3.3 Tuesday, January 2, 2018

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Top new questions this week: 
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[What’s the default colormap (or color scheme) used in mathematica?] https://mathematica.stackexchange.com/questions/162883/whats-the-default-colormap-or-color-scheme-used-in-mathematica

For example, the colors used on this page: http://reference.wolfram.com/language/ref/ContourStyle.html

or here: https://www.wolfram.com/mathematica/new-in-10/plot-themes/default.html

or here: ...

- asked by Alex (8 votes), answered by kglr (7 votes)

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[\({\frac {\partial ^{2} u}{\partial {x}^{2}}} +{\frac {\partial ^{2} u}{\partial {y}^{2}}} =0\) with one boundary at infinity] https://mathematica.stackexchange.com/questions/162691/frac-partial2-u-partial-x2-frac-partial-2-u-partial

Is there a trick to make Mathematica solve

\[{\frac {\partial ^{2} u}{\partial {x}^{2}}} +{\frac {\partial ^{2} u}{\partial {y}^{2}}} =0\] with one boundary condition at \(\infty \)?

Boundary ...

- asked by Nasser (8 votes), answered by ZufolgeWeierstrass (13 votes)

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[How to make simple closed curve that can be smoothly morphed using locators] https://mathematica.stackexchange.com/questions/162711/how-to-make-simple-closed-curve-that-can-be-smoothly-morphed-using-locators

Given a simple closed curve in 2D with some locators on it, I would like to have be able to stretch and squish parts of the curve by moving the locators to morph the curve into another simple closed ...

- asked by Michael McCain (8 votes), answered by halirutan (12 votes)

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[Approximation with radial basis functions] https://mathematica.stackexchange.com/questions/162768/approximation-with-radial-basis-functions

I want to approximate some functions with basisfunctions, which can be easy Fourier-transformed. So I got the idea to approximate my function with Gaussian normal-distribution curves. This led me to ...

- asked by pcalc (7 votes), answered by Anton Antonov (7 votes)

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[How to Discretize the Following Region Using Reasonable Bounds?] https://mathematica.stackexchange.com/questions/162674/how-to-discretize-the-following-region-using-reasonable-bounds

I want to accurately discretize the implicit equation \(x^2+x+y^2+\sin (4xy)+\sin (3xy)=3.9\).

To get the whole discretized shape, I’m forced to use oversized bounds x,-70,80 and y,-70,80

curve = ...

- asked by Arbuja (7 votes), answered by Carl Woll (5 votes)

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[Replacement for GraphJoin] https://mathematica.stackexchange.com/questions/162900/replacement-for-graphjoin

According to MathWorld » GraphJoin, Mathematica could compute the join of two graphs with the GraphJoin command, part of Combinatorica. This command no longer works as of v10, and I cannot find a ...

- asked by Bryan Clair (5 votes), answered by kglr (6 votes)

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[How can I make a DensityPlot3D over a triangle?] https://mathematica.stackexchange.com/questions/162852/how-can-i-make-a-densityplot3d-over-a-triangle

I know that I can plot over 3D-regions like balls via

DensityPlot3D[(x^2 + y^2 + z^2)^2, {x, y, z}  Ball[{0, 0, 0}, 1]]

But, not surprisingly, this breaks down for 2D-regions like triangles.

How ...

- asked by java4ever (5 votes), answered by rcollyer (7 votes)

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

[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 -> Quit kernel and firing a new one up?

- asked by niklasfi (66 votes), answered by Artes (63 votes)

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[How to calculate contour integrals with Mathematica?] https://mathematica.stackexchange.com/questions/34073/how-to-calculate-contour-integrals-with-mathematica

How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?

- asked by user64494 (31 votes), answered by Artes (54 votes)

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

[Apply a classifier to a column in excel and export side by side result?] https://mathematica.stackexchange.com/questions/162901/apply-a-classifier-to-a-column-in-excel-and-export-side-by-side-result

I’m relatively new to using Mathematica, and I was able to create a Classifier from a training set of about 3,000 pairs of non-numerical text strings.

I have my test set of about 20,000 records in an ...

- asked by M0RPH0RX (2 votes)

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[Solving a cumulative distribution from a first order condition] https://mathematica.stackexchange.com/questions/162825/solving-a-cumulative-distribution-from-a-first-order-condition

I could use some guidance in using Mathematica’s NDSolve. I’m attempting to numerically uncover a cumulative distribution function (CDF), \(F(p)\), with density \(f(p)\) from a first order condition, ...

- asked by J.R. (1 vote)

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[Fourier | Examples | Applications | Frequency Identification: high resolution: what trick is this?] https://mathematica.stackexchange.com/questions/162661/fourier-examples-applications-frequency-identification-high-resolution-w

My question is regarding one of the examples in the Documentation Center for the built-in symbol Fourier:

Fourier | Examples | Applications | Frequency Identification

Fourier is used to find the ...

- asked by Jack (1 vote)