|
|
||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object net.algart.model3d.common.movement.model.AbstractMovementIntegrator
public abstract class AbstractMovementIntegrator extends java.lang.Object implements MovementIntegrator
A skeletal implementation of the MovementIntegrator
interface to minimize
the effort required to implement this interface.
All non-abstract methods of this class, excepting performIteration()
,
are completely implemented and usually should not be overridden.
Also this class offers protected methods
calculateLeftSide(double[], double[], double[], double[], double[], double[], double)
,calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
preprocess()
,simplifying implementation of performIteration()
method.
This class, by default, does not support estimation of the maximal and mean errors:
isErrorInformationAvailable()
method returns false,
maxLastCoordinateError()
, meanLastCoordinateError()
,
maxLastVelocityError()
, meanLastVelocityError()
methods return Double.NaN.
But inheritors of this class can add this feature but overriding these methods.
AlgART Laboratory 2010
Modifier and Type | Field and Description |
---|---|
protected java.util.concurrent.atomic.AtomicLong |
countOfCheckedNeighbours
The counter, returned by getCounterOfCheckedNeighbours() method. |
protected java.util.concurrent.atomic.AtomicLong |
countOfProcessedInteractions
The counter, returned by getCounterOfProcessedInteractions() method. |
protected java.util.concurrent.atomic.AtomicLong |
countOfProcessedItems
The counter, returned by getCounterOfProcessedItems() method. |
protected java.util.concurrent.atomic.AtomicLong |
countOfProcessedSymmetricInteractions
The counter, returned by getCounterOfProcessedSymmetricInteractions() method. |
protected int |
n
The current size of itemSet , calculated while the last
call of preprocess() method. |
Modifier | Constructor and Description |
---|---|
protected |
AbstractMovementIntegrator(ItemSet itemSet,
java.util.Collection<InteractionRule> interactionRules,
double deltaT)
Creates new instance of this class. |
Modifier and Type | Method and Description |
---|---|
protected void |
calculateLeftSide(double[] resultDX,
double[] resultDY,
double[] resultDZ,
double[] resultDVX,
double[] resultDVY,
double[] resultDVZ,
double deltaT)
Calculates the left sides of the motion equations, integrated by this object, multiplied by the passed deltaT=Δt argument. |
protected void |
calculateLeftSide(double[] resultDX,
double[] resultDY,
double[] resultDZ,
double[] resultDVX,
double[] resultDVY,
double[] resultDVZ,
double deltaT,
int threadIndex,
int fromIndex,
int toIndex)
An analog of the full calculateLeftSide(double[], double[], double[], double[], double[], double[], double) method,
which processes only the specified range of items. |
void |
copyBasicSettings(MovementIntegrator source)
Copies all basic settings, that can be accessed via getXxx/setXxx methods of this interface, from the specified object. |
double |
getAccelerationLimit()
Returns the acceleration limit Amax. |
long |
getCounterOfCheckedNeighbours()
Returns the internal thread-safe counter of "neighbour" item pairs ,
which were checked by MovementIntegrator.performIteration() method
while calculation of the right side of the motion equations. |
long |
getCounterOfProcessedInteractions()
Returns the internal thread-safe counter of really interacted item pairs, which were really processed by MovementIntegrator.performIteration() method
while calculation of the right side of the motion equations,
that is for which calculateForce method was really called
and returned true. |
long |
getCounterOfProcessedItems()
Returns the internal thread-safe counter of items, which were processed by MovementIntegrator.performIteration() method
while calculation of the right side of the motion equations. |
long |
getCounterOfProcessedSymmetricInteractions()
An analog of the counter MovementIntegrator.getCounterOfProcessedInteractions() , counting only pairs,
which were processed in more efficient way thanks to
symmetric interaction rules . |
double |
getDeltaT()
Returns the time step Δt for one iteration of integration. |
java.util.List<InteractionRule> |
getInteractionRules()
Returns the list of interaction rules, used by this object. |
ItemSet |
getItemSet()
Returns the item set, processed by this object. |
int |
getNumberOfParallelTasks()
Returns the current number of parallel threads, which is recommended this object to use for optimizing calculations on multiprocessor systems. |
double |
getT()
Returns the current time t in the physical model. |
double |
getVelocityLimit()
Returns the velocity limit Vmax. |
boolean |
getViscousForces()
Returns true if this object works in the mode of viscous forces. |
