}, {40, 15.6}, {45, 2.7}, {50, 0.1}}; where the second coordinates are ...
2
votes
1answer
327 views

How to reject or repulse some points in a 3D cloud of particles?

I'm having an issue with a 3D distribution of points. The distribution is really nicely looking in Mathematica, but it is used in an OpenGL astronomy program (Celestia) to generate a nebula, with ...
-1
votes
1answer
119 views

FindFit and Integration errors

First off, appologies for what may sound like a newbie question, as I am very new to using Mathematica. I am trying to find a way to get Mathematica to give me an expression that would describe the ...
4
votes
1answer
150 views

Identical code, different answers?

I'm having some trouble with identical code giving different answers. On a fresh kernel (MM 9.0.0.0, Windows 64-bit), running the same code, copy-paste, gives two different answers: ...
1
vote
2answers
222 views

Subtract more than one array using DeleteCases

I need to create an array subtracting two arrays from another array. I know how to subtract one: am = DeleteCases[amp, Alternatives @@ af] I can subtract an ...
4
votes
1answer
335 views

Remove the white margins of a Graphics3D figure

If the option Boxed is set to be False in Graphics3D, additional white margins may appear as ...
6
votes
2answers
380 views

Find all permutations with a condition

How can I find all the permutations of {a, b, c} where a + b + c = n? For instance: if ...
3
votes
1answer
629 views

Are there any openCL test suites?

I have a new ATI gpu that I have been trying on 3 different distributed computing projects. I get errors on each work unit. The errors indicate No Protocol which could be caused by a bad environment ...
3
votes
1answer
239 views

Integer partitions in all orderings

I want to partition an integer into $k$ integers all possible orderings. This can be done in the following way ...
0
votes
1answer
317 views

Why won't ContourPlot accept a variable argument? [duplicate]

I have a list of linear inequalities which describe a (polygonal) region. I can use RegionPlot to visualize this region; but I'd also like to overlay this plot with ...
5
votes
2answers
364 views

Keep Ordering of Bra Ket When Printing

I would like to keep the ordering of the bra ket-print but right now this doesn't happen. Any Idea? I tried playing with HoldForm but then i could evaluate the expression inside properly ...
1
vote
2answers
443 views

Select rows from table by keys

I am looking for a way to iteratively select all sublists with the same ID (my 1st column, residual columns are AbsoluteTime entries). First, I obtained the list of ...
4
votes
2answers
717 views

Transparent Cylinder with Dashed Edges only

I would like to have that kind of cylinder with Dashed edges (including the bellow inner ring): I've been trying that: ...
2
votes
1answer
63 views

Avoiding re-evaluation of RegionPlot3D on a second computer

After running a RegionPlot3D named "testplot" on my desktop, I followed an earlier suggestion from the forum and saved it using: ...
4
votes
1answer
457 views

How to show error messages in current notebook?

I would like Mathematica to print error messages in current notebook together with output. This is default option in Mathematica, but recently I turned it off somehow. Now, I am getting output in ...
4
votes
2answers
678 views

What can I do to eliminate the error FindFit::nrjnum:?

I am testing the "Power Law with finite-time singularity" hypothesis for world population growth for a project. The data I'm using (same behaviour should also be exhibited by the stock market, thats ...
4
votes
1answer
187 views

Plot3D list elements

I've been having some trouble with Plot3D. I have a quite complex function of two variables (actually three but the first one doesn't matter) that returns a list ...

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