def gradient(self):
        """Gradient operator of the functional."""
        return (self.functional.gradient +
                (2 * self.quadratic_coeff) * IdentityOperator(self.domain) +
                ConstantOperator(self.linear_term))
def gradient ( self ) : return ( self . functional . gradient + ( 2 * self . quadratic_coeff ) * IdentityOperator ( self . domain ) + ConstantOperator ( self . linear_term ) )
Gradient operator of the functional.