PhET
Progress Report
Sam
Reid
June
4, 2009
An
online version of this report is available here.
Here's
a pie
chart representation of the time distribution.
I'll
be out of town and away from email June 8-23.
CCK
·
New
version here 3.17.02
·
Physics
algorithm has been rewritten in Scala
·
Old
version caused many bugs, including the one Kathy reported recently and many bugs
for capacitors/inductors. See #1678,
#1669, #1333, #1166, #1211, #409, #407, #406, #367, #687, #360
·
Benefits
of the new implementation
1.
Direct
support for zero resistance components; the previous version is very buggy and
resorts to awkward approximations when it comes to wires or components that are
supposed to have no resistance or very small resistance.
2.
Obtain
all node voltages and currents directly when there are multiple disconnected
circuits; former implementation did complicated and unnecessary graph
computations to split into connected components then solve each component
independently.
1.
Implementation
is simpler and easier to understand
2.
Easier
to write and run automated tests to ensure accuracy; tests are consolidated,
easy to read and easy to build on
3.
Outputs
the equations used for resistive circuit analysis directly to facilitate
understandability and debugging (learned this trick when I developed the model
for Density sim)
4.
Time
is handled uniformly, instead of using many workarounds and hacks.
·
Still
several things to be done:
1.
Performance
improvements, mainly will be by increasing simulation time step
2.
Extensive
testing
3.
Several
sign errors I can't account for
4.
Prototyping
in Scala saved a significant amount of time (compared to if I had originally
developed the new solution in Java), but we need to discuss whether this should
remain Scala or be rewritten in Java.
Energy
Skate Park
·
Many
fixes for internationalization, new version here
·
Todo:
1.
Hide options and track menus
2.
Fix the order of units and
numbers
3.
What is priority for the above?
Misc
·
Collaborated
with John on time model for Radioactive Dating Game
Upcoming Work
·
Bugfixes
for CCK physics
·
Test
resource deployment
·
Continue
model for density sim (object editor, movable scales, spherical objects, etc)
·
JMonkeyEngine/Xith/Jogl/3dzzd
·
Remove
buffering from PSwing
·
Ramp
Simulation, fixes and updates, including charts
·
For
details, See ticket report "Sam R: Report" here
