/**
* Sends the factor-graph message with and returns the log-normalization constant.
*/
protected function sendMessageVariable(Message $message, Variable $variable)
{
$marginal = $variable->getValue();
$messageValue = $message->getValue();
$logZ = GaussianDistribution::logProductNormalization($marginal, $messageValue);
$variable->setValue(GaussianDistribution::multiply($marginal, $messageValue));
return $logZ;
}
protected function updateMessageVariable(Message $message, Variable $variable)
{
$oldMarginal = clone $variable->getValue();
$oldMessage = $message;
$newMarginal = GaussianDistribution::fromPrecisionMean($oldMarginal->getPrecisionMean() + $this->_newMessage->getPrecisionMean() - $oldMessage->getValue()->getPrecisionMean(), $oldMarginal->getPrecision() + $this->_newMessage->getPrecision() - $oldMessage->getValue()->getPrecision());
$variable->setValue($newMarginal);
$newMessage = $this->_newMessage;
$message->setValue($newMessage);
return GaussianDistribution::subtract($oldMarginal, $newMarginal);
}
private function updateHelper(Message $message1, Message $message2, Variable $variable1, Variable $variable2)
{
$message1Value = clone $message1->getValue();
$message2Value = clone $message2->getValue();
$marginal1 = clone $variable1->getValue();
$marginal2 = clone $variable2->getValue();
$a = $this->_precision / ($this->_precision + $marginal2->getPrecision() - $message2Value->getPrecision());
$newMessage = GaussianDistribution::fromPrecisionMean($a * ($marginal2->getPrecisionMean() - $message2Value->getPrecisionMean()), $a * ($marginal2->getPrecision() - $message2Value->getPrecision()));
$oldMarginalWithoutMessage = GaussianDistribution::divide($marginal1, $message1Value);
$newMarginal = GaussianDistribution::multiply($oldMarginalWithoutMessage, $newMessage);
// Update the message and marginal
$message1->setValue($newMessage);
$variable1->setValue($newMarginal);
// Return the difference in the new marginal
return GaussianDistribution::subtract($newMarginal, $marginal1);
}
protected function updateMessageVariable(Message &$message, Variable &$variable)
{
$oldMarginal = clone $variable->getValue();
$oldMessage = clone $message->getValue();
$messageFromVariable = GaussianDistribution::divide($oldMarginal, $oldMessage);
$c = $messageFromVariable->getPrecision();
$d = $messageFromVariable->getPrecisionMean();
$sqrtC = sqrt($c);
$dOnSqrtC = $d / $sqrtC;
$epsilonTimesSqrtC = $this->_epsilon * $sqrtC;
$d = $messageFromVariable->getPrecisionMean();
$denominator = 1.0 - TruncatedGaussianCorrectionFunctions::wWithinMargin($dOnSqrtC, $epsilonTimesSqrtC);
$newPrecision = $c / $denominator;
$newPrecisionMean = ($d + $sqrtC * TruncatedGaussianCorrectionFunctions::vWithinMargin($dOnSqrtC, $epsilonTimesSqrtC)) / $denominator;
$newMarginal = GaussianDistribution::fromPrecisionMean($newPrecisionMean, $newPrecision);
$newMessage = GaussianDistribution::divide(GaussianDistribution::multiply($oldMessage, $newMarginal), $oldMarginal);
// Update the message and marginal
$message->setValue($newMessage);
$variable->setValue($newMarginal);
// Return the difference in the new marginal
return GaussianDistribution::subtract($newMarginal, $oldMarginal);
}
