'test\_functions': new test function 'sschwefel1\_2'

NAMESPACE

@@ -42,20 +42,21 @@ export(hydroPSO,
        read_results,
        verification,
        wquantile,
-       sphere,
-       rosenbrock,
+       ackley,
+       griewank,
        rastrigrin, # wrong name, only used for backward compatibility
        rastrigin,
-       griewank,
+       rosenbrock,
        schafferF6,
-       ackley,
-       ssphere,
-       srosenbrock,       
-       srastrigin,
+       schwefel
+       sphere,
+       sackley,
        sgriewank,
+       srastrigin,
        #schafferF6,
-       sackley,
-       sschwefel
+       srosenbrock,       
+       sschwefel1_2,
+       ssphere       
       )
       
 S3method(params2ecdf, matrix)

NEWS

@@ -55,12 +55,13 @@ NEWS/ChangeLog for hydroPSO
                             -) boundary.wall: 'reflecting' in  hydroPSO ver <= 0.1-58 is not longer equivalent to 'reflecting' in  hydroPSO ver >= 0.1-58
 
         o 'test_functions': -) new benchmark functions: 
-                               'ssphere'    : shifted Sphere (CEC 2005), 
-                               'srosenbrock': shifted Rosenbrock (CEC 2005), 
-                               'srastrigin' : shifted Rastrigin (CEC 2005),  
-                               'sgriewank'  : shifted Griewank (CEC 2005),  
-                               'sackley'    : shifted Ackley (CEC 2005),   
-                               'sschwefel'  : shifted Schwefel's Problem 1.2 (CEC 2005)       
+                               'schwefel'    : Schwefel function
+                               'ssphere'     : shifted Sphere (CEC 2005), 
+                               'srosenbrock' : shifted Rosenbrock (CEC 2005), 
+                               'srastrigin'  : shifted Rastrigin (CEC 2005),  
+                               'sgriewank'   : shifted Griewank (CEC 2005),  
+                               'sackley'     : shifted Ackley (CEC 2005),   
+                               'sschwefel1_2': shifted Schwefel's Problem 1.2 (CEC 2005)       
         
 0.1-58	14-Sep-2012
         o 'hydroPSO'      : -) 'random.update' is now ONLY used when 'best.update="async". In hydroPSO 0.1-57 'random.update' was set to TRUE 

R/test_functions.R

@@ -67,6 +67,18 @@ ackley <- function(x) {
 } # 'schafferF6' END
 
 
+# MZB, 25-Sep-2012. Schwefel: f(xi,..,xi)=0, with xi= 420.968746
+# Minimization. In [-500, 500]^n. AcceptableError < 
+# Properties: Multimodal, Additively separable 
+#             This function is deceptive in that the global minimum is geometrically 
+#             distant, over the parameter space, from the next best local minima. 
+# Ref: http://www.scribd.com/doc/74351406/7/Schwefel%E2%80%99s-function
+schwefel <- function(x) { 
+  n <- length(x) 
+  return( 418.98288727433799*n + sum( -x*sin( sqrt(abs(x)) ) ) )
+} # 'schwefel' END
+
+
 ################################################################################
 ########################### Shifted Functions ##################################
 ################################################################################
@@ -127,12 +139,12 @@ srastrigin <- function(x, o=-5+10*runif(length(x)), fbias=-330) {
 # MZB, 25-Sep-2012. Shifted Schwefel's Problem 1.2 (CEC 2005): f(o,..,o)=-450. 
 # Minimization. In [-100, 100]^n. AcceptableError < 100
 # Properties: Unimodal, Shifted, Non-separable, Scalable
-sschwefel <- function(x, o=-100+200*runif(length(x)), fbias=-450) { 
+sschwefel1_2 <- function(x, o=-100+200*runif(length(x)), fbias=-450) { 
   n <- length(x) 
   if (n != length(o)) stop("length(x) != length(o)")
   z <- x - o
   return( sum( (cumsum(z))^2 ) + fbias )
-} # 'srastrigin' END
+} # 'sschwefel1_2' END
 
 
 #### TODO: find the definition of the rotation matrix M:

man/test_functions.Rd

@@ -10,12 +10,13 @@
 \alias{rastrigin}
 \alias{rosenbrock}
 \alias{schafferF6}
+\alias{schwefel}
 \alias{sphere}
 \alias{sackley}
 \alias{sgriewank}
 \alias{srastrigin}
 \alias{srosenbrock}
-\alias{sschwefel}
+\alias{sschwefel1_2}
 \alias{ssphere}
 
 %- Also NEED an '\alias' for EACH other topic documented here.
@@ -31,12 +32,13 @@ griewank(x)
 rastrigrin(x)
 rosenbrock(x)
 schafferF6(x)
+schwefel(x)
 sphere(x)
 sackley(x, o=-32+64*runif(length(x)), fbias=-140)
 sgriewank(x, o=-600+1200*runif(length(x)), fbias=-180)
 srastrigin(x, o=-5+10*runif(length(x)), fbias=-330)
 srosenbrock(x, o=-100+200*runif(length(x)), fbias=390)
-sschwefel(x, o=-100+200*runif(length(x)), fbias=-450)
+sschwefel1_2(x, o=-100+200*runif(length(x)), fbias=-450)
 ssphere(x, o=-100+200*runif(length(x)), fbias=-450)
 
 }
@@ -73,6 +75,9 @@ GEATbx: Example Functions (single and multi-objective functions) \cr
 Problem Definitions and Evaluation Criteria for the CEC 2005 Special Session on Real-Parameter Optimization \cr
 \cite{\url{www.lri.fr/~hansen/Tech-Report-May-30-05.pdf}}
 
+Benchmark Problems \cr
+\cite{\url{http://www.cs.cmu.edu/afs/cs/project/jair/pub/volume24/ortizboyer05a-html/node6.html}}
+
 \cite{\url{http://www.zsd.ict.pwr.wroc.pl/files/docs/functions.pdf}}
 }
 \author{