All Questions

28 views

Simple pattern/texture on chart elements

If I print the following BarChart in black and white, then it is very difficult to tell which bar is "a" and which is "b". ...
27 views

Nested Recursion Equation

I have been trying to solve a system of recursive equations using Mathematica. However, when I do something like this: ...
6 views

package file shows blank in editor

I copied a .m package file that I wrote on a Windows machine to my Mac running Mathematica 10 in OSX 10.9. I can see the contents in a text editor and I can load it into a notebook and the functions ...
24 views

Manipulate causing frequent crashes

I am putting together a dynamic 3D plot which is to be "manipulated". The code does what I want it to, but keeps crashing all the time. Sometimes it crashes the kernel, so I just have to run the ...
32 views

Numerically integrate and find roots [on hold]

I want to perform the following operation 1- f(k)= integral(r+k,{r,0,pi}) 2- roots(f,k) i.e. first integrate the function w.r.t "r" and get symbolic expression in terms of k. Then find the roots of ...
15 views

How to export quicktime video as h.264?

I am trying to export sequences of images as quicktime movies. The dafault codec (cinepak) produces low quality and large file sizes. There is little documentation of the other codecs, which can be ...
36 views

Eigensystem on HPC

I am submitting Mathematica jobs to an HPC. I have a large matrix that is a function of (x,y) and I am diagonalizing it for around 500 points in the plane. My initial idea was to request a node with ...
34 views

Modifying a list of matrices with conditional statement

I have a list of around 100 matrices, that looks like this ...
34 views

Non linear Model Fit error

I am a chemistry student, and I am trying to fit a isotherm for physicalchemistry, for some reason I cannot do it... This is what I've done: data = {{0.617, 0.8}, {0.605, 0.6}, {0.5997, 0.4}, ...
15 views

How to keep computing Hilbert transforms until I find the right one

I would like to get mathematica to arbitrarily plug in pairs of functions to the Hilbert transform operation, and to stop as soon as it gives me a pair of Hilbert transforms that obey certain ...
19 views

How to invoke default VertexShapeFunction and EdgeShapeFunction from custom ones?

For this question, g is a Graph object (of order ~2K) such that the VertexWeight and ...
33 views

Importing file as a string causes a puzzle

I generate simple txt file and import it as follows: a = Import["binary.txt"]; b = Import["binary.txt", "String"]. It appears then that lengths of imported strings ...
47 views

Poisson PDE using FDM in Mathematica

The problem modeled by the Poisson PDE is related to the torsion of prismatic beams and I use the Finite Differences Method. When I use Mathematica to solve it using a quadratic mesh it is working ...
49 views

Expand just first level of an expression

Is there a way to build a function to expand just the first level of powers and products of an expression? Edit: ...
75 views

Visualisation of intrinsic curvature

I know that Mathematica allows for a lot of nice visualisations, so here I am. I was thinking if one could visualise (using Mathematica) the fact that a 3d (or simpler a 2d one) Torus doesn't have ...
103 views

Why does the documentation call functions “pure”?

Clearly, functions in mathematica are not pure functions according to the definition on Wikipedia (no side effects - basically implementabe with table lookups): ...
37 views

Simulating Dynamic Priority Queues

I have found several examples of static priority queue implementations: there are two classes of items, with the exponential interarrival times. The service times are also exponential. The first-class ...
30 views

Confusion/Problem with importing Packages in Mathematica

I am very new to Mathematica and managed to confuse myself completely while trying to import a package. I am supposed to use a package that I did not code myself (it definitely works though). I ...
32 views

Does mathematica have “Realized Covariance” function?

Does mathematica have "Realized Covariance" function? I see that the function called "CovarianceFunction" may be a little close to this, but it is not so easy to see the actual "realized" property ...
55 views

Concise way to express Table[FactorInteger[300][[n, 2]], {n, 1, Length @ FactorInteger[300]}]

I can get the exponent part of FactorInteger[300] with Table[FactorInteger[300][[n, 2]], {n, 1, Length @ FactorInteger[300]}] ...
49 views

Mathematica integration error

Integrate[Integrate[Abs[Exp[2*Pi*I*x] + Exp[2*Pi*I*y]], {x, 0, 1}], {y, 0, 1}] yields 0 as result. This cannot be correct, ...
46 views

Removing non-word characters in certain parts of a string

I would like to ask how I can remove non-word characters from a string, but only in certain cases. I have read this article, so I know how to get the words out of a string. My text is however a bit ...
44 views

Exporting animated gifs; “AnimationRepetitions”->1 doesn't work

I'm trying to export a table of graphics into a gif animated file with just one repetition. Export["C:\Race.gif", t, "AnimationRepetitions" -> 1] It doesn't ...
48 views

Integration not working, can I find a closed form?

