hongshaorou/openrocket
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #442 from JoePfeiffer/fix-getAverageThrust

Browse Source 
Fix getAverageThrust (fixes issue #441)
This commit is contained in:
Wes Cravens 2018-09-29 14:56:28 -05:00 committed by GitHub
commit 7177ca422c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 14 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
core/src/net/sf/openrocket/motor/ThrustCurveMotor.java
View File

@ -313,34 +313,31 @@ public class ThrustCurveMotor implements Motor, Comparable<ThrustCurveMotor>, Se
if ( endTime <= time[timeIndex+1] ) {
// we are completely within this time slice so the computation of the average is pretty easy:
double avgImpulse = MathUtil.map(startTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
avgImpulse += MathUtil.map(endTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
avgImpulse /= 2.0;
return avgImpulse;
double startThrust = MathUtil.map(startTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
double endThrust = MathUtil.map(endTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
return (startThrust + endThrust) / 2.0;
}
// portion from startTime through time[timeIndex]
double avgImpulse = 0.0;
// For numeric stability.
if( time[timeIndex+1] - startTime > 0.001 ) {
avgImpulse = (MathUtil.map(startTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]) + thrust[timeIndex+1])
/ 2.0 * (time[timeIndex+1] - startTime);
}
double impulse = 0.0;
// portion from startTime through time[timeIndex+1]
double startThrust = MathUtil.map(startTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
impulse = (time[timeIndex+1] - startTime) * (startThrust + thrust[timeIndex+1]) / 2.0;
// Now add the whole steps;
timeIndex++;
while( timeIndex < time.length -1 && endTime >= time[timeIndex+1] ) {
avgImpulse += (thrust[timeIndex] + thrust[timeIndex+1]) / 2.0 * (time[timeIndex+1]-time[timeIndex]);
while ( timeIndex < time.length -1 && endTime >= time[timeIndex+1] ) {
impulse += (time[timeIndex+1] - time[timeIndex]) * (thrust[timeIndex] + thrust[timeIndex+1]) / 2.0;
timeIndex++;
}
// Now add the bit after the last time index
if ( timeIndex < time.length -1 ) {
double endInstImpulse = MathUtil.map( endTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
avgImpulse += (thrust[timeIndex] + endInstImpulse) / 2.0 * (endTime - time[timeIndex]);
double endThrust = MathUtil.map( endTime, time[timeIndex], time[timeIndex+1], thrust[timeIndex], thrust[timeIndex+1]);
impulse += (endTime - time[timeIndex]) * (thrust[timeIndex] + endThrust) / 2.0;
}
return avgImpulse / (endTime - startTime);
return impulse / (endTime - startTime);
}
@Override