Playing with regular hexagons using DataArrayDouble

import MEDCoupling as mc
import math
# Building the coordinates of the initial hexagon, centered at 0,0
d = mc.DataArrayDouble(6,2)
d[:,0] = 3.
d[:,1] = range(6)
d[:,1] *= math.pi/3.
d = d.fromPolarToCart()
d.setInfoOnComponents(["X [m]","Y [m]"])
print d.getValues()
print d
print "Uniform array?", d.magnitude().isUniform(3.,1e-12)
# Translating the 7 hexagons with a translation
radius = 3.
translationToPerform = [[0.,0.],[3./2.*radius,-radius*math.sqrt(3.)/2],[3./2.*radius,radius*math.sqrt(3.)/2],[0.,radius*math.sqrt(3.)],[-3./2.*radius,radius*math.sqrt(3.)/2],[-3./2.*radius,-radius*math.sqrt(3.)/2],[0.,-radius*math.sqrt(3.)]]
ds = len(translationToPerform)*[None]
for pos,t in enumerate(translationToPerform):
                 ds[pos] = d[:]         # Perform a deep copy of d and place it at position 'pos' in ds
                 ds[pos] += t             # Adding a vector to a set of coordinates does a translation
                 pass
# Identifying duplicate tuples
d2 = mc.DataArrayDouble.Aggregate(ds)
oldNbOfTuples = d2.getNumberOfTuples()
c,cI = d2.findCommonTuples(1e-12)
tmp = c[cI[0]:cI[0+1]]
print tmp
a = cI.deltaShiftIndex()
b = a - 1
myNewNbOfTuples = oldNbOfTuples - sum(b.getValues())
o2n, newNbOfTuples = mc.DataArrayInt.ConvertIndexArrayToO2N(oldNbOfTuples,c,cI)
print "Have I got the right number of tuples?"
print "myNewNbOfTuples = %d, newNbOfTuples = %d" % (myNewNbOfTuples, newNbOfTuples)
assert(myNewNbOfTuples == newNbOfTuples)
# Extracting the unique set of tuples
d3 = d2.renumberAndReduce(o2n, newNbOfTuples)
n2o = o2n.invertArrayO2N2N2O(newNbOfTuples)
d3_bis = d2[n2o]
print "Are d3 and d3_bis equal ? %s" % (str(d3.isEqual(d3_bis, 1e-12)))
# Now translate everything
d3 += [3.3,4.4]
# And build an unstructured mesh representing the final pattern
m = mc.MEDCouplingUMesh("My7hexagons",2)
m.setCoords(d3)
print "Mesh dimension is", m.getMeshDimension()
print "Spatial dimension is", m.getCoords().getNumberOfComponents()
m.allocateCells(7)
for i in xrange(7):
        cell_connec = o2n[6*i:6*(i+1)]
        m.insertNextCell(mc.NORM_POLYGON, cell_connec.getValues())
        pass
# Check that everything is coherent (will throw if not)
m.checkConsistencyLight()
# Write the result into a VTU file that can be read with ParaView
m.writeVTK("My7hexagons.vtu")