5
votes
0answers
57 views

Creating a certain image (3D shadows, highlighted intersections)

I would like to learn how to code within Mathematica the following picture: I tried using ...
0
votes
1answer
77 views

How to let Mathematica ignore complex values in Plot functions?

Consider the polar coordinates function of a circle centered at $(2,0)$ with a radius of $\sqrt 2$: $$\rho(\theta)=\left\{\quad \begin{array}{c} 2 \cos \theta +\sqrt{2-4 \sin ^2\theta} \\ 2 \cos ...
3
votes
1answer
211 views

Multivariate resultant in Mathematica?

Is there any command in Mathematica 7 which can compute the (McCaulay) resultant of a parametric system of multivariate polynomial equations? In fact, it would be great if there is also a way to ...
0
votes
0answers
86 views

Numeric error in trivial compilation

I came across this strange problem: dd = Compile[{}, Abs[(10^-200 + 10^-200 I)/(10^-200 + I 10^-200)]^2, CompilationTarget -> "C"] dd[] ...
0
votes
1answer
105 views

How to make the plot smooth

There are some stranges point which cause the figure isn't smooth. I think that the reason is the method of numericial integration. Here is my code, it's pleasure that one can revise the drawbacks in ...
2
votes
1answer
71 views

Multiple colors on a single graph edge?

Is there any way to put two colors on one single graph edge? For example, I want to highlight two cyclic paths (red and blue). But, if I put the two colorings into one image, it does not work as I ...
3
votes
2answers
93 views

Convert DateObject into TimeObject

How to elegantly convert from DateObject to TimeObject? The purpose is to extract time from the DateObject and manipulate only ...
8
votes
3answers
328 views

Select Cells to End of Notebook

I'd like to create a keyboard shortcut that will allow me to select all of the cells from the current cell until the end of the notebook, similar to how ShiftCtrlEnd functions when editing text in ...
5
votes
0answers
56 views

Can Predict/Classify be parallelized?

Being able to parallelize Predict /Classify would be useful on multiple fronts: Performance/Scale Streaming Pedagogical ...
6
votes
2answers
240 views

Modifying the elements of a list according to a given probability

Let list be a list of lists, the elements of which are random integers in the interval $[1,c]$. Each element $i$ has a probability ...
21
votes
2answers
162 views

How can I evaluate untrusted Mathematica code in a sandbox?

Is there any way to build a sandbox to evaluate untrusted Mathematica expressions in order to prevent them from having (malicious or accidental) harmful side effects? Context: I'm developing a system ...
6
votes
5answers
161 views

Nested list from a flat folder list

I have a list of folders and files in my current working directory as a result of a built-in function FileNames: FileNames["*", "", Infinity]]. It looks like this: ...
0
votes
0answers
46 views

Large lists to manipulate later in chunks [on hold]

If I try to evaluate either one of the following expressions: Table[n, {10^8, 10^9] Range[10^8, 10^9] I get ...
34
votes
5answers
9k views

How to use Mathematica functions in Python programs?

I'd like to know how can I call Mathematica functions from Python. I appreciate a example, for example, using the Mathematica function Prime. I had search about MathLink but how to use it in Python ...
0
votes
1answer
42 views

Solving recursions

This question is tied to my previous question. I have a few recursion formulas, and I keep getting Recursion depth of 1024 exceeded. error. I need to get the ...
0
votes
1answer
30 views

Calculate Max-Min value and corresponding parameters

I have two functions funA and funB which are also functions a,b,x,and ...
0
votes
0answers
50 views

Piecewise NDSolveValue: Nested Variable Iteration

I am attempting to make the variable Rc a piecewise-function of [z] and have it update as NDsolve iterates through the range of 'z' such as {z,0,Le), but to no avail. The following code is an attempt ...
8
votes
1answer
356 views

“Choose how to enter input” - leave me alone

How do I get rid of this: I can't find the appropriate entry in Option Inspector or in WolframPredictiveInterface.
15
votes
3answers
1k views

Can Mathematica's random number generation be improved?

Performance on Random Number generation is intolerable. Whenever you need many deviates from the same distribution but with different parameters it takes forever. Here is a thread on Poisson ...
1
vote
1answer
52 views

Fraction shortcut not working, giving strange spacing character on german keyboard

So usually when you want to enter a fraction in Mathematica, you can do so by pressing "Ctrl+/". If you are on laptop with a german keyboard however, you will have to press "Ctrl+Shift+/" since you ...
3
votes
0answers
40 views

How to export to NetCDF format

Consider I have a scalar field on a grid f(x,y), where x and y can take values ...
10
votes
1answer
54 views

How to speed up the evaluation of a function with a large LeafCount but many repeated sub-functions for use in NIntegrate

General Context Apparently, the memory leak in NIntegrate is unavoidable pre-MMA-10.2. I have some (two-dimensional) numerical integration to do on a complicated ...
4
votes
1answer
138 views

