scalismo.sampling.loggers.BestSampleLogger.scala Maven / Gradle / Ivy
/*
* Copyright 2016 University of Basel, Graphics and Vision Research Group
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package scalismo.sampling.loggers
import scalismo.sampling.DistributionEvaluator
/** keep the best sample so far, warning: changes state */
class BestSampleLogger[A](evaluator: DistributionEvaluator[A]) extends ChainStateLogger[A] {
private case class EvaluatedSample(sample: A, value: Double)
private var bestState: Option[EvaluatedSample] = None
override def logState(sample: A): Unit = {
val value = evaluator.logValue(sample)
if (bestState.isEmpty || value > bestState.get.value) {
bestState = Some(EvaluatedSample(sample, value))
}
}
def currentBestSample() = bestState.map(_.sample)
def currentBestValue() = bestState.map(_.value)
}
object BestSampleLogger {
def apply[A](evaluator: DistributionEvaluator[A]) = new BestSampleLogger[A](evaluator)
}