Class to apply amplification from the GMPE tables.
Attr shape:  Shape of the amplification arrays as a tuple of (Number Distances, Number IMTs, Number Magnitudes, Number Amplification Levels) 

Attr periods:  Spectral periods defined in table 
Attr mean:  Amplification factors for the mean ground motion 
Attr sigma:  List of modification factors for the standard deviation of ground motion 
Attr magnitudes:  
Magnitude values for the tables  
Attr distances:  Distance values for the tables 
Attr parameter:  Parameter to which the amplification applies. Must be an element inside the _slots_ defines in the :class: openquake.hazardlib. gsim.base.RuptureContext or the :class: openquake.hazardlib.gsim.base. SitesContext 
Attr values:  Array of values to which each amplification table corresponds 
Attr element:  Indicates if the amplification corresponds to a rupture attribute or a site attribute 
Returns the amplification factors for the given rupture and site conditions.
Parameters: 


Returns: 

Implements ground motion prediction equations in the form of a table from which the expected ground motion intensity levels and standard deviations are interpolated.
In a GMPE tables the expected ground motions for each of the IMTs over the range of magnitudes and distances are stored in an hdf5 file on the path specified by the user.
In this version of the GMPE the expected values are interpolated to the required IMT, magnitude and distance in three stages.