scalismo.sampling.DistributionEvaluator.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
import scalismo.utils.Memoize
/** a probability or density */
trait DistributionEvaluator[A] {
/** log probability/density of sample */
def logValue(sample: A): Double
}
/** gradient evaluator, used together with DistributionEvaluator */
trait GradientEvaluator[A] {
/** gradient at sample */
def gradient(sample: A): A
}
trait MHDistributionEvaluator[A] extends DistributionEvaluator[MHSample[A]] {
/** log probability/density of sample */
def logValue(sample: MHSample[A]): Double
def cached: MHDistributionEvaluator[A] = {
new CachedMHEvaluator[A](this)
}
}
case class CachedMHEvaluator[A](evaluator: MHDistributionEvaluator[A]) extends MHDistributionEvaluator[A] {
val memoizedLogValue = Memoize(evaluator.logValue, 10)
override def logValue(sample: MHSample[A]): Double = {
memoizedLogValue(sample)
}
}