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phetsims / wave-on-a-string

"Wave on a String" is an educational simulation in HTML5, by PhET Interactive Simulations.
http://phet.colorado.edu/en/simulation/wave-on-a-string
GNU General Public License v3.0
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Pulse wave amplitude is inconsistent with low tension and low pulse width. #44

Closed orejolaphet closed 8 years ago

orejolaphet commented 10 years ago

The amplitude of the pulse wave is inconsistent in a succession of pulses with the following conditions: Amplitude: 3 cm Pulse width: 0.16s Damping: none Tension: low The succession of wave pulses vary in height. screen shot 2014-01-31 at 2 39 21 pm

jonathanolson commented 10 years ago

This is caused by the sampling frequency being much lower than the pulse frequency.

Instead of sampling the pulse form at a specific time, we can integrate the pulse over the time the last frame took, however due to aliasing we may still have pulses that look "wider but shorter".

There may be a somewhat-complicated way to start pulses aligned to the string beads every time, but we could also consider limiting the pulse widths to larger values (possibly just when the tension is low).

jonathanolson commented 10 years ago

Last resort: Change minimum pulse width to 0.3

orejolaphet commented 10 years ago

Occurs in 0.0.0-dev.14. Reopening

ariel-phet commented 8 years ago

parameters in published version do not allow this condition, issue not observed. Closing.