5.31 Tuesday, May 31, 2016

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Top new questions this week: 
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[Determine whether points lie within a cow] http://mathematica.stackexchange.com/questions/116160/determine-whether-points-lie-within-a-cow

I would like to determine whether randomly-generated points

lX = RandomVariate[UniformDistribution[{-0.4, 0.4}], {1000}]; 
lY = RandomVariate[UniformDistribution[{-0.2, 0.2}], {1000}]; 
lZ =  ... 

- asked by ben18785 (18 votes), answered by Daniel Lichtblau (12 votes)

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[FindMinimum doesn’t increase step size when necessary] http://mathematica.stackexchange.com/questions/116295/findminimum-doesnt-increase-step-size-when-necessary

I’ve spent much time finding a minimal example demonstrating this problem with FindMinimum. Normally one faces this problem when fitting very large and complicated functions which cannot be posted ...

- asked by Alexey Popkov (13 votes)

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[Internal DynamicModule steals scope of external DynamicModule] http://mathematica.stackexchange.com/questions/116167/internal-dynamicmodule-steals-scope-of-external-dynamicmodule

I have two dynamic objects, one nested in the other. Both have their own functions defined, as follows. I have simplified them to the point where they don’t make much sense, but can still illustrate ...

- asked by Istvan Zachar (13 votes), answered by John Fultz (6 votes)

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[Opposite of Alternatives in a Rule] http://mathematica.stackexchange.com/questions/116302/opposite-of-alternatives-in-a-rule

Mathematica provides Alternatives, to match one of several patterns.  In a rule, 
this is used as p1|p2|p3:>replacement.  I would like to have the 
opposite logic: p1&p2&p3:>replacement  ...

- asked by Bruno Le Floch (10 votes), answered by Bruno Le Floch (8 votes)

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[Symbolic and numeric limit disagreeing on branch cut of ArcTan] http://mathematica.stackexchange.com/questions/116183/symbolic-and-numeric-limit-disagreeing-on-branch-cut-of-arctan

Bug introduced after v8.0.4 and before v9.0.1, and persisting through v10.4.1.

Investigating comments to my previous question lead me to the following problem:

 N[Limit[ ArcTan[Sqrt[-4 E^(I a)]],  ...

- asked by Axel Boldt (9 votes), answered by bbgodfrey (9 votes)

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[Why does the global variable exist here, where it was declared only in Module?] http://mathematica.stackexchange.com/questions/116140/why-does-the-global-variable-exist-here-where-it-was-declared-only-in-module

Why does Mathematica choose the mechanism that makes the global variable a here while parsing?

In 
 
f := Module[{a}, a;] 
 
 
In 
 
?a 
 
 
Out 
 
Global`a

I don’t understand why Mathematica goes in the way ...

- asked by Smart Humanism (8 votes), answered by Leonid Shifrin (15 votes)

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[Integrate and NIntegrate disagreeing over branch cut of Sqrt?] http://mathematica.stackexchange.com/questions/116041/integrate-and-nintegrate-disagreeing-over-branch-cut-of-sqrt

Bug introduced after v8.0.4 and before v9.0.1, and persisting through v10.4.1.

In Mathematica 10.2 I’m trying to integrate this piecewise continuous function, but Integrate and NIntegrate seem to ...

- asked by Axel Boldt (8 votes), answered by bbgodfrey (6 votes)

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

[Generating a Sierpinski carpet] http://mathematica.stackexchange.com/questions/22052/generating-a-sierpinski-carpet

I am trying to draw a Sierpinski_carpet. I have code that works, but I think there is a more elegant way to do than my way. Maybe I couls use Tuples or Permutations or some similar function to ...

- asked by chyaong (43 votes), answered by Mr.Wizard (67 votes)

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[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral

Here is a start. I’m looking for a nice way to draw it.

Graphics[{EdgeForm[Black], White, 
  Polygon @ {{0, 0}, {-1, 0}, 
    Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, 
  Polygon @ {{0,  ...

- asked by mathe (22 votes), answered by Bob Hanlon (18 votes)

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

[Problem with Parallelization when using Packages] http://mathematica.stackexchange.com/questions/115862/problem-with-parallelization-when-using-packages

I tried to find a solution to my problem in several answers posted in MSE but due to lack of my knowledge on parallelization territory, I couldn’t figure out solution to my problem.

I have a big code ...

- asked by Algohi (4 votes)

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[Fourier transform of Exp[x]/x] http://mathematica.stackexchange.com/questions/116157/fourier-transform-of-expx-x

Could you please explain why Mathematica gives the following expression when taking Fourier transform of \(\exp (\lambda z)/\lambda \)? \[\frac {-\log (-z)+\log (z)}{\sqrt {2\pi }}\] Why the answer does not ...

- asked by Ivan Gankevich (4 votes)

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[Inconsistent behavior from RegionMeasure on the RegionIntersection between a Polygon and a Line] http://mathematica.stackexchange.com/questions/116083/inconsistent-behavior-from-regionmeasure-on-the-regionintersection-between-a-pol

Consider a Polygon with lines drawn between two of its vertices,

pgon = Get[ 
    "https://gist.githubusercontent.com/jasondbiggs/\ 
59cb7d4aa802bde68c9f6a5203ef698f/raw/\ 
 ...

- asked by Jason is no longer a postdoc (1 vote)