boolean |
isErrorInformationAvailable()
Returns true if this implementation allows to estimate the maximal and mean error of calculating coordinates and velocities. |
double |
maxLastCoordinateError()
Returns the estimation of the maximal error of calculating coordinates while the previous MovementIntegrator.performIteration() call, if this implementation
supports this feature,
or Double.NaN in other case. |
double |
maxLastVelocityError()
Returns the estimation of the maximal error of calculating velocities while the previous MovementIntegrator.performIteration() call, if this implementation
supports this feature,
or Double.NaN in other case. |
double |
meanLastCoordinateError()
Returns the estimation of the average error of calculating coordinates while the previous MovementIntegrator.performIteration() call, if this implementation
supports this feature,
or Double.NaN in other case. |
double |
meanLastVelocityError()
Returns the estimation of the average error of calculating velocities while the previous MovementIntegrator.performIteration() call, if this implementation
supports this feature,
or Double.NaN in other case. |
abstract void |
performIteration()
Performs one iteration of integration. |
protected void |
preprocess()
Performs necessary preprocessing before an iteration, in particular, reallocate all necessary work memory. |
void |
resetCounters()
Resets to 0 all internal counters, returned by MovementIntegrator.getCounterOfProcessedItems() ,
MovementIntegrator.getCounterOfCheckedNeighbours() , MovementIntegrator.getCounterOfProcessedInteractions()
and MovementIntegrator.getCounterOfProcessedSymmetricInteractions() methods. |
void |
setAccelerationLimit(double accelerationLimit)
Sets the acceleration limit Amax to the given value. |
void |
setDeltaT(double deltaT)
Sets the current time Δt for one iteration of integration. |
void |
setNumberOfParallelTasks(int numberOfParallelTasks)
Sets the number of parallel threads, which should be used, if possible, for optimizing calculations on multiprocessor systems. |
void |
setT(double t)
Sets the current time t in the physical model. |
void |
setVelocityLimit(double velocityLimit)
Sets the velocity limit Vmax to the given value. |
void |
setViscousForces(boolean viscousForces)
Sets the mode of viscous forces ("pseudo-Newton's" motion equations), if the argument is true, or the usual mode (standard Newton's laws), if the argument is false See comments to this interface for more details. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
protected final java.util.concurrent.atomic.AtomicLong countOfProcessedItems
getCounterOfProcessedItems()
method.
This counter is increased by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method.
protected final java.util.concurrent.atomic.AtomicLong countOfCheckedNeighbours
getCounterOfCheckedNeighbours()
method.
This counter is increased by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method.
protected final java.util.concurrent.atomic.AtomicLong countOfProcessedInteractions
getCounterOfProcessedInteractions()
method.
This counter is increased by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method.
protected final java.util.concurrent.atomic.AtomicLong countOfProcessedSymmetricInteractions
getCounterOfProcessedSymmetricInteractions()
method.
This counter is increased by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method.
protected int n
size
of itemSet
, calculated while the last
call of preprocess()
method.
After creating the object, this field contains 0.
Constructor Detail |
---|
protected AbstractMovementIntegrator(ItemSet itemSet, java.util.Collection<InteractionRule> interactionRules, double deltaT)
The itemSet argument is just stored in an internal field, and this reference
will be returned by getItemSet()
method.
Unlike this, the interactionRules collection is copied into a newly created list:
no references to it are maintained by the created object.
itemSet
- the item set, which will be processed by this class.interactionRules
- the list of interaction rules, used by this class.deltaT
- the time step Δt.java.lang.NullPointerException
- if one of the arguments is null or
if one of interaction rules in the passed collection is null.java.lang.IllegalArgumentException
- if deltaT<0.Method Detail |
---|
public ItemSet getItemSet()
MovementIntegrator
ItemSet
interface.
getItemSet
in interface MovementIntegrator
ItemSet
object, processed by this object.public java.util.List<InteractionRule> getInteractionRules()
MovementIntegrator
The result is an immutable view (Collections.unmodifiableList) or a clone of the internal collection, stored by this object: you cannot modify the set of used interaction rules via the result of this method.