I have tried: ...
47 views

How could I upload a XLS file to Cloud and then plot it?

I want to upload a file to the Wolfram Cloud and plot the list: So I use the following code to check its head at the beginning: ...
10 views

formulate a condition that function f(x,y) must hold in order to be considered as “associative” [migrated]

Let f(x,y):{0,1}^2->{0,1} be a Boolean function. Answer the following "warm-up" questions: a. Prove or dispute: The function f can be one-to-one. b. Formulate a condition that function f(x,y) must ...
305 views

Computing a map between two lists

What I want is a little difficult to explain. So I try to it with an example. I have 2 lists, each of which has $(n-1)^2$ elements. Each element is an integers between 0 and $n-1$, inclusive. For ...
72 views

Finding the point of best focus for a ball lens

This is my project (simulation): A set of parallel rays goes trough a ball lens (circular lens). Because of spherical aberration, refracted rays will not meet in a single point. Find the distance ...
36 views

Faster way to build a specific height in a thickness plane graph? [duplicate]

Test image can be a Plot, ParametricPlot, RegionPlot, ...
21 views

Put/Get don't accept a string-valued expression as filename [duplicate]

I'm trying to do the following with an expression: filename=StringJoin[{"myfile", ToString[someNumber],".m"}]; expression >> filename; But mathematica ...
65 views

Curve fitting of a list

I have list obtained using an integrals. I want to obtain an analytical formula that fits my list using curve fitting. Please suggest a simple analytical structure that fits my curve. ...
66 views

Histogram from a list of matrices

I have a list of around 100 matrices, that looks like this ...
134 views

Grid lines extending too far

The grid lines in the following plot extend beyond the data and, in particular, into the numbers along the axis. ...
23 views

How to automatically Import, Name and Export multiple images? [duplicate]

Sorry for the very basic question but I'm really new to Mathematica. I have a directory(myDataDir) full of images (myImage1.tif, myImage2.tif...) I have a piece of code (let's call it ...
58 views

Wrong Definite Integral result [on hold]

When I calculate the definite integrate of (a+bt)*cos(nt). Integrate[(a + b t) Cos[n t], {t, t1, t2}] MMA gives a correct answer: ...
42 views

Open Mathematica in text editor displaying just the code [on hold]

I need to translate some code to another language and I don't have a working copy of mathematica. All I need it to do is display the code exactly as it would in mathematica, without any of the fancy ...
53 views

Using RegionPlot3D to make a cone under restrictions

I have to plot a cone that satisfies this statement: Use the RegionPlot3D command to draw a picture of a cone with its point at the origin. The other end of the cone is a circle with radius 5 ...
32 views

Using real numbers gives suspicious result

In the code below when I use a real number for number 4 in the exponent in the irf function, it returns wrong result. ...
561 views

How to wrap a plot around a circle?

Consider the code a = Table[BesselJ[i, x], {i, 0, 3}] Plot[a, {x, 0, 20}, Axes -> False] producing I'd like to transform the plot into a circle. In other ...
31 views

How to replace colours in an image from Wolfram Alpha [on hold]

I recently saw this post on the Wolfram Blog. I have tried doing the exact same thing on the blog but I'm not getting the same results. I'm getting this image: Instead of this: I'm also ...
55 views

Proof that $(1+\epsilon)^n = O(1+n\epsilon)$ [on hold]

How to prove that $(1+\epsilon)^n = O(1+n\epsilon)$ ? So far I proved the following: By the binomial, $(1+\epsilon)^n > n\epsilon$ Also $\epsilon^n$ = 0 when n-> infinity.
60 views

Problem in Plot at start [duplicate]

The derivative can be used to calculate roots. However the same function cannot be plotted.The error is at start point of domain: ...
32 views

Mapping also for one element (or telling it how to do so if head got changed)

Some code generates a polynomial, and has the form: expr = Plus[a[i],b[i],c[i],d[i]] I need to apply f to each term. To do ...