Floating point minimum and maximum exponent values

Marco m.b at gmail.com
Tue Jul 16 13:43:37 CEST 2013

Hi all, why the maximum and minimum exp values are 1024 and -1021?:

 >>> sys.float_info
sys.float_info(max=1.7976931348623157e+308, max_exp=1024, 
max_10_exp=308, min=2.2250738585072014e-308, min_exp=-1021, 
min_10_exp=-307, dig=15, mant_dig=53, epsilon=2.220446049250313e-16, 
radix=2, rounds=1)

The values (in double precision) 0 and 2047 are reserved for zero, 
infinity and NaN (in combination with the fraction), so I was expecting 
-1022 and 1023...

Marco Buttu

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