Problem with ShakeGrid subdivide method on edges

[kallstadt-usgs]

from mapio.geodict import GeoDict
from mapio.shake import ShakeGrid
import matplotlib.pyplot as plt

shakefile = 'grid.xml' # Use 1906 San Francisco shakemap here

gdict = GeoDict({'xmin': -122.88698976549115,
'xmax': -122.2389795319979,
'ymin': 37.49798642716523,
'ymax': 38.065041960700796,
'dx': 9.315845794900122e-05,
'dy': 9.315845794900046e-05,
'ny': 6088,
'nx': 6957})

##% Load in ShakeMap
shakemap = ShakeGrid.load(shakefile, adjust='res')

##% Then subdivide to match smaller geodict
PGA = shakemap.getLayer('pga').subdivide(gdict).getData().astype(float)

'''
This leaves edges with values much lower than they should be (but not nodata)
causing problems on the edges in later calculations for ground failure
'''
plt.imshow(PGA)
plt.show()