How to show the projections of 3D orbit on the three primary planes

Perhaps this question has been asked before but even though I searched the site I did not find what I want. The code is rather simple: ...
1
vote
1answer
147 views

Printing problem in our campus lab

We have 12 iMacs in our computer lab at our college. Our students are having problems trying to print (to a black and white printer) their notebooks. Testing one students notebook (about 6 pages with ...
-2
votes
0answers
39 views

Define function of two variable like a vector [on hold]

I have very repetitive exercises to do and I need to control very fast the result. In order to do this, I need to define some different functions ... First of all, I need to define this ...
6
votes
1answer
50 views

ImageAdjust Documentation issues

A recent thread raised several concerns regarding the Documentation page for ImageAdjust. The first issue is related to the first statement under the ...
0
votes
1answer
332 views

Finding resolution of an optical system using Rayleigh criterion

I want to use the Rayleigh criterion to find the resolution of an optical system. I have two functions f1 = Sinc[x]^2 and ...
14
votes
2answers
469 views

How to detect loops in a vector field?

Given a vector field and I'd like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this: ...
3
votes
1answer
85 views

Range of summation in simple Plot seems off

I was trying to reproduce a picture in a book by Havil of the sum, $$s = \sum_{r=1}^{\infty}\frac{\mu(r)}{r}\left(Li(x^{\rho_k/r})+Li(x^{\rho_k*/r})\right) $$ using ...
1
vote
0answers
50 views

Is there a hidden location-type property for TropicalStormData?

TropicalStormData gives you time-series data on tropical storms. In the property list there is not a location (geographic coordinates) property listed. There are ...
7
votes
1answer
70 views

Reading NIfTI-1 files

How can I read NIfTI-1 files (.nii extension) in Mathematica? Are there existing tools for this?
2
votes
2answers
71 views

Perform calculation on several sublists using Map

I am trying to perform a calculation on a list containing sublists. More exact: The x-axis values are time data, progressing from zero, the y-axis data are data points, which I want to normalize. I ...
0
votes
1answer
44 views

Invoking WorkingPrecision slows down Eigenvalue calculation drastically?

Normally, obtaining eigenvalues of random numerical matrices is fast. For instance a generic result looks like ...
0
votes
1answer
54 views

Applying transformations to data coming from an STL file

I am very new with the use of 3D graphics in Mathematica, so my question might be very naive. I need to Import an STL file, apply transformations to it (rotation and translation), and export it back ...
0
votes
0answers
17 views

Require Formula to work out size of Share Units with given variables [on hold]

Formula required to find out size of Units at Break even point given various variables. The variables A, B, C are the differences between 3 separate Levels in price and a new common take profit level ...
0
votes
1answer
43 views

Changing notations for probability moments with subscripts

Suppose I have have two kinds of variables $X_{\alpha_j}, X_{\beta_k}$ in the form of Subscript[x,Subscript[α,j]] and ...
2
votes
2answers
82 views

Building a sequence of the digits of π

Just for fun, I'm trying to write up some code that will list a finite number of the digits of pi, i.e. {3,1,4,1,5,...,#}. I have the general pattern, but for some ...
1
vote
0answers
44 views

Typesetting a formula

I want to input a formula like the one below: but occasionally when I use classroom assistant in Palettes the formula I am still typing will become something ...
2
votes
0answers
51 views

Detecting discontinuities in derivatives in images

Considering an grey-scale image as a function $z=f(x,y)$. (Specifically, I'm interested in $f=h*h*...*h$, where $h$ is the indicator function of a regular hexagon.) I am interested in finding places ...
4
votes
4answers
192 views

Finding relevant parts in XML document

My question is about a XML document and finding parts of strings. test = Import["C:\\Users\\filename.xml", "XMLObject"] This gives the following output: ...
4
votes
0answers
89 views
265
votes
25answers
35k views

What are the most common pitfalls awaiting new users?

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
2
votes
4answers
196 views

How can I make a summary of all the commands of Mathematica?

I would like to have a simple way to get summary information about all the many commands built into Mathematica. How could I do this? Is there a site I may refer to?
0
votes
0answers
48 views

memory aid frequently used commands [on hold]

I am looking for links to a summarized list of most used commands of Mathematica or a reference manual with examples that only includes commands and syntax. I would also like a list of keyboard ...
1
vote
1answer
50 views

Module inside module in `Compile`

How can I make compilation to go through with a module inside module? I tried this, failed, a few other ways failed too. ...
1
vote
0answers
31 views

Equilateral triangulation of a polyfile-defined surface

I would like to be able to make a (low fidelity) triangulation of a given surface with constant edge lengths (using equilateral triangles). This requirement limits the Gaussian curvature at each ...
0
votes
0answers
26 views

How do I change a 3d bspline curve to a polygon based graphic?

I have a graphics image generated with bsplines: Graphics3D[Tube[BSplineCurve[pts], 2]] I want to export this to a .stl file. To do so I know I need to modify ...

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