Complex r1 = Complex.I.mul(2.0*pi*5.0*i/nn[0]);
Complex r2 = Complex.I.mul(2.0*pi*7.0*j/nn[1]);
Complex r3 = Complex.I.mul(2.0*pi*9.0*k/nn[2]);
Complex r = r1.exp().mul(r2.exp()).mul(r3.exp());
data4[i][j][2*k] = r.re();
data4[i][j][2*k+1] = r.im();
/*
data4[i][j][2*k]=real(exp(2.0*Complex(0.0,1.0)*pi*5.0*double(i)/double(nn[0]))
*exp(2.0*Complex(0.0,1.0)*pi*7.0*double(j)/double(nn[1]))
*exp(2.0*Complex(0.0,1.0)*pi*9.0*double(k)/double(nn[2])));
data4[i][j][2*k+1]=imag(exp(2.0*Complex(0.0,1.0)*pi*5.0*double(i)/double(nn[0]))