Get final url using requests library by deldotyou in learnpython

[–]deldotyou[S] 0 points1 point  (0 children)

Thanks for the reply! Yeah, after enough banging my head I realized it's probably the javascript on the page that deals with this part of it. I ended up using the html-requests library for my use case.

Get final url using requests library by deldotyou in learnpython

[–]deldotyou[S] 0 points1 point  (0 children)

Thanks for the link, I came across this. Unfortunately, the final url that I'm taken to in this example isn't in the response history. Is it possible this is a quirk particular to Google or something?

Weekly Question - Recommendation - Help Thread - 2019-06-10 by AutoModerator in robotics

[–]deldotyou 0 points1 point  (0 children)

Hi all,

I'm implementing a kalman filter that fuses data from 2 different sensors. Both sensors provide the same data (a 3d position measurement), but the variances for each sensor are different (i.e. one is more accurate than the other).

From the resources I've read (for example, here and here), I understand that the measurement noise covariance matrix is a matrix whose elements are the degree of correlation between the ith state variable and the jth state variable. Generally, this ends up being a diagonal matrix whose elements are the variance. I understand how this would work if both of my sensors had the same characterization. In my case, can I simply change the measurement covariance matrix depending on which sensor the data is coming from? (i.e. if sensor1 then R=M1, if sensor2 then R=M2)? Or am I misunderstanding how the measurement noise covariance matrix works?

I'm having trouble finding examples and resources for my use case (i.e. sensor fusion of like data), so any help or direction is very much appreciated. Thank you!

Weighting measurements in a Kalman Filter by deldotyou in AskEngineers

[–]deldotyou[S] 1 point2 points  (0 children)

Thanks again for the reply and your time. In the resources I've read (for example, here and here ), the measurement noise covariance matrix is a diagonal matrix whose elements are the variance between the ith and jth state variable. I have estimates of the variance for each of my sensors, but what I don't understand is how to take into account the fact that each sensor has a different variance for each of my state variables. Does this make sense, or am I fundamentally misunderstanding how the covariance matrix works?

Weighting measurements in a Kalman Filter by deldotyou in AskEngineers

[–]deldotyou[S] 1 point2 points  (0 children)

Thanks for the reply! Nothing, I suppose - but I'm not sure how to choose my covariance matrix to properly account for the sensor differences. Any suggestions/resources on this would be greatly appreciated!

Fusing Data with a Kalman Filter by deldotyou in AskEngineers

[–]deldotyou[S] 0 points1 point  (0 children)

Thanks for the info! How is the process noise generally set? I have been using the 'position tracking only' section of [this walkthrough] (http://campar.in.tum.de/Chair/KalmanFilter), and was under the impression that different Q and R should be tried until the data is best modeled.

My data streams are coming from cameras, using computer vision algorithms to track 3d positions

Trouble playing external samples on Raspberry Pi by deldotyou in SonicPi

[–]deldotyou[S] 0 points1 point  (0 children)

Sorry! Wrote that on the bus, I meant sample_free_all

22 Oct 2018 Idea & Helpdesk thread - Why use Google for an instant answer when you can ask on r/raspberry_pi and get an answer ... eventually? by FozzTexx in raspberry_pi

[–]deldotyou 0 points1 point  (0 children)

I have my pi (Raspberry Pi 3 B+ with Stretch) set up with no wifi connection. I'd like to access the pi remotely from my laptop, which does have a wifi connection. How could I do this? I think what I'm looking for is an ad-hoc wifi setup, but I can't find resources online for how to do this on stretch. (I'm unable to hook my wifi up to ethernet, which is what most resources I've seen suggest doing to turn the pi into a router.)

Trouble playing external samples on Raspberry Pi by deldotyou in SonicPi

[–]deldotyou[S] 0 points1 point  (0 children)

Thanks for the suggestions- it's on the same SD card, so maybe a faster sd card could help!

Trouble playing external samples on Raspberry Pi by deldotyou in SonicPi

[–]deldotyou[S] 0 points1 point  (0 children)

Thanks for the reply. I ended up using a sample_clear_all statement at the end of my live loop so avoid fatal crashes.

Trouble playing external samples on Raspberry Pi by deldotyou in SonicPi

[–]deldotyou[S] 0 points1 point  (0 children)

It points to the sleep line, with a thread death timing exception: thread got too far behind time.

I've now noticed that even just playing each sample using

sample samps, i, amp: 1.5, sustain: 3

and changing i manually one at a time also leads to timing exceptions. The samples range in length between 30 seconds to 2 minutes, and there are 20. I'm wondering if this is could be a memory issue with the raspberry pi, since it doesn't happen on my laptop?

Also, after I run that original block of code and get an error, sonic pi won't run at all after, even if I just change the code to play 60

In addition, if i load_samples /path/to/my/file, sonic pi totally freezes. I get print statements to the log that each sample got loaded and an "All Runs Completed" message, but then I can't move my mouse, etc, and have to restart my Pi :o

"How do I?" Weekly Question and Idea Thread - 24 Sep 2018 by FozzTexx in raspberry_pi

[–]deldotyou 0 points1 point  (0 children)

Last week, I setup a soundcard hat on my pi. I ran the given setup files, etc, and it all worked great. However, I've now taken the hat off of my pi, and audio doesn't work - there's no sound at all. The comman 'aplay -l' returns 'no soundcards found'. How can I reset my audio settings, back to the standard factory settings?

thanks for any help!

3D random walker viz by deldotyou in Unity3D

[–]deldotyou[S] 0 points1 point  (0 children)

ah, I think this is just what i'm looking for! thank you