8.22.2 Greatest hits from previous weeks

8.22.2.1 How to plot an ellipse?
8.22.2.2 Using Export[] sends the file where?
8.22.2.3 How do I plot a plane EM wave?
8.22.2.4 Positioning axes labels
8.22.2.5 Plotting a Phase Portrait
8.22.2.6 Image processing: Floor plan - detecting rooms' borders (area) and room names' texts
8.22.2.7 How to make an inkblot?
8.22.2.1 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
8.22.2.2 Using Export[] sends the file where?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586

I am trying to use the  Export  command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can't find the file! Where is it ... 
[export]
 
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 Score of 41
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 Score of 56
8.22.2.3 How do I plot a plane EM wave?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987

I would like to display an electromagnetic (EM) wave.  I have written code that works, but it does not "shade" the area between the graph and the axes.  Both the ... 
[graphics] [physics] [visualization]
 
asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 Score of 23
answered by J. M.'s persistent exhaustion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 Score of 17
8.22.2.4 Positioning axes labels

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388

I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I'd also like the x-axis label to be in the middle of the x-axis rather than ... 
[plotting] [graphics]
 
asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 Score of 15
answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 Score of 17
8.22.2.5 Plotting a Phase Portrait

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160

I'm trying to plot a phase portrait for the differential equation 
$$x'' - (1 - x^2) x' + x = 0.5 \cos(1.1 t)\,.$$ 
The primes are derivatives with respect to $t$. I've reduced this second order ODE to ... 
[plotting] [differential-equations]
 
asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 Score of 43
answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 Score of 41
8.22.2.6 Image processing: Floor plan - detecting rooms' borders (area) and room names' texts

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546

Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans. 
 
The problem 
 
... 
[image-processing]
 
asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 Score of 65
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 Score of 60
8.22.2.7 How to make an inkblot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.'s Rorschach demonstration): 
 
... 
[graphics] [performance-tuning] [image-processing] [generative-art]
 
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 Score of 88
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 Score of 52