Returns the minimal pitch between two neighboring nodes of the mesh in each direction.

        :return: Minimal pitch in each direction.

def minimum_pitch(self):
        """ Returns the minimal pitch between two neighboring nodes of the mesh in each direction.

        :return: Minimal pitch in each direction.
        """
        pitch = self.pitch
        minimal_pitch = []

        for p in pitch:
            minimal_pitch.append(min(p))

        return min(minimal_pitch)