def to_positive_idxs(shape, coord):
    """Return the positive index values.
    
    This function converts negative index values to positive index values.
    
    Args:
    
        shape (indexable sequence): The array shape.
        
        coord (indexable sequence): The coordinate pair for x and y.
        
    Returns:
        
        :obj:`list`: The coordinate values with all positive indexes.
        
    """
    if (coord[-2] >= 0 and coord[-1] >= 0):
        return coord
    
    return [x if (x >= 0) else shape[-i-1]+x for (i,x) in enumerate(coord)]