.max of FRDRV does not work properly

[pelegm]

For example,

In [1]: import drv.real

In [2]: ps = [1, 1, 2, 3, 5, 0, 13, 21, 34, 0]

In [3]: fp = drv.pspace.FDPSpace(ps)

In [4]: fr = drv.real.FRDRV('fr', fp, lambda x: x ** 2)

In [5]: fr.max
Out[5]: 81

In [6]: fr.xs
Out[6]: [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

In [7]: fr.ps
Out[7]: [0.0125, 0.0125, 0.025, 0.0375, 0.0625, 0.0, 0.1625, 0.2625, 0.425, 0.0]

The maximum of the random variable should clearly be 64.