// version 1.0.0 14Feb2018
import com.stata.sfi.*;
public class MyCalcsW {

    public static int myAve( MyMatrix bmat, long firstObs, long lastObs, 
        int nVariables, MyLong nObs) {

        int    rc, varIndex ;
        double value ;
        String msg ;

        rc = 0 ;
// Loop over observations
        for(long obs=firstObs; obs<=lastObs; obs++) {
            if (!Data.isParsedIfTrue(obs)) {
                continue;
            }
            nObs.incrementValue() ;

// Loop over variables
            for(int var = 1; var<=nVariables; var++) {
// get the real variable index for parsed variable -var-
                varIndex = Data.mapParsedVarIndex(var);
// Put value of observation obs on variable varIndex into value
                value    = Data.getNum(varIndex, obs);

// Exit with error 
                if (Data.isValueMissing(value)) {
                    msg = "{err}missing values encountered" ;
                    SFIToolkit.errorln(msg);
                    return(416) ;
                }
// Increment sample average vector
                bmat.incrementByValue(0, var-1, value) ;
            }
        }
// Divide sample average vector by nObs
        bmat.divideByScalar((double) nObs.getValue()) ; 

        return (rc) ;
    }

    public static int myV( MyMatrix bmat, MyMatrix vmat, long firstObs, 
        long lastObs, int nVariables, MyLong nObs) {

        int      rc, varIndex  ; 
        MyMatrix emat ;
        double   value ;
        String   msg ;

        rc = 0 ;
// Create and initialized vector for observation level errors
        emat = new MyMatrix(1, nVariables);
// Loop over observations
        for(long obs=firstObs; obs<=lastObs; obs++) {
            if (!Data.isParsedIfTrue(obs)) {
                continue;
            }

// Loop over variables
            for(int var = 1; var<=nVariables; var++) {
// get the real variable index for parsed variable -var-
                varIndex = Data.mapParsedVarIndex(var);
// Put value of observation obs on variable varIndex into value
                value    = Data.getNum(varIndex, obs);

                if (Data.isValueMissing(value)) {
                    msg = "{err}missing values encountered" ;
                    SFIToolkit.errorln(msg);
                    return(416) ;
                }
                emat.storeValue(0, (var-1), bmat.getValue(0,(var-1)) - value) ;
            }

            for(int j = 0; j<nVariables; j++) {
                for(int j2 = 0; j2<=j; j2++) {
                    vmat.incrementByValue(j, j2, 
		        (emat.getValue(0,j)*emat.getValue(0,j2)));
                }
            }
        }

        for(int j = 0; j<nVariables; j++) {
            for(int j2 = j+1 ; j2<nVariables; j2++) {
                vmat.storeValue(j, j2, vmat.getValue(j2, j) ) ;
            }
        }

        double n2 = (double) nObs.getValue() ;
        n2        = n2*(n2-1)  ;
        vmat.divideByScalar( n2 ) ;

        return(rc) ;
    }

}