gromacs/fileformats/convert.py
def to_int64(a):
    """Return view of the recarray with all int32 cast to int64."""
    # build new dtype and replace i4 --> i8
    def promote_i4(typestr):
        if typestr[1:] == 'i4':
            typestr = typestr[0]+'i8'
        return typestr

    dtype = [(name, promote_i4(typestr)) for name,typestr in a.dtype.descr]
    return a.astype(dtype)
def to_int64(a):
    """Return view of the recarray with all int32 cast to int64."""
    # build new dtype and replace i4 --> i8
    def promote_i4(typestr):
        if typestr[1:] == 'i4':
            typestr = typestr[0]+'i8'
        return typestr

    dtype = [(name, promote_i4(typestr)) for name,typestr in a.dtype.descr]
    return a.astype(dtype)
Return view of the recarray with all int32 cast to int64.