The elements of the returned list are never null.
getInteractionRules
in interface MovementIntegrator
public int getNumberOfParallelTasks()
MovementIntegrator
The returned value is always positive (>0).
getNumberOfParallelTasks
in interface MovementIntegrator
public void setNumberOfParallelTasks(int numberOfParallelTasks)
MovementIntegrator
If this argument is 0, it is automatically replaced with
MovementIntegrator.getNumberOfParallelTasks()
method will return not 0,
but the actual number of available processors.
setNumberOfParallelTasks
in interface MovementIntegrator
numberOfParallelTasks
- the desired number of parallel threads for multiprocessor optimization.public boolean getViscousForces()
MovementIntegrator
comments to this interface
for more details.
getViscousForces
in interface MovementIntegrator
public void setViscousForces(boolean viscousForces)
MovementIntegrator
comments to this interface
for more details.
setViscousForces
in interface MovementIntegrator
viscousForces
- whether you this object should be switched in the mode of viscous forces.public double getAccelerationLimit()
MovementIntegrator
comments to this interface
for more details.
getAccelerationLimit
in interface MovementIntegrator
public void setAccelerationLimit(double accelerationLimit)
MovementIntegrator
comments to this interface
for more details.
setAccelerationLimit
in interface MovementIntegrator
accelerationLimit
- new acceleration limit Amax.public double getVelocityLimit()
MovementIntegrator
comments to this interface
for more details.
getVelocityLimit
in interface MovementIntegrator
public void setVelocityLimit(double velocityLimit)
MovementIntegrator
comments to this interface
for more details.
setVelocityLimit
in interface MovementIntegrator
velocityLimit
- new velocity limit Vmax.public double getT()
MovementIntegrator
MovementIntegrator.performIteration()
method.
getT
in interface MovementIntegrator
MovementIntegrator.getDeltaT()
public void setT(double t)
MovementIntegrator
setT
in interface MovementIntegrator
t
- new value of the current time t.public double getDeltaT()
MovementIntegrator
getDeltaT
in interface MovementIntegrator
public void setDeltaT(double deltaT)
MovementIntegrator
setDeltaT
in interface MovementIntegrator
deltaT
- new value of the time step Δt.public void copyBasicSettings(MovementIntegrator source)
MovementIntegrator
setNumberOfParallelTasks
(source.getNumberOfParallelTasks()
);setViscousForces
(source.getViscousForces()
);setAccelerationLimit
(source.getAccelerationLimit()
);setVelocityLimit
(source.getVelocityLimit()
);setT
(source.getT()
);setDeltaT
(source.getDeltaT()
);
copyBasicSettings
in interface MovementIntegrator
source
- another movement integrator, the basic settings of which should be copied into this one.public long getCounterOfProcessedItems()
MovementIntegrator
MovementIntegrator.performIteration()
method
while calculation of the right side of the motion equations.
Note that MovementIntegrator.performIteration()
can calculate the right side of the equations several times
(as in Runge-Kutta algorithms), and then every item will be also counted several times.
Usually the items, which do not have coordinates of centers and velocities
or do not have masses
, are not counted.
This counter is 0 after creating new instance of this class
and can be set to 0 by MovementIntegrator.resetCounters()
method.
This method is provided for profiling and debugging needs only. It works as described above in the implementations, offered by this package, but there is no guarantee that it will return correct values in all implementations. If the implementation does not provide this counter, this method should return 0 always.
getCounterOfProcessedItems
in interface MovementIntegrator
public long getCounterOfCheckedNeighbours()
MovementIntegrator
"neighbour" item pairs
,
which were checked by MovementIntegrator.performIteration()
method
while calculation of the right side of the motion equations.
This number depends on the implementation of ItemSet
interface:
good implementations, like GridItemSet
, allow to check only restricted number of items
while finding all "neighbours" of the given item, which can interact with it.
Note that the "neighbour" pair is counted independently for both its elements. In other words, it two items act to each other, their pair is counter twice.
Note that MovementIntegrator.performIteration()
can calculate the right side of the equations several times
(as in Runge-Kutta algorithms), and then every neighbour item pair will be also counted several times.
This counter is 0 after creating new instance of this class
and can be set to 0 by MovementIntegrator.resetCounters()
method.
This method is provided for profiling and debugging needs only. It works as described above in the implementations, offered by this package, but there is no guarantee that it will return correct values in all implementations. If the implementation does not provide this counter, this method should return 0 always.
getCounterOfCheckedNeighbours
in interface MovementIntegrator
public long getCounterOfProcessedInteractions()
MovementIntegrator
MovementIntegrator.performIteration()
method
while calculation of the right side of the motion equations,
that is for which calculateForce
method was really called
and returned true.
