2.5.2 Greatest hits from previous weeks

2.5.2.1 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)

2.5.2.2 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)