nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/util/ComplexUtil.java
public static IComplexNumber atan(IComplexNumber num) {
        Complex c = new Complex(num.realComponent().doubleValue(), num.imaginaryComponent().doubleValue()).atan();
        return Nd4j.createDouble(c.getReal(), c.getImaginary());
    }
public static IComplexNumber atan(IComplexNumber num) {
        Complex c = new Complex(num.realComponent().doubleValue(), num.imaginaryComponent().doubleValue()).atan();
        return Nd4j.createDouble(c.getReal(), c.getImaginary());
    }
Return the  sin value of the given complex number

@param num the number to getScalar the absolute value for
@return the absolute value of this complex number