Put a scalar.

def put_scalar(self, name, val):
        """
        Put a scalar.
        """
        if isinstance(val, np.floating):
            val = float(val)
        if isinstance(val, np.integer):
            val = int(val)
        self._dispatch(lambda m: m.process_scalar(name, val))
        s = create_scalar_summary(name, val)
        self._dispatch(lambda m: m.process_summary(s))