def startpoint(xyz):
    """ First point of the track

    Parameters
    -------------
    xyz : array, shape(N,3)
        Track.

    Returns
    ---------
    sp : array, shape(3,)
        First track point.

    Examples
    ----------
    >>> from dipy.tracking.metrics import startpoint
    >>> import numpy as np
    >>> theta=np.pi*np.linspace(0,1,100)
    >>> x=np.cos(theta)
    >>> y=np.sin(theta)
    >>> z=0*x
    >>> xyz=np.vstack((x,y,z)).T
    >>> sp=startpoint(xyz)
    >>> sp.any()==xyz[0].any()
    True

    """
    return xyz[0]
