42 views

Skip to first unread message

May 4, 2014, 2:28:55 AM5/4/14

to

Mathematica 9.0 .. on a 32 bit windows machine.

f[n_] := Block[{k = f[n - 1]}, {k, k}]

f[0]=x

LeafCount[f[k]] for particular small integers k

returns the number 2^(k+1)-1. e.g. for k=3, it returns 15.

But it returns the same answer for k=30, 31, ....

It returns 2147483647, which, probably not coincidentally, is 2^31-1.

ByteCount has a similar problem in running out of bits in

its counter.

Anyway, ByteCount also lies in a different way...

because it doesn't take into account the

sharing that (say) f[70] has. Without the sharing

implicit in the formula above, I could not compute that --

it has 2.36 X 10^21 leaves. They are just not different leaves.

I would expect that a 64-bit system might work for k=31,

but would conk out somewhere else.

f[n_] := Block[{k = f[n - 1]}, {k, k}]

f[0]=x

LeafCount[f[k]] for particular small integers k

returns the number 2^(k+1)-1. e.g. for k=3, it returns 15.

But it returns the same answer for k=30, 31, ....

It returns 2147483647, which, probably not coincidentally, is 2^31-1.

ByteCount has a similar problem in running out of bits in

its counter.

Anyway, ByteCount also lies in a different way...

because it doesn't take into account the

sharing that (say) f[70] has. Without the sharing

implicit in the formula above, I could not compute that --

it has 2.36 X 10^21 leaves. They are just not different leaves.

I would expect that a 64-bit system might work for k=31,

but would conk out somewhere else.

Reply all

Reply to author

Forward

0 new messages

Search

Clear search

Close search

Google apps

Main menu