================================== Top new questions this week: ==================================
[UI performance with large image data] http://mathematica.stackexchange.com/questions/127523/ui-performance-with-large-image-data
Some days ago, I built a small program for some of my colleagues to analyse cell images. One minor part of the user interface was the selection of the region of interest. The images are large and need ...
- asked by halirutan (25 votes), answered by Kuba (21 votes)
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[Transform sphere to an ellipse in \(R^2\)] http://mathematica.stackexchange.com/questions/127645/transform-sphere-to-an-ellipse-in-r2
In Lay’s Linear Algebra and Its Applications textbook, he defines the matrix \[A=\begin {bmatrix} 4 & 11 & 14\\8 & 7 & -2 \end {bmatrix}\] and claims that the transformation \(T(x)=A x\) ...
- asked by David (15 votes), answered by yarchik (17 votes)
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[Did Fibonacci slow down?] http://mathematica.stackexchange.com/questions/127876/did-fibonacci-slow-down
For Fibonacci numbers we have a nice formula:
\[ \frac {\left (1+\sqrt {5}\right )^n-\left (1-\sqrt {5}\right )^n}{2^{n} \sqrt {5}} \]
We can implement that in Mathematica:
a[n_]:= ...
- asked by Fred Simons (13 votes), answered by Szabolcs (20 votes)
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[I would like to create a fractal by copying, scaling and rotating the initial element] http://mathematica.stackexchange.com/questions/127458/i-would-like-to-create-a-fractal-by-copying-scaling-and-rotating-the-initial-el
I want to create a fractal, which looks like this:
This is rule 150R, which can be found in NKS, page 439.
However, instead of using a cellular automaton, I want to create this fractal from a ...
- asked by Yuriy S (13 votes), answered by wxffles (13 votes)
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[Mathematica + Pythonika on the Raspberry pi] http://mathematica.stackexchange.com/questions/127802/mathematica-pythonika-on-the-raspberry-pi
Due to the high availability of python code for the rpi, I’m trying to call python functions from Mathematica. I know that pythonika works well on OS X, but I can’t compile it on the Raspberry pi.
...
- asked by elbOlita (12 votes), answered by elbOlita (13 votes)
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[How to map and sum a list fast?] http://mathematica.stackexchange.com/questions/127658/how-to-map-and-sum-a-list-fast
The following takes a lot of memory and is slow:
Timing[Total[Map[#^2 &, Range[1, 100000000]]]]
I suspect this is because it first calculates and stores the whole list of squared numbers and ...
- asked by Yrogirg (12 votes), answered by BlacKow (19 votes)
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[Implementing the BihamMiddletonLevine traffic model as CellularAutomaton] http://mathematica.stackexchange.com/questions/127821/implementing-the-biham-middleton-levine-traffic-model-as-cellularautomaton
In an attempt to understand how to make rules for CellularAutomaton[], I set out to try to implement the BihamMiddletonLevine traffic model.
It is a 2D, k=3 model with a 3x3 neighborhood, so the ...
- asked by HJensen (10 votes), answered by C. E. (5 votes)
================================== Greatest hits from previous weeks: ==================================
[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/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 ...
- asked by Dr. belisarius (341 votes), answered by Michael E2 (197 votes)
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[How to make this beautiful animation] http://mathematica.stackexchange.com/questions/112700/how-to-make-this-beautiful-animation
How to make an animation of following gif in Mathematica?
Edit: The animation shown above was created by Charlie Deck in processing.
And how to make 3D analog?
I tried first few steps
line = ...
- asked by vito (47 votes), answered by C. E. (50 votes)
================================== Can you answer these? ==================================
[VectorPlot3D broken in Mathematica 11.0.1?] http://mathematica.stackexchange.com/questions/127724/vectorplot3d-broken-in-mathematica-11-0-1
Here is what I get when simply evaluating the example in the documentation:
This is on Win7 x64. I can see some vectors if I do something like
VectorPlot3D[{1, 1, 1}, {x, -1, 1}, {y, -1, 1}, {z, ...
- asked by Pirx (5 votes)
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[Least squares approximation] http://mathematica.stackexchange.com/questions/127806/least-squares-approximation
I have data points which is mydata = 0, 0, 1, 1, 2, 0;
From this data, I need to do the least squares approximation by using Bernstein polynomials to produce a set of Bezier points. Before ...
- asked by NKamaru (2 votes)
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[Matching key-value pair without converting to List in KeyValueMap] http://mathematica.stackexchange.com/questions/127860/matching-key-value-pair-without-converting-to-list-in-keyvaluemap
I frequently use this method with KeyValueMap in order to match and refer to named parts (ie, "myKey", "myValue")
EDIT: to refer to named parts in the function f without an external function ...
- asked by alancalvitti (1 vote)