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##### Activity
• Nov 09 2020 13:10
labarba closed #217
• Nov 09 2020 12:27
Wajiha11 commented #217
• Nov 09 2020 12:27
Wajiha11 opened #217
• Dec 22 2019 20:45
mesnardo edited #216
• Dec 22 2019 20:44
mesnardo closed #216
• Dec 22 2019 20:44
mesnardo closed #215
• Dec 22 2019 20:44
mesnardo closed #213
• Dec 22 2019 20:44

mesnardo on master

Minor changes * [Module 2, Les… (compare)

• Dec 04 2019 01:43
mesnardo labeled #216
• Dec 04 2019 01:43
mesnardo opened #216
• Mar 12 2019 20:30
nightwolfer1 commented #174
• Mar 12 2019 19:32
labarba commented #174
• Mar 12 2019 18:33
nightwolfer1 commented #174
• Feb 21 2019 13:27
bknaepen synchronize #167
• Dec 09 2018 22:11
Chao8219 edited #214
• Dec 09 2018 22:09
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• Nov 27 2018 17:01
mesnardo opened #215
• Oct 03 2018 15:22
Chao8219 opened #214
• Oct 03 2018 00:03
Chao8219 opened #213
• Aug 30 2018 20:53

labarba on format

Lorena A. Barba
@labarba
We are planning to have some material on CUDA Python via Numba
aarrietac
@aarrietac
Starting the day with Pyhon :smile:
Ian Hawke
@IanHawke
Ah, we've gone to $\gamma$ for angles?
Hal Snyder
@DrXyzzy
There's a feature request open for MathJax here. :smile:
some discussion of it at gitterHQ/gitter
Lorena A. Barba
@labarba
We had a huge argument with all my students about signs, it lasted like two hours!
We should've had you, Ian: you're the mathematician!
The signs of the angles turns out to be important in the whole derivation, and we were mixing things: glide angle is always positive… the glider is assumed to be going down (as weight is the driving force opposing drag). But in the analysis of the particle in a curved path, we needed theta positive upwards!
Ian Hawke
@IanHawke
I think I clocked the positivity of z issue (NOTE: someone on the forum complained about the notebook throwing an assertion error; it's precisely the positivity of z that this is about, and I think should be expected). I was always thinking even functions in the small angle expansion, though, so I missed the sign issue.
Lorena A. Barba
@labarba
The explanations needed a little more precision, but the derivation is right.
We follow Milne-Thompson (1966) and I added a note explaining that. He uses theta for the trajectory angle, positive up. That carries to equations (10), where sin theta= - dz/ds … note minus
DrXyzzy --- did you request MathJax to be available within the markdown in Gitter?
Hal Snyder
@DrXyzzy
Yes.
Lorena A. Barba
@labarba
That would be nice.
@IanHawke -- We cannot reply in the forums right now: it's broken. But yes, the error in the trajectory plotting code is probably because of the parameters they picked.
Ian Hawke
@IanHawke
Yes - I've lost some long replies in the forums the past couple of days (when testing, I should remember to keep them short...).
Maybe we should set a mini-exercise to evaluate the energy loss due to numerical error?
GTG.
Lorena A. Barba
@labarba
I've got that written up!!! (and it's actually an energy gain)
Actually, what I have written up is just the proof that T_{n+1}=T_n(1 + w^2 Delta t ^2) -- one page of algebra
But you suggest giving that to students to do?
Sigurd Angenent
@SigurdAngenent
Hi, thanks for running this MOOC. It seems like quite a project. I think that the first python script can be simplified. In phugoid.py you compute the radius of curvature, the center of the osculating circle and then rotate the point by a small angle. But you could also use the diffeqs dx/ds = cos(theta) and dz/ds=sin(theta) to increment x and z
Sigurd Angenent
@SigurdAngenent
OK, the indentation in my previous post is gone. I don't see how to do that. I don't understand github wel enough to upload the modified-phugoid.py file..
Alistair Walsh
@alistairwalsh
github is not exactly intuitive :-) I would suggest a tutorial like https://try.github.io/levels/1/challenges/1
aarrietac
@aarrietac
Yeah! This is an amazing tutorial for git! Thanks @alistairwalsh :clap:
scshepard
@scshepard
Anaconda install observation; I'm using the Prof recommended site (https://store.continuum.io/cshop/anaconda/) but fell into a couple of Dark Places; first, the user interface is "odd"; suggest you "hover" over the link to verify the file name before clicking. Also (it may be a Windows or Windows 8.1 issue) had to edit the system PATH because Anaconda set its self as a "user" not system install (i.e: Had to delete the old python PATH in system; it is in my user PATH, but system PATH over-rode it). Now, all works great! (for what it's worth, I'm running Python 3.4)
Lorena A. Barba
@labarba
anyone there wish to test our new installation ???
I need testers
We're testing a new course platform for the course, with the latest version of Open edX and will migrate the course tomorrow if all tests pass!!!
Help!
Uncustomized with our style, but all course state until last Friday in the new installation: Please try to break it ....
within reason ...
Lorena A. Barba
@labarba
if it passes, we'll add the custom style, delete the course and re-migrate it from the live version.
Alistair Walsh
@alistairwalsh
I can check, what exactly do you want me to install. I have native Mac, Linux and Windows as well as virtual machines. Does it need to be full native or is installing on the virtual machines enough?
login/password from the old site doesn't work with the new one. Is that what you expected?
Lorena A. Barba
@labarba
Nothing to install ... when did you register? They migrated the course state from last Friday, so if you registered after that, it wouldn't have you.
But my credentials from the previous course worked just fine. It should recognize any users that signed up until Friday morning.
I just want people to make test posts on the forum, upload an image, pin, flag, +1, etc.
Alistair Walsh
@alistairwalsh
I can access the old site, I can access the new site but had to create a new profile
I'm just going to check my login details and make sure I'm entering the right info...
Also didn't receive the confirmation email the site said it was sending with the new account.
Yurlungur
@Yurlungur
Hi this is Jonah from the discussion forum. I can access the new site and use the discussion forum. However, the new site rejected my credentials from the old site. And when I tried to register with my old username, it told me someone was already registered. I made a new profile so it doesn't matter, but I wonder if there's something wrong with your database?
Alistair Walsh
@alistairwalsh
I'm also not receiving the confirmation email the new login should have generated. The site gives a message that it sent a second one, not received
Alistair Walsh
@alistairwalsh
I was using the old site before Friday
Lorena A. Barba
@labarba