question: public static void CF2 ( double [ ] x , double [ ] f , double [ ] c , int nx ) { int count1 = 0 ; int count2 = 0 ; double sum1 = 0.0 ; double sum2 = 0.0 ; double yj ; double N = 2.0 ; double a = 1.0 ; double t ; for ( int j = 2 ; j <= nx ; j ++ ) { yj = x [ j - 1 ] - Math . sin ( 6.0 * PI * x [ 0 ] + j * PI / nx ) ; if ( j % 2 == 1 ) { yj = x [ j - 1 ] - Math . sin ( 6.0 * PI * x [ 0 ] + j * PI / nx ) ; sum1 += yj * yj ; count1 ++ ; } else { yj = x [ j - 1 ] - Math . cos ( 6.0 * PI * x [ 0 ] + j * PI / nx ) ; sum2 += yj * yj ; count2 ++ ; } } f [ 0 ] = x [ 0 ] + 2.0 * sum1 / ( double ) count1 ; f [ 1 ] = 1.0 - Math . sqrt ( x [ 0 ] ) + 2.0 * sum2 / ( double ) count2 ; t = f [ 1 ] + Math . sqrt ( f [ 0 ] ) - a * Math . sin ( N * PI * ( Math . sqrt ( f [ 0 ] ) - f [ 1 ] + 1.0 ) ) - 1.0 ; c [ 0 ] = MYSIGN ( t ) * Math . abs ( t ) / ( 1 + Math . exp ( 4.0 * Math . abs ( t ) ) ) ; }
target:  Evaluates the CF2 problem.