Note that an interacted pair is counted independently for both items. In other words, it two items act to each other, their pair is counter twice.
Note that an interacted pair is counted again for every interaction rule, applicable for this pair.
So, if there are K>1 rules, in which calculateForce
method
returned true for the given pair, then this pair will be counted K times.
Note that MovementIntegrator.performIteration()
can calculate the right side of the equations several times
(as in Runge-Kutta algorithms), and then every neighbour item pair will be also counted several times.
This counter is 0 after creating new instance of this class
and can be set to 0 by MovementIntegrator.resetCounters()
method.
This method is provided for profiling and debugging needs only. It works as described above in the implementations, offered by this package, but there is no guarantee that it will return correct values in all implementations. If the implementation does not provide this counter, this method should return 0 always.
getCounterOfProcessedInteractions
in interface MovementIntegrator
public long getCounterOfProcessedSymmetricInteractions()
MovementIntegrator
MovementIntegrator.getCounterOfProcessedInteractions()
, counting only pairs,
which were processed in more efficient way thanks to
symmetric interaction rules
.
Namely, some implementations of this interface can use the fact, that some interaction is symmetric
(implements SymmetricInteractionRule
), and calculate the interaction force only once.
The force F' of acting of the 2nd item to the 1st one is produced from
the force F of acting of the 1st item to the 2nd one by changing the sign:
MovementIntegrator.getCounterOfProcessedInteractions()
method.
But some "neighbour" item pairs cannot be processed in such a manner, for example,
when the first item is processed (moved) by one processor in multiprocessor system
and the second one is processed by another processor.
In such situation, this counter is not increased, though the counter,
returned by MovementIntegrator.getCounterOfProcessedInteractions()
method, is increased by 2
(by 1 for each from two items). So, this method can help to measure optimization,
achieved thanks to usage of symmetric interaction rules
.
This counter is 0 after creating new instance of this class
and can be set to 0 by MovementIntegrator.resetCounters()
method.
This method is provided for profiling and debugging needs only. It works as described above in the implementations, offered by this package, but there is no guarantee that it will return correct values in all implementations. If the implementation does not provide this counter, this method should return 0 always.
getCounterOfProcessedSymmetricInteractions
in interface MovementIntegrator
symmetric interaction rules
.public void resetCounters()
MovementIntegrator
MovementIntegrator.getCounterOfProcessedItems()
,
MovementIntegrator.getCounterOfCheckedNeighbours()
, MovementIntegrator.getCounterOfProcessedInteractions()
and MovementIntegrator.getCounterOfProcessedSymmetricInteractions()
methods.
resetCounters
in interface MovementIntegrator
public abstract void performIteration()
MovementIntegrator
having centers and velocities
and having masses
,
according to the motion equations.
See comments to this interface
for more details.
performIteration
in interface MovementIntegrator
public boolean isErrorInformationAvailable()
MovementIntegrator
MovementIntegrator.maxLastCoordinateError()
, MovementIntegrator.meanLastCoordinateError()
,
MovementIntegrator.maxLastVelocityError()
, MovementIntegrator.meanLastVelocityError()
methods after
every MovementIntegrator.performIteration()
call to get this information.
In other case, those methods return Double.NaN.
isErrorInformationAvailable
in interface MovementIntegrator
public double maxLastCoordinateError()
MovementIntegrator
MovementIntegrator.performIteration()
call, if this implementation
supports
this feature,
or Double.NaN in other case.
maxLastCoordinateError
in interface MovementIntegrator
public double maxLastVelocityError()
MovementIntegrator
MovementIntegrator.performIteration()
call, if this implementation
supports
this feature,
or Double.NaN in other case.
maxLastVelocityError
in interface MovementIntegrator
public double meanLastCoordinateError()
MovementIntegrator
MovementIntegrator.performIteration()
call, if this implementation
supports
this feature,
or Double.NaN in other case.
meanLastCoordinateError
in interface MovementIntegrator
public double meanLastVelocityError()
MovementIntegrator
MovementIntegrator.performIteration()
call, if this implementation
supports
this feature,
or Double.NaN in other case.
meanLastVelocityError
in interface MovementIntegrator
protected void calculateLeftSide(double[] resultDX, double[] resultDY, double[] resultDZ, double[] resultDVX, double[] resultDVY, double[] resultDVZ, double deltaT)
Δt dw/dt = Δt f(t, w)
— see the concrete equation sets in comments to MovementIntegrator
interface.
