4.14 Tuesday, September 19, 2017

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Top new questions this week: 
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[Pop-up appeared and then disappeared during first documentation search in 11.2] https://mathematica.stackexchange.com/questions/155717/pop-up-appeared-and-then-disappeared-during-first-documentation-search-in-11-2

After installing Mathematica 11.2, the first time I searched for something in the help center a pop-up appeared and then disappeared. It didn’t appear on a subsequent search, even if I restarted ...

- asked by Itai Seggev (23 votes), answered by Itai Seggev (26 votes)

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[ExternalEvaluate for Python fails with Import::nopythonevals] https://mathematica.stackexchange.com/questions/155821/externalevaluate-for-python-fails-with-importnopythonevals

I tried using ExternalEvaluate on OS X with Anaconda Python, and every ExternalEvaluate call failed with the Import::nopythonevals message. This happened even though an external evaluator was ...

- asked by Szabolcs (15 votes), answered by Szabolcs (12 votes)

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[Visualizing a holomorphic bijection between the unit disc and a domain] https://mathematica.stackexchange.com/questions/155954/visualizing-a-holomorphic-bijection-between-the-unit-disc-and-a-domain

One can construct a holomorphic bijection between the (open) unit disc \(D=\{z\in {\bf C}: |z|<1\}\), and a domain \(D\setminus \overline {B_{1/2}(-1/2)}\) where \(B_r(z_0)\) denotes the ball of radius \(r\) ...

- asked by Jack (12 votes), answered by Michael E2 (13 votes)

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[How to create search indices for custom documentation pages?] https://mathematica.stackexchange.com/questions/155932/how-to-create-search-indices-for-custom-documentation-pages

I have a package that uses custom documentation pages that are not generated with Wolfram Workbench.

How can I create search indices for these pages?

Requirements:

Searching should work in ...

- asked by Szabolcs (10 votes), answered by Szabolcs (1 vote)

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[Compile M11.1-compatible LibraryLink libraries using M11.2] https://mathematica.stackexchange.com/questions/155940/compile-m11-1-compatible-librarylink-libraries-using-m11-2

WolframLibraryVersion, defined in WolframLibrary.h, was bumped from 3 to 4 in Mathematica 11.2. This causes libraries compiled with M11.2 to fail to load in earlier versions.

Is it possible to ...

- asked by Szabolcs (9 votes)

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[How to insert dimensions in graphics?] https://mathematica.stackexchange.com/questions/155677/how-to-insert-dimensions-in-graphics

I’m creating figures (a T beam section) using the Graphics function. Like this:

a = Graphics[Polygon[{{0, 80}, {0, 85}, {100, 85}, {100, 80}}]]; 
b = Graphics[Polygon[{{47.5, 80}, {52.5, 80}, {52.5,  ...

- asked by Diogo (9 votes), answered by wxffles (10 votes)

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[Mathematica 11.2 Import Statement Produces Errors & Truncates CSV Data Created in 11.1] https://mathematica.stackexchange.com/questions/155908/mathematica-11-2-import-statement-produces-errors-truncates-csv-data-created-i

Bug introduced in 11.2.0

TL;DR 
 
 
Issue 1 (bug): Import of CSV files with column specification fails 
when "HeaderLines" or "SkipLines" option is used: 
 
Import["ExampleData/financialtimeseries.csv",  ... 

- asked by Joseph Karpinski (8 votes), answered by Itai Seggev (8 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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[How do I clear all user defined symbols?] https://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols

Is there some way to do this other than going to Evaluation -&gt; Quit 
kernel and firing a new one up?

- asked by niklasfi (55 votes), answered by Artes (54 votes)

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

[Covariant derivative given Christoffel symbols] https://mathematica.stackexchange.com/questions/155871/covariant-derivative-given-christoffel-symbols

I’ve been trying to take covariant derivative of various quantities along various surfaces in Mathematica, but I keep running into issues, frequently I get a tensor with the wrong dimension. Using the ...

- asked by Noahb32 (1 vote)

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[How to pass in-memory images through ExternalEvaluate?] https://mathematica.stackexchange.com/questions/156051/how-to-pass-in-memory-images-through-externalevaluate

Version 11.2 has a new import/export format PythonExpression.

Unfortunately, it doesn’t work out-of-the-box with images:

And using the ImageData directly is too slow:

Anyhow, I have some image ...

- asked by M.R. (4 votes)

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[GeneralizedLinearModelFit IRwLS] https://mathematica.stackexchange.com/questions/155692/generalizedlinearmodelfit-irwls

I’m interested in Mathematica’s capabilities with regard to robust fitting vs. outliers. In the Statistical Model Analysis Tutorial under the Generalized Linear Models section heading, there is this ...

- asked by Chris Chiasson (1 vote)