converting a dict into a recarray. For example:

import numpy
v1=numpy.random.rand(10,)
v2=numpy.random.randint(10, size=10)
mydict={'v1':v1,'v2':v2}

#Conversion to a recarray begins
cols = [col for col in mydict.itervalues()]
ratype = [(name, col.dtype) for (name, col) in mydict.iteritems()]
ra=numpy.rec.fromarrays(cols, dtype=ratype)

# now, you can proceed to saving (and reading) the data
import tables
file = tables.openFile("test.h5", mode = "w")
tra3=f.createTable('/', 'ra3', ra)
file.root.ra3
file.close()