4.27 Tuesday, June 20, 2017

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Top new questions this week: 
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[Good references for parallel programming in Mathematica] https://mathematica.stackexchange.com/questions/148489/good-references-for-parallel-programming-in-mathematica

There are plenty of good references for all sorts of Mathematica programming:

This forum is a great example for specific questions/"getting things done". Books like those by R.Maeder (esp. the now ...

- asked by Gaius (17 votes)

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[Dot not well-defined: are there better examples?] https://mathematica.stackexchange.com/questions/148465/dot-not-well-defined-are-there-better-examples

Dot is not "well-defined" in Mathematica - we cannot simultaneously have it being associative and working with 1D and 2D arrays. For example, the order we substitute for variables should not change ...

- asked by mikado (10 votes), answered by Shadowray (9 votes)

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[Internal‘Bag memory usage] https://mathematica.stackexchange.com/questions/148594/internalbag-memory-usage

1. How does Internal‘Bag handle memory inside a compiled function? (examples below)

2. Is there a way to explicitly free up memory used by Internal‘Bag without exiting the function?

Preface: The ...

- asked by aardvark2012 (9 votes)

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[Preventing an unwanted vertical line from appearing my plot] https://mathematica.stackexchange.com/questions/148502/preventing-an-unwanted-vertical-line-from-appearing-my-plot

How can I eliminate (remove) the unwanted vertical line x = 1 when I make the plot shown below.

p3 = 
  Plot[ 
    {0.5/(-0.1 x + 0.1), 
     0.04/(-0.004 x + 0.004), 
     1.359/(-0.08 x + 0.08), 
    ...

- asked by Irreversible (9 votes), answered by m_goldberg (1 vote)

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[Integer to Alpha Representation] https://mathematica.stackexchange.com/questions/148446/integer-to-alpha-representation

I wanted a nice way to convert natural numbers to alphabetic representations like:

1->"A", 
2->"B", 
... 
26->"Z", 
27->"AA, 
... 
26*2->"AZ", 
26*2+1->"BA", 
...

And I knew this was ...

- asked by b3m2a1 (8 votes), answered by Carl Woll (6 votes)

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[How to display numbers as multiples of a square root] https://mathematica.stackexchange.com/questions/148551/how-to-display-numbers-as-multiples-of-a-square-root

The extension field \(\mathbb {Q}(\sqrt {2} + \sqrt {3})\) can be represented by a \(4\) - dimensional vector space over \(\mathbb {Q}\) with basis \(\{1, \sqrt {2}, \sqrt {3}, \sqrt {6}\} \).

I made a matrix ...

- asked by nilo de roock (8 votes), answered by Carl Woll (7 votes)

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[Visually permute rows of a matrix via mouse dragging] https://mathematica.stackexchange.com/questions/148448/visually-permute-rows-of-a-matrix-via-mouse-dragging

I’m looking for a way to permute the rows of a matrix visually via mouse dragging, for example by clicking and dragging on a row in the MatrixPlot corresponding to the matrix.

What would be the best ...

- asked by glS (8 votes), answered by glS (10 votes)

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

[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] https://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value

I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,

u[x_] := Sqrt[2/L] * Sin[Pi * n * x / L]

and then ...

- asked by Matthew Brunetti (17 votes), answered by SquareOne (11 votes)

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[Entering numbers in Scientific Notation?] https://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation

I need to play with a lot of powers such as 10^-3. 1E-3 
does not work for it. Is there any short form for it?

- asked by hhh (32 votes), answered by Rahul (43 votes)

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

[Which method should I use for a numerical triple Integration?] https://mathematica.stackexchange.com/questions/148629/which-method-should-i-use-for-a-numerical-triple-integration

Which method should I use for this numerical integration? Does it converge?

My constants are:

P = 10.5; 
m = 48.2; 
c = 1; 
 = 0.01; 
V0 = 10; 
EE = 2.3; 
II = 1.; 
k = 68.9*10^3; 
 
 
My Integration is 
 
    ...

- asked by Edmond Muho (2 votes)

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[possible memory problem with WatershedComponents] https://mathematica.stackexchange.com/questions/148318/possible-memory-problem-with-watershedcomponents

This could be regarded as a follow-up question to a previous post of mine (link).

When I use the WatershedComponents function on a large image (about 6000 x 10000 pixels) Mathematica comes up with an ...

- asked by Kardashev3 (4 votes)

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[Swedish characters in Databin] https://mathematica.stackexchange.com/questions/148550/swedish-characters-in-databin

I want to store strings with Swedish characters like å, ä and ö in a Databin, but get the following result:

bin = CreateDatabin[]; 
DatabinUpload[bin, {"a", "ä"}]; 
Values[bin] 
{a,"a""}

Does anyone ...

- asked by Sverker (5 votes)