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Separate setting explicit engine for linear equation system solution method. 

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@4649 bbc10eb1-c90d-0410-af57-cb519fbb1720
master
Dave Parker 14 years ago
parent
a51157e11a
commit
1e0dff70d2
2 changed files with 87 additions and 20 deletions
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  1. 31
      prism/src/explicit/DTMCModelChecker.java
  2. 76
      prism/src/explicit/ProbModelChecker.java

31
prism/src/explicit/DTMCModelChecker.java
View File

@ -291,12 +291,15 @@ public class DTMCModelChecker extends ProbModelChecker
BitSet no, yes;
int i, n, numYes, numNo;
long timer, timerProb0, timerProb1;
// Local copy of setting
LinEqMethod linEqMethod = this.linEqMethod;
// Check for some unsupported combinations
if (solnMethod == SolnMethod.VALUE_ITERATION && valIterDir == ValIterDir.ABOVE && !(precomp && prob0)) {
throw new PrismException("Precomputation (Prob0) must be enabled for value iteration from above");
// Switch to a supported method, if necessary
if (!(linEqMethod == LinEqMethod.POWER || linEqMethod == LinEqMethod.GAUSS_SEIDEL)) {
linEqMethod = LinEqMethod.GAUSS_SEIDEL;
mainLog.printWarning("Switching to linear equation solution method \"" + linEqMethod.fullName() + "\"");
}
// Start probabilistic reachability
timer = System.currentTimeMillis();
mainLog.println("Starting probabilistic reachability...");
@ -338,15 +341,15 @@ public class DTMCModelChecker extends ProbModelChecker
mainLog.println("target=" + target.cardinality() + ", yes=" + numYes + ", no=" + numNo + ", maybe=" + (n - (numYes + numNo)));
// Compute probabilities
switch (solnMethod) {
case VALUE_ITERATION:
switch (linEqMethod) {
case POWER:
res = computeReachProbsValIter(dtmc, no, yes, init, known);
break;
case GAUSS_SEIDEL:
res = computeReachProbsGaussSeidel(dtmc, no, yes, init, known);
break;
default:
throw new PrismException("Unknown DTMC solution method " + solnMethod);
throw new PrismException("Unknown linear equation solution method " + linEqMethod.fullName());
}
// Finished probabilistic reachability
@ -808,6 +811,14 @@ public class DTMCModelChecker extends ProbModelChecker
BitSet inf;
int i, n, numTarget, numInf;
long timer, timerProb1;
// Local copy of setting
LinEqMethod linEqMethod = this.linEqMethod;
// Switch to a supported method, if necessary
if (!(linEqMethod == LinEqMethod.POWER)) {
linEqMethod = LinEqMethod.POWER;
mainLog.printWarning("Switching to linear equation solution method \"" + linEqMethod.fullName() + "\"");
}
// Start expected reachability
timer = System.currentTimeMillis();
@ -840,12 +851,12 @@ public class DTMCModelChecker extends ProbModelChecker
mainLog.println("target=" + numTarget + ", inf=" + numInf + ", rest=" + (n - (numTarget + numInf)));
// Compute rewards
switch (solnMethod) {
case VALUE_ITERATION:
switch (linEqMethod) {
case POWER:
res = computeReachRewardsValIter(dtmc, mcRewards, target, inf, init, known);
break;
default:
throw new PrismException("Unknown DTMC solution method " + solnMethod);
throw new PrismException("Unknown linear equation solution method " + linEqMethod.fullName());
}
// Finished expected reachability

