8.29.2 Greatest hits from previous weeks

8.29.2.1 How do I identify the source of a "Tag times protected" error?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982

I have some code that looks like 
 
 Table[ 
a = 1; 
b = {2, 3} 
c = i;, 
{i, 2} 
] 
 
 
which gives an error: 
Set::write: Tag Times in c {2,3} is Protected.... 
[warning-messages] [syntax] [debugging] [faq]
 

asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 Score of 31

answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 Score of 37

8.29.2.2 How to plot an ellipse?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100

I'm new to Mathematica, and I'm finding it difficult to plot an ellipse. 
I tried using 
 
 Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}] 
 
 
but I'm getting ... 
[plotting]
 

asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 Score of 19

answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 Score of 32

8.29.2.3 Plot data from txt file?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910

I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4? 
[plotting] [import]
 

asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 Score of 21

answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 Score of 24

8.29.2.4 Where can I find examples of good Mathematica programming practice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ... 
[reference-request] [programming]
 

asked by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 589

answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 Score of 516

8.29.2.5 Standard deck of 52 playing cards in curated data?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108

I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included? 
 
If not, is there a way ... 
[curated-data]
 

asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 Score of 26

answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 Score of 24

8.29.2.6 Is there something like DensityPlot3D to visualize atomic orbitals?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378

I'm visualizing some hydrogen like atomic orbitals.  For looking at plane slices of the probability density, the  DensityPlot  function works well, and with something ... 
[plotting] [physics] [chemistry]
 

asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 Score of 45

answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 Score of 26

8.29.2.7 How can I plot implicit equations?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668

If you enter the following into Wolfram | Alpha, you get nice graphs: 
 
 graph 4 x^4 + y^2 = 2 
 
How do you do this in Mathmatica? I realize that these are not ... 
[plotting] [faq]
 

asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 Score of 41

answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 Score of 42