================================== Top new questions this week: ==================================
[New behavior of PlotRange in Mathematica 10] http://mathematica.stackexchange.com/questions/87808/new-behavior-of-plotrange-in-mathematica-10
In Mathematica 10, when I plot data that has small changes around some non-zero value, the plot chooses a PlotRange that "collapses" the data so that the variations cannot be seen. The only way I can ...
- asked by Greg Cook (17 votes), answered by Mr.Wizard (13 votes)
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[Simple Matrix multiplication takes very long] http://mathematica.stackexchange.com/questions/87857/simple-matrix-multiplication-takes-very-long
Bug introduced in 10.1.0
I came across some strange behaviour during a computation involving matrices with symbolic values. It is reproduced below.
Multiplying a random 30x30 array with symbolic ...
- asked by A. Roy (14 votes)
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[Why does leaving and re-entering a context lose values defined in that context?] http://mathematica.stackexchange.com/questions/88147/why-does-leaving-and-re-entering-a-context-lose-values-defined-in-that-context
I’m getting unexpected behavior when beginning a new context, leaving it, and then re-entering it. Specifically, when re-entering the context, symbols that had been previously defined in that context ...
- asked by ibeatty (12 votes), answered by Simon Rochester (13 votes)
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[Use of Key to extract a key value in Associations not working in V10.1] http://mathematica.stackexchange.com/questions/88034/use-of-key-to-extract-a-key-value-in-associations-not-working-in-v10-1
V10.1:
<|a -> 1|>[Key @ a] (* Missing["KeyAbsent", Key[a]]*) V10.0: <|a -> 1|>[Key @ a] (* 1 *)
Bug or Design Change?
- asked by Ronald Monson (11 votes), answered by Szabolcs (8 votes)
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[Using Mathematica to solve a probability problem] http://mathematica.stackexchange.com/questions/88178/using-mathematica-to-solve-a-probability-problem
The problem is from Principles of Statistics by M.G. Bulmer:
In a certain survey of the work of chemical research workers, it was found, on the basis of extensive data, that on average each man ...
- asked by billc (10 votes), answered by ciao (11 votes)
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[What does this message mean and how serious is it?] http://mathematica.stackexchange.com/questions/87891/what-does-this-message-mean-and-how-serious-is-it
I had some Mathematica files on over which recently I have faced to this message:
However, after searching, I have seen some blogs in Mathematica SE or in somewhere else about that, but I could not ...
- asked by mr.0093 (9 votes), answered by Mr.Wizard (17 votes)
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[Remove static objects from an image sequence] http://mathematica.stackexchange.com/questions/87901/remove-static-objects-from-an-image-sequence
Is it possible to remove static objects/pixels from a sequence of images?
Lets say I have a black square in the middle of my white picture (white background) and a black circle is orbiting around it. ...
- asked by PH13 (9 votes), answered by Pickett (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Multivariable Taylor expansion does not work as expected] http://mathematica.stackexchange.com/questions/15023/multivariable-taylor-expansion-does-not-work-as-expected
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \]
- asked by matheorem (15 votes), answered by Jens (21 votes)
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[How to ask Mathematica to imitate Andy Warhol’s pop-art painting?] http://mathematica.stackexchange.com/questions/59132/how-to-ask-mathematica-to-imitate-andy-warhols-pop-art-painting
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
- asked by Putterboy (43 votes), answered by belisarius (50 votes)
================================== Can you answer these? ==================================
[How to add AccuracyGoal and PrecisionGoal options in a numerical function?] http://mathematica.stackexchange.com/questions/88182/how-to-add-accuracygoal-and-precisiongoal-options-in-a-numerical-function
There are many built-in functions that contain AccuracyGoal, PrecisionGoal and WorkingPrecision.
For instance
NSolve NSolve[x^3 + 2 x + 7 == 0, x, WorkingPrecision -> 40] {{x -> ...
- asked by Shutao Tang (4 votes)
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[What is the best way to take the Bourdet derivative?]http://mathematica.stackexchange.com/questions/87760/what-is-the-best-way-to-take-the-bourdet-derivative
Given a list of paired delta-time, delta-pressure, \((dt,dp)\), what might be the best approach to calculate the Bourdet derivative, described below? I am unclear how to manipulate elements of the ...
- asked by John (4 votes)
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[Dirichlet coefficients as limits: wrong] http://mathematica.stackexchange.com/questions/87766/dirichlet-coefficients-as-limits-wrong
Perhaps I should have included the word "bug" in my question. Here we go
There is a bug in this Limit
Limit[3^s (-1 - 2^-s + Zeta[s]), s -> \[Infinity]] (* 0 *) It should be 1 and there is a ... - asked by Dr. Wolfgang Hintze (7 votes)