The left sides of the equations (multiplied by Δt) are stored in the passed Java arrays resultDX, resultDY, resultDZ, resultDVX, resultDVY, resultDVZ: the element #k of these arrays will contain, correspondingly, the values
Δt * dxk/dt,
Δt * dyk/dt,
Δt * dzk/dt,
Δt * dvxk/dt,
Δt * dvyk/dt,
Δt * dvzk/dt.
— the derivatives of coordinates and velocity components for the item
itemSet.get
(k).
If the item #k does not implement both HavingVelocity
and HavingMass
interface,
the corresponding elements of the passed array are filled by zero (0.0).
This method uses multithreading for optimizing calculations on multiprocessor system,
it the desired number of parallel task is set to a value m >1 by
setNumberOfParallelTasks(int)
method. Namely, this method
splits the item set into m ranges and calculates the derivatives for them
in m parallel threads. Each range (or all item set in a case m=1)
is processed by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method, which really performs all necessary calculations.
Note: this method does not use the current Δt, returned by getDeltaT()
method,
but uses the deltaT argument instead.
Note: this method uses some work memory, which must be allocated and correctly initialized by
preprocess()
method before calling this method. After preprocess()
call,
the item set should not be changed in any way, in other case this method will work incorrectly
and even can throw an exception.
resultDX
- array for storing dxk/dt * Δt values.resultDY
- array for storing dyk/dt * Δt values.resultDZ
- array for storing dzk/dt * Δt values.resultDVX
- array for storing dvxk/dt * Δt values.resultDVY
- array for storing dvyk/dt * Δt values.resultDVZ
- array for storing dvzk/dt * Δt values.deltaT
- Δt value.java.lang.NullPointerException
- if one of passed arrays is null.java.lang.IllegalArgumentException
- if deltaT argument is negative (< 0.0).protected void calculateLeftSide(double[] resultDX, double[] resultDY, double[] resultDZ, double[] resultDVX, double[] resultDVY, double[] resultDVZ, double deltaT, int threadIndex, int fromIndex, int toIndex)
calculateLeftSide(double[], double[], double[], double[], double[], double[], double)
method,
which processes only the specified range of items.
The range is specified by fromIndex and toIndex argument:
if fills only the elements of resultDX, resultDY, resultDZ,
resultDVX, resultDVY, resultDVZ arrays with indexes
fromIndex<=k<toIndex.
The argument threadIndex, from 0 to getNumberOfParallelTasks()
-1,
specifies the index of the thread, which is executing this method,
and is used for choosing a separate work memory for every thread while parallel execution.
While single-thread execution, this argument should be 0.
This method is usually called from
calculateLeftSide(double[], double[], double[], double[], double[], double[], double)
method only.
resultDX
- array for storing dxk/dt * Δt values.resultDY
- array for storing dyk/dt * Δt values.resultDZ
- array for storing dzk/dt * Δt values.resultDVX
- array for storing dvxk/dt * Δt values.resultDVY
- array for storing dvyk/dt * Δt values.resultDVZ
- array for storing dvzk/dt * Δt values.deltaT
- Δt value.threadIndex
- the index of thread, which calls this method.fromIndex
- start index of processed items, inclusive.toIndex
- end index of processed items, exclusive.java.lang.NullPointerException
- if one of passed arrays is null.java.lang.IllegalArgumentException
- if deltaT argument is negative (< 0.0).java.lang.IndexOutOfBoundsException
- for illegal fromIndex and toIndex
(fromIndex < 0 || toIndex > n
|| fromIndex > toIndex),
or if threadIndex is out of
0..getNumberOfParallelTasks()
-1 range.protected void preprocess()
performIteration()
method
and before any call of
calculateLeftSide(double[], double[], double[], double[], double[], double[], double)
or
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
methods, if the item set was corrected in any way after the last call of this method.
This implementation reallocates a temporary memory, used by
calculateLeftSide(double[], double[], double[], double[], double[], double[], double, int, int, int)
method, and calls itemSet.preprocess()
.
Please don't forget to call it from all overriding implementations.
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |