diff --git a/R/mutator.polynomial.R b/R/mutator.polynomial.R new file mode 100644 index 0000000..cd477fc --- /dev/null +++ b/R/mutator.polynomial.R @@ -0,0 +1,36 @@ +#' @title +#' Generator of the polynomial mutation operator. +#' +#' @description +#' Performs an polynomial mutation as used in the SMS-EMOA algorithm. +#' +#' @param p [\code{numeric(1)}]\cr +#' Probability of mutation of each gene. +#' @param eta [\code{numeric(1)}\cr +#' Distance parameter of the mutation distribution. +#' @return [\code{ecr_mutator}] +#' @family mutators +#' @export +makePolynomialMutation = function(p = 0.2, eta = 10) { + assertNumber(p, lower = 0, upper = 1, na.ok = FALSE) + assertNumber(eta, lower = 1, finite = TRUE, na.ok = FALSE) + + force(p) + force(eta) + + mutator = function(ind, task, control) { + par.set = task$par.set + lower = getLower(par.set) + upper = getUpper(par.set) + child = .Call("polynomialMutationC", ind, lower, upper, p, eta) + return(child) + } + + makeMutator( + mutator = mutator, + name = "Polynomial mutation operator", + description = "Apply polynomial mutation to an individual.", + supported = "float", + params = list(p = p, eta = eta) + ) +} diff --git a/man/makePolynomialMutation.Rd b/man/makePolynomialMutation.Rd new file mode 100644 index 0000000..b132fd8 --- /dev/null +++ b/man/makePolynomialMutation.Rd @@ -0,0 +1,30 @@ +% Generated by roxygen2: do not edit by hand +% Please edit documentation in R/mutator.polynomial.R +\name{makePolynomialMutation} +\alias{makePolynomialMutation} +\title{Generator of the polynomial mutation operator.} +\usage{ +makePolynomialMutation(p = 0.2, eta = 10) +} +\arguments{ +\item{p}{[\code{numeric(1)}]\cr +Probability of mutation of each gene.} + +\item{eta}{[\code{numeric(1)}\cr +Distance parameter of the mutation distribution.} +} +\value{ +[\code{ecr_mutator}] +} +\description{ +Performs an polynomial mutation as used in the SMS-EMOA algorithm. +} +\seealso{ +Other mutators: \code{\link{makeBitFlipMutator}}, + \code{\link{makeGaussMutator}}, + \code{\link{makeInsertionMutator}}, + \code{\link{makeScrambleMutator}}, + \code{\link{makeSwapMutator}}, + \code{\link{makeUniformMutator}} +} + diff --git a/src/polynomialMutation.c b/src/polynomialMutation.c new file mode 100644 index 0000000..a4d9c29 --- /dev/null +++ b/src/polynomialMutation.c @@ -0,0 +1,61 @@ +#include +#include + +#include "macros.h" +#include "helpers.h" + +/* Polynomial mutation operator. + * + * Performs polynomial mutation of an individual with probability p for each gene. + * + * @param x [numeric] + * Individual. + * @param lower [numeric] + * Lower box constraints. + * @param upper [numeric] + * Upper box constraints. + * @param p [numeric(1)] + * Probability for mutation of each gene. + * @param eta [numeric(1)] + * Parameter eta. + * @return [numeric] Mutated individual. + */ +SEXP polynomialMutationC(SEXP x, SEXP lower, SEXP upper, SEXP p, SEXP eta) { + SEXP res; + + // unpack imcoming R data + EXTRACT_NUMERIC_VECTOR(x, c_x, d); + EXTRACT_NUMERIC_VECTOR(lower, c_lower, c_lower_length); + EXTRACT_NUMERIC_VECTOR(upper, c_upper, c_upper_length); + EXTRACT_REAL(p, c_p); + EXTRACT_REAL(eta, c_eta); + + const double mpow = 1.0 / (c_eta + 1.0); + + PROTECT(res = allocVector(REALSXP, d)); + double *c_res = REAL(res); + + GetRNGstate(); + double rnd, deltaq; + for (int i = 0; i < d; ++i) { + // do all the complicated stuff here + if (unif_rand() < c_p) { + const double delta = c_upper[i] - c_lower[i]; + rnd = unif_rand(); + if (rnd <= 0.5) { + const double xy = 1.0 - (c_x[i] - c_lower[i]) / delta; + deltaq = pow(2.0 * rnd + (1.0 - 2.0 * rnd) * pow(xy, c_eta + 1.0), mpow) - 1.0; + } else { + const double xy = 1.0 - (c_upper[i] - c_x[i]) / delta; + deltaq = 1.0 - pow(2.0 * (1.0 - rnd) + 2.0 * (rnd - 0.5) * pow(xy, c_eta + 1.0), mpow); + } + c_res[i] = forceToBounds(c_x[i] + deltaq * delta, c_lower[i], c_upper[i]); + } else { + c_res[i] = c_x[i]; + } + } + + PutRNGstate(); + UNPROTECT(1); /* res */ + return(res); +}