APS Excellence in Physics Education Award
November 2019

Education Prize Logo
Science SPORE Prize
November 2011

NSF Logo
The Open Source Physics Project is supported by NSF DUE-0442581.

Multiple position/velocity values recorded for a single time value? post and replies

Return to the Multiple position/velocity values recorded for a single time value? thread
Login to post to this thread

Tracker plotting two position values on one time value?
Oscar W
3 Posts

I've been running into this issue with Tracker for a little while now.

Basically, whenever I'm placing down point masses, Tracker will plot subsequent points on the same time value, but only two at a time. This can be seen in the attached image. I've looked through the Tracker settings and through other forum posts, but I can't figure out why this is occurring. My guess is some issue with the frame data when I imported the video file, but I'm unsure.

https://imgur.com/LzEl9ce

Any help is appreciated.


Replies to Tracker plotting two position values on one time value?

Re: Tracker plotting two position values on one time value? -
Paul Nord
30 Posts

Can you also share the video file which produced this?

I've seen many strange video behaviors when stepping backwards through the video.  And just once I saw a frame that seemed to be out of order when stepping forwards through a video.  It's usually easy to just ignore the odd video and collect some other data.  Sometimes, obviously, the data can't be easily recreated.

Paul



Re: Tracker plotting two position values on one time value? -
Oscar W
3 Posts

Here's a Mega link to the files, since the forum upload limit is 2MB. I've included the video files as well as the Tracker project file:

https://mega.nz/file/UJc3BKBT#tm631f1ohgE9frWdU1MxN6kUlCnaWqoP9EUy26nifXQ

Let me know if you need anything else and thanks again for any help!



Re: Tracker plotting two position values on one time value? -
Oscar W
3 Posts

Quick update: I noticed that this has been happening for nearly all of the videos that I import into Tracker. I think it may be some issue with the way I'm recording it, but there don't seem to be any issues with it until it's actually imported into Tracker.

Any help/tips are appreciated, thanks!
'



OSP Projects:
Open Source Physics - EJS Modeling
Tracker
Physlet Physics
Physlet Quantum Physics
STP Book