2
votes
1answer
391 views

Volterra integral equation : 'literally match the independent variables' message

I want to solve an Volterra type Integral equation, and as a practice I entered the following code to my mathematica: ...
12
votes
3answers
358 views

How to memoize a function with Options?

Consider the following modified fibonacci function: ...
3
votes
1answer
337 views

BarChart and Log Scale results in different bar origins

I want to create a bar chart from two different data sets. ...
5
votes
3answers
664 views

Using PlotLegends

Please don't answer this with "Just trash PlotLegends" or anything like that as I have tried homebrew solutions. I keep running into problems which I can't debug as ...
0
votes
1answer
536 views

integration on real domain only!

i am trying to integrate a real valued function. For some reason, Mathematica gives an answer in the complex domain. I'd be grateful for your answers. Here is the integral: ...
27
votes
5answers
2k views

How to efficiently find positions of duplicates?

Is there an efficient way to find the positions of the duplicates in a list? I would like the positions grouped according to duplicated elements. For instance, given ...
3
votes
3answers
165 views

Dynamic application of several polynomials

I know how to get the 'resulting image' (y) from the application of a certain function (f) (here represented as the coefficients of a polynomial) over a certain interval (x): ...
0
votes
1answer
296 views

How to define a fixed length vector in Mathematica?

I would like to define a 3-D vector as say v={x,y,z}, but I want it to have a fixed norm, say a unit norm |v|=1. How do I impose this condition on v.
0
votes
1answer
149 views

High quantum harmonic eigenfunctions?

How to obtain high quantum harmonic eigenfunctions? Everything works until, let say 65th eigenfunction, but for higher eigenfunctions values are too high. My code ...
1
vote
1answer
129 views

Unwanted hold in recursive function

I have a function (let it be called f) that does something useful for me and I want to be able to apply it to the elements of a list regardless of their depth and keep the list structure. For example ...
-4
votes
2answers
177 views

how can i convert data into string format? [duplicate]

I have nested-lists in number format,like data={{1,2,3},{2,{3,4,50}},{4,5,6},{3,{3,{5,6}}}} I want to convert each number into ...
3
votes
1answer
143 views

How to change texture of chart bar?

Is there anyone who know how to make diagonal lines inside the chart bar like the below picture?
2
votes
1answer
227 views

How can I prevent these warnings while using ParallelTable

I have this code to find all the permutations of a set of letters that form legal words. ...
5
votes
1answer
426 views

How do I put an image on the complex plane?

I watched this video and became interested in transforming an image. But I have no good idea on how to embed an image in the complex plane using Mathematica. I have a method that seems to work, but ...
3
votes
2answers
477 views

For loop with steps other than 1

I would like to do a For loop with a jump 2*Pi instead of 1. For[j = 0, j <= nmax, (incr = 2 Pi), ...] Actually what I want to do is ...
0
votes
3answers
218 views

How to evaluate all the essentially distinct polynomials in 4 variables over $F_2$ on points of $F_2 ^ 4$

I am a beginner with Mathematica. For my research purpose I would like to get a list of all the polynomials in $F_2[x,y,z,w]$ and for each polynomial I would like to know the result that it gives then ...
7
votes
1answer
452 views

How can I get Mathematica to recognize the documentation for a newly installed package?

To install a new package on one's machine, one first downloads and unpacks the package into the $BaseDirectory/Applications directory. The tutorial Installing ...
0
votes
1answer
78 views

Error with minimization of NProbability

I'm trying to solve the following problem: ...
7
votes
1answer
501 views

Mathematica memory management for large arrays

I have come across a weird phenomenon in Mathematica when dealing with large arrays. When generating a list with all the possible subsets of three elements of another list (thus having elements which ...
1
vote
0answers
349 views

Testing the convergence when solving an integral equation

I am trying to find the solution of an integral equation such that a certain convergence criterion is fulfilled. Now the problem is that the function doesn't look like what I am actually expecting, ...
2
votes
1answer
187 views

Transfer of symbols between contexts

As many others (I guess) I'm struggling with the handling of contexts within Mathematica. I'm working on a new package definition with the usual syntaxt specified by the Mathematica documentation: ...
1
vote
2answers
255 views

Running out of memory when filtering a large data set

My goal is to read list0.dat, filter the data with a function f, and then write the transformed data to ...
0
votes
1answer
284 views

Why is EigenValues returning Root expressions?

This is the code I have: ...
2
votes
1answer
434 views

Problem using the DifferentialEvolution method of NMinimize [closed]

I have a function of 20 parameters, which 3 of the parameters are my physical parameters, and the others are pull terms to fix the errors. The goal is finding the global minimum of this function, to ...
11
votes
3answers
938 views

What is Mathematica's equivalent to MATLAB's filter function?

