[math-fun] Fwd: about bugs in mathematica and pari-gp
My old Macsyma gets (c71) PRIME(8200000000); (d71) 205021987301 (c72) PRIME(9300000000); (d72) 233746743437 SPlouffe>Hello, here is a strange bug, type Prime[8200000000] or Prime[93000000000] in mathematica and your machine will hang forever.... rwg> No, mine is powered by PG&E. and by a bizarre coincidence, the same thing happens with pari-gp with the value prime(8200000000), I could not test 93 000 000 000 because it is out of reach for pari-gp (I think). Does anybody has any idea why the programs are bugging on these particular values ? rwg>NSA back door.
In[156]:= Prime[8200000001] // tim
During evaluation of In[156]:= 0.539572 (secs)
Out[156]= 205021987381 Macsyma took minutes.
Best regards and have a nice day. Simon Plouffe ___________________________
Ah, here's your problem: You weren't using the latest unreleased version of Mathematica. In[463]:= $Version Out[463]= "12.0.0 for Mac OS X x86 (64-bit) (February 25, 2019)" In[460]:= Prime[8200000000] // tim During evaluation of In[460]:= 9757.614305 (Less than *e* hours!-) Out[460]= 205021987301 Versus sneaking up on it: In[453]:= ClearSystemCache[]; NextPrime@Prime@8199999999 // tim During evaluation of In[453]:= 0.643667 (seconds) Out[453]= 205021987301 —rwg On Sun, May 26, 2019 at 12:54 AM Bill Gosper <billgosper@gmail.com> wrote:
My old Macsyma gets
(c71) PRIME(8200000000);
(d71) 205021987301
(c72) PRIME(9300000000);
(d72) 233746743437
SPlouffe>Hello,
here is a strange bug,
type Prime[8200000000] or Prime[93000000000] in mathematica and your machine will hang forever....
rwg> No, mine is powered by PG&E.
and by a bizarre coincidence, the same thing happens with pari-gp with the value prime(8200000000), I could not test 93 000 000 000 because it is out of reach for pari-gp (I think).
Does anybody has any idea why the programs are bugging on these particular values ?
rwg>NSA back door.
In[156]:= Prime[8200000001] // tim
During evaluation of In[156]:= 0.539572 (secs)
Out[156]= 205021987381 Macsyma took minutes.
Best regards and have a nice day. Simon Plouffe ___________________________
I think that macsyma is wrong about 93 * 10^9: time ./primecount -n 93000000000 2560462462787 real 0m0.143s user 0m0.106s sys 0m0.004s time ./primecount 2560462462787 93000000000 real 0m0.106s user 0m0.101s sys 0m0.004s time ./primecount 2560462462786 92999999999 real 0m0.106s user 0m0.101s sys 0m0.004s On Sun, May 26, 2019 at 3:54 AM Bill Gosper <billgosper@gmail.com> wrote:
My old Macsyma gets
(c71) PRIME(8200000000);
(d71) 205021987301
(c72) PRIME(9300000000);
(d72) 233746743437
SPlouffe>Hello,
here is a strange bug,
type Prime[8200000000] or Prime[93000000000] in mathematica and your machine will hang forever....
rwg> No, mine is powered by PG&E.
and by a bizarre coincidence, the same thing happens with pari-gp with the value prime(8200000000), I could not test 93 000 000 000 because it is out of reach for pari-gp (I think).
Does anybody has any idea why the programs are bugging on these particular values ?
rwg>NSA back door.
In[156]:= Prime[8200000001] // tim
During evaluation of In[156]:= 0.539572 (secs)
Out[156]= 205021987381 Macsyma took minutes.
Best regards and have a nice day. Simon Plouffe ___________________________ _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (2)
-
Bill Gosper -
Victor Miller