# GOA: Optimization using Grasshopper Optimisation Algorithm In metaheuristicOpt: Metaheuristic for Optimization

## Description

This is the internal function that implements Grasshopper Algorithm. It is used to solve continuous optimization tasks. Users do not need to call it directly, but just use metaOpt.

## Usage

 1 2 GOA(FUN, optimType = "MIN", numVar, numPopulation = 40, maxIter = 500, rangeVar) 

## Arguments

 FUN an objective function or cost function, optimType a string value that represent the type of optimization. There are two option for this arguments: "MIN" and "MAX". The default value is "MIN", which the function will do minimization. Otherwise, you can use "MAX" for maximization problem. The default value is "MIN". numVar a positive integer to determine the number variables. numPopulation a positive integer to determine the number populations. The default value is 40. maxIter a positive integer to determine the maximum number of iterations. The default value is 500. rangeVar a matrix (2 \times n) containing the range of variables, where n is the number of variables, and first and second rows are the lower bound (minimum) and upper bound (maximum) values, respectively. If all variable have equal upper bound, you can define rangeVar as matrix (2 \times 1).

## Details

Grasshopper Optimisation Algorithm (GOA) was proposed by (Mirjalili et al., 2017). The algorithm mathematically models and mimics the behaviour of grasshopper swarms in nature for solving optimisation problems.

## Value

Vector [v1, v2, ..., vn] where n is number variable and vn is value of n-th variable.

## References

Shahrzad Saremi, Seyedali Mirjalili, Andrew Lewis, Grasshopper Optimisation Algorithm: Theory and application, Advances in Engineering Software, Volume 105, March 2017, Pages 30-47, ISSN 0965-9978, https://doi.org/10.1016/j.advengsoft.2017.01.004

metaOpt
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 ################################## ## Optimizing the schewefel's problem 1.2 function # define schewefel's problem 1.2 function as objective function schewefels1.2 <- function(x){ dim <- length(x) result <- 0 for(i in 1:dim){ result <- result + sum(x[1:i])^2 } return(result) } ## Define parameter numVar <- 5 rangeVar <- matrix(c(-10,10), nrow=2) ## calculate the optimum solution using grasshoper algorithm resultGOA <- GOA(schewefels1.2, optimType="MIN", numVar, numPopulation=20, maxIter=100, rangeVar) ## calculate the optimum value using schewefel's problem 1.2 function optimum.value <- schewefels1.2(resultGOA)