The MATLAB code filter(0.5,[1, -0.5], [1:10]) is equivalent to Rest@FoldList[(#1 + #2)/2. &, 0, Range[10]] I don't ...
2
votes
1answer
139 views

Replace a specified portion of an array with elements from another smaller array

This may be a trivial question, but I have been at it for a couple of hours and I have not made much progress. I have a 10 x 10 array (T) that I have used to generate an 8 x 8 array (Q). I want to ...
6
votes
3answers
366 views

AxesLabel in Histogram3D unreadable

I'd like to modify this chart to relocate the z axis label so it's not over printing the values. ...
8
votes
2answers
146 views

Possible to scope an anonymous function within Module?

This is my first question. I'm fairly new to Mathematica and completely new to SE, so I apologize if this question is trivial. I'm working on a problem that requires a function to be redefined ...
12
votes
2answers
417 views

Need help coding/creating a recursive list

I have two lists A and B, each with 99 real numbers. I want to form a list, C, whose ...
2
votes
3answers
209 views

Defining a function to determine when convergence is guaranteed

I'm investigating how many iterations are needed for a particular orbit to reach a fixed point of a function. Since I have many functions to test, I want to define a function in Mathematica that will ...
0
votes
1answer
89 views

Why does Eigenvalues[matrix I defined] not work? [duplicate]

This is the code I have in my mathematica notebook. I want to find the eigenvalues of the matrix I created called Hmatrix as defined below. However when I type Eigenvalues[Hmatrix] I get the Hmatrix ...
4
votes
3answers
325 views

Color function doesn't span the whole color range in MatrixPlot

In matrix visualization, for instance, MatrixPlot[{{1, 2}, {3, 4}}, PlotRangePadding -> 0, ColorFunction -> "Rainbow"] the color map does not cover the ...
1
vote
2answers
548 views

Weird NDSolve behavior with Piecewise (MMA9)

NDSolve in Mathematica 9.0.0 (MacOS) is behaving strangely with a piecewise right hand side. The following code (a simplified version of my real problem): ...
2
votes
1answer
156 views

Mathematica Presentation Cell Formatting

In one of the Mathematica (v9) slide templates, they have an example cell that looks like this: Where there is a "SideCaption" that appears to be the Mathematica-equivalent of a text box to the ...
1
vote
1answer
560 views

How to calculate a gradient at x=0?

I am solving a second order differential equation for n[x]. I solved it with both DSolve and NDSolve. A plot of n as a function of x looks great. Than I want to calculate a gradient of n[x] at a ...
7
votes
4answers
588 views

Extracting variables from an expression

I'm looking for a way to extract a list of variables from an expression, for example with an input like: ...
3
votes
2answers
225 views

In a Manipulate[], control timing of Autorun

I've made a gauge like instrument that will get used to prompt someone to maintain rhythmic breathing patterns during heart/brain coherence training. ...
1
vote
1answer
147 views

Need assistance with plotting Cell Center Points and Normals (ListPlot, ListVectorPlot)

This is the CellCenter datapoints and associated Normals data: http://wikisend.com/download/458974/CellCenters-and-Normals.dat The dat file contains data points for x,y coordinates and x,y ...
4
votes
1answer
132 views

Closed form for convolutions of random variables

Is it possible to get Mathematica (9) to calculate PDF's for combined distributions? I can't seem to find the right notation, if this is possible at all. My attempts: ...
30
votes
2answers
1k views

Generating “Penrose-style” drawings of surfaces

In The Road to Reality there are plots of surfaces that use a variable density of dots to suggest curvature. You can see some examples here and here. I suppose they've been drawn by Penrose, but ...
1
vote
1answer
315 views

Gauss Markov Process

I am trying to model a 1st order Gauss Markov Process (gyroscope drift). I know the Allan Variance characteristics of the process (bias instability, random walk characteristics). I know the model ...
4
votes
1answer
260 views

How to force Pane to always scroll to end of content? [duplicate]

Mathematica seems to know about the actual end of content position in a Pane if given large enough (but not too large$^1$) initial position value. Here, the ...
5
votes
3answers
906 views

Remote Mathkernel: SSH encountered a networking error while launching kernel Error code = 1

I have a problem concerning the connection to a remote kernel via ssh on a vpn. I found a working configuration in this question: Connection to remote kernel can not be established - No specific ...
1
vote
3answers
2k views

How can I use assumptions with FindRoot?

I have something like FindRoot[f[x], {x, a}] Now I want FindRoot to constrain the solutions to 0 < x < 1. How can I ...
15
votes
3answers
2k views

Making Axes logarithmic in 3d plots

I've been trying to get loglog plots in 3D, but to no avail. My initial approach was to take the logarithm inside the plot i.e ...
1
vote
1answer
236 views

Troubleshooting an NDSolve::ndfdmc error message

Τhe following code ...
1
vote
1answer
137 views

Using only two colors in a ListPlot3D

The data I have given here will plot the data in ListPlot3D function and gives the visualization of bars on the plot. I want to customize the color for the bars in ...
-1
votes
3answers
203 views

MixtureDistribution in Mathematica 7

Is it possible to use a mixture of several distributions in Mathematica 7.0? Consider for example the following code : ...
2
votes
1answer
195 views

Extracting information from list

I have a huge list that looks like this: ...
-2
votes
1answer
117 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 ...

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