6.5 Tuesday, December 1, 2015

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Top new questions this week: 
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[Wiggly and imprecise animated gif output] http://mathematica.stackexchange.com/questions/100628/wiggly-and-imprecise-animated-gif-output

Trying to make animated gif of zooming into famous Ford circles. With the code

visibleQ[lh_, hr_, c_, k_] := Which[ 
  lh >= 1/(2 k), If[2 c k^2 <= 1 && lh^2 < c (1 - c k^2), True,  ... 
 
- asked by   (12 votes), answered by Michael E2 (7 votes)

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[What is the difference between Dynamic[x] and Dynamic[ h[x] ] for DynamicModule variables?] http://mathematica.stackexchange.com/questions/100828/what-is-the-difference-between-dynamicx-and-dynamic-hx-for-dynamicmodule

Why plain Dynamic[x] is less sensitive and less likely to automatically be updated than e.g. Dynamic[x]?

The issue was raised here couple of times but I don’t remember any general answer, just work ...

- asked by Kuba (11 votes)

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[Pick elements from list "separately"] http://mathematica.stackexchange.com/questions/100696/pick-elements-from-list-separately

I have the following list I want to pick elements from:

mylist = 1, 5, 7, 3, 4, 7, 2, 9, 9, 1, 10, 12, 2, 64, 34, 64

I have another list with 0’s and 1’s which is my selector:

selector = 1, 1, ...

- asked by holistic (11 votes), answered by eldo (11 votes)

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[A quicker than outer] http://mathematica.stackexchange.com/questions/100551/a-quicker-than-outer

I need to get a matrix \(\{a(x_i-x_j)\}\), where \(x_i\) form a partition of an interval, \(a(x)\) is a given function. I use

In[67]:= a[x_?NumericQ] := N[Exp[-Abs[x]]]; 
         x = Table[-10 + 0.02 (j -  ...

- asked by Dmitri (11 votes), answered by Szabolcs (14 votes)

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[Converting a list of rules to a list of lists] http://mathematica.stackexchange.com/questions/100700/converting-a-list-of-rules-to-a-list-of-lists

What are some easy ways to convert the list of Rules

{"Joe" -> 94, "Jane" -> 85, "Bob" -> 82, "Bill" -> 83, 
 "Michelle" -> 98} 
 
into a list of lists: 
 
 ...

- asked by David (9 votes), answered by eldo (14 votes)

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[Magnifying Glass on a Plot] http://mathematica.stackexchange.com/questions/100691/magnifying-glass-on-a-plot

Although there is a trick in TEX magnifying glass but I want to know is there any function to magnifying glass on a plot with Mathematica?

For example for a function as Sin[x] and at x=Pi/6

Below, ...

- asked by Ackaran (9 votes), answered by Karsten 7. (13 votes)

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[How to extract a region shape from an 2 colour image?] http://mathematica.stackexchange.com/questions/100578/how-to-extract-a-region-shape-from-an-2-colour-image

I’ll start by saying that I don’t know anything about image processing. I have an image and I need to extract its outermost shape for use in a WordCloud. The image only has two colours and the ...

- asked by Edmund (9 votes), answered by nikie (4 votes)

================================== Greatest hits from previous weeks: ==================================

[How to express trigonometric equation in terms of of given trigonometric function?] http://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio

How can I express a trigonometric equation / identity in terms of a given trigonometric function?

using following trigonometric identities

Sin[x]^2+Cos[x]^2==1 
Sin[x]/Cos[x]==Tan[x] 
 ...

- asked by Prashant Bhate (24 votes), answered by Simon (28 votes)

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[How to find all the local minima/maxima in a range] http://mathematica.stackexchange.com/questions/5575/how-to-find-all-the-local-minima-maxima-in-a-range

I want to find :

all local maxima in range 
all local minima in range

From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...

- asked by Margus (52 votes), answered by Daniel Lichtblau (56 votes)

================================== Can you answer these? ==================================

[Solving this system of nonlinear equations] http://mathematica.stackexchange.com/questions/100466/solving-this-system-of-nonlinear-equations

Edit Interestingly, I realized solving my problem with \(2n\) equations appeared to be more efficient than using mathematical results on the solutions to reduce the problem to \(n\) equations (the \(n\) ...

- asked by anderstood (2 votes)

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[Share variables among notebooks with different Kernels] http://mathematica.stackexchange.com/questions/100760/share-variables-among-notebooks-with-different-kernels

So I have a server running in another notebook with a secondary kernel. I run my main notebook and launch the server notebook, but I have configured the variables in my main one, and can’t find a way ...

- asked by jaimehrubiks (2 votes)

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[Planning flights for a special route] http://mathematica.stackexchange.com/questions/100768/planning-flights-for-a-special-route

I want to plan a world trip with Mathematica. So I already have the dataset with all the cities I want to visit and the tour (with the command FindShortestTour). So now I want to know how to come from ...

- asked by Kristina (3 votes)