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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def minimum_image( self, r1, r2 ):
 """ Find the minimum image vector from point r1 to point r2. Args: r1 (np.array):
 fractional coordinates of point r1. r2 (np.array):
 fractional coordinates of point r2. Returns: (np.array):
 the fractional coordinate vector from r1 to the nearest image of r2. """

        delta_r = r2 - r1
        delta_r = np.array( [ x - math.copysign( 1.0, x ) if abs(x) > 0.5 else x for x in delta_r ] )
        return( delta_r )