76
prism/src/explicit/ProbModelChecker.java
View File

@ -47,6 +47,8 @@ public class ProbModelChecker extends StateModelChecker
{
// Flags/settings
// Method used to solve linear equation systems
protected LinEqMethod linEqMethod = LinEqMethod.GAUSS_SEIDEL;
// Iterative numerical method termination criteria
protected TermCrit termCrit = TermCrit.RELATIVE;
// Parameter for iterative numerical method termination criteria
@ -67,6 +69,32 @@ public class ProbModelChecker extends StateModelChecker
// Enums for flags/settings
// Method used for numerical solution
public enum LinEqMethod {
POWER, JACOBI, GAUSS_SEIDEL, BACKWARDS_GAUSS_SEIDEL, JOR, SOR, BACKWARDS_SOR;
public String fullName()
{
switch (this) {
case POWER:
return "Power method";
case JACOBI:
return "Jacobi";
case GAUSS_SEIDEL:
return "Gauss-Seidel";
case BACKWARDS_GAUSS_SEIDEL:
return "Backwards Gauss-Seidel";
case JOR:
return "JOR";
case SOR:
return "SOR";
case BACKWARDS_SOR:
return "Backwards SOR";
default:
return this.toString();
}
}
};
// Iterative numerical method termination criteria
public enum TermCrit {
ABSOLUTE, RELATIVE
@ -83,13 +111,33 @@ public class ProbModelChecker extends StateModelChecker
};
// Settings methods
/**
* Set settings from a PRISMSettings object.
*/
public void setSettings(PrismSettings settings)
public void setSettings(PrismSettings settings) throws PrismException
{
String s;
// PRISM_LIN_EQ_METHOD
s = settings.getString(PrismSettings.PRISM_LIN_EQ_METHOD);
if (s.equals("Power")) {
setLinEqMethod(LinEqMethod.POWER);
} else if (s.equals("Jacobi")) {
setLinEqMethod(LinEqMethod.JACOBI);
} else if (s.equals("Gauss-Seidel")) {
setLinEqMethod(LinEqMethod.GAUSS_SEIDEL);
} else if (s.equals("Backwards Gauss-Seidel")) {
setLinEqMethod(LinEqMethod.BACKWARDS_GAUSS_SEIDEL);
} else if (s.equals("JOR")) {
setLinEqMethod(LinEqMethod.JOR);
} else if (s.equals("SOR")) {
setLinEqMethod(LinEqMethod.SOR);
} else if (s.equals("Backwards SOR")) {
setLinEqMethod(LinEqMethod.BACKWARDS_SOR);
} else {
throw new PrismException("Explicit engine does not support linear equation solution method \"" + s + "\"");
}
s = settings.getString(PrismSettings.PRISM_TERM_CRIT);
if (s.equals("Absolute")) {
setTermCrit(TermCrit.ABSOLUTE);
@ -102,12 +150,6 @@ public class ProbModelChecker extends StateModelChecker
setProb0(settings.getBoolean(PrismSettings.PRISM_PROB0));
setProb1(settings.getBoolean(PrismSettings.PRISM_PROB1));
// valiterdir
s = settings.getString(PrismSettings.PRISM_LIN_EQ_METHOD);
if (s.equals("Gauss-Seidel")) {
setSolnMethod(SolnMethod.GAUSS_SEIDEL);
} else {
setSolnMethod(SolnMethod.VALUE_ITERATION);
}
s = settings.getString(PrismSettings.PRISM_MDP_SOLN_METHOD);
if (s.equals("Gauss-Seidel")) {
setSolnMethod(SolnMethod.GAUSS_SEIDEL);
@ -146,6 +188,7 @@ public class ProbModelChecker extends StateModelChecker
public void printSettings()
{
super.printSettings();
mainLog.print("linEqMethod = " + linEqMethod + " ");
mainLog.print("termCrit = " + termCrit + " ");
mainLog.print("termCritParam = " + termCritParam + " ");
mainLog.print("maxIters = " + maxIters + " ");
@ -166,6 +209,14 @@ public class ProbModelChecker extends StateModelChecker
this.verbosity = verbosity;
}
/**
* Set method used to solve linear equation systems.
*/
public void setLinEqMethod(LinEqMethod linEqMethod)
{
this.linEqMethod = linEqMethod;
}
/**
* Set termination criteria type for numerical iterative methods.
*/
@ -237,6 +288,11 @@ public class ProbModelChecker extends StateModelChecker
return verbosity;
}
public LinEqMethod getLinEqMethod()
{
return linEqMethod;
}
public TermCrit getTermCrit()
{
return termCrit;
@ -377,7 +433,7 @@ public class ProbModelChecker extends StateModelChecker
return StateValues.createFromBitSet(sol, model);
}
}
/**
* Model check an R operator expression and return the values for all states.
*/
@ -448,7 +504,7 @@ public class ProbModelChecker extends StateModelChecker
default:
throw new PrismException("Cannot build rewards for " + modelType + "s");
}
// Compute rewards
mainLog.println("Building reward structure...");
switch (modelType) {

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