Re: NSolve problem
- To: mathgroup at smc.vnet.net
- Subject: [mg27810] Re: NSolve problem
- From: BobHanlon at aol.com
- Date: Mon, 19 Mar 2001 01:29:01 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I think that you need to ensure that the function has higher precision than NSolve to avoid the problem on a Mac. coef={ 56948086997945333979944420780869994640, -410398690910611254706353259635396975000, 1438562129094179414396635651311443079894, -3267975175700805824009526616434042764990, 5408604513390527799203743488644413596831, -6950806520792700621314978752272893634603, 7219321171308545919834020175759542752800, -6227602171254861022800069187941498698916, 4550488627005201158356170201262005359426, -2858356540987341736071315091852197268914, 1561105298212051506376403179694366814908, -747964023676923486311300650584136934167, 316623088476789267411001214031813664920, -119092149085329990604796332906238009003, 39983125143255083338516711567117321554, -12025273387738045949766927419057733779, 3249150512801263497674821800877444750, -790386259690389861011499411484727356, 173372427244970231511243462159022530, -34326439784958730341338590620522553, 6137577944863948353668001351379085, -991008485501837267612722683739742, 144425378677250071307785407099514, -18977700242148569406030260324295, 2244844544457248209076495840902, -238516616444064255358326013794, 22698320261526730755198553574, -1927635748101251322270468277, 145419622102662664506687100, -9689635918166905495882851, 566216540434141788