# All Questions

31 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 ...
62 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): ...
25 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 ...
21 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 ...
20 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 ...
46 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]}] ...
38 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, ...
37 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 ...
36 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 ...
39 views

### Integration not working, can I find a closed form?

I have tried: ...
33 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 ...
195 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 ...
61 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 ...
35 views

### Faster way to build a specific height in a thickness plane graph?

Test image can be a Plot, ParametricPlot, RegionPlot, ...
17 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 ...
56 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. ...
38 views

### Histogram from a list of matrices

I have a list of around 100 matrices, that looks like this ...
124 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. ...
20 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 ...
55 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: ...
41 views

### Open Mathematica in text editor displaying just the code

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 ...
49 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 ...
31 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. ...
414 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 ...
50 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: ...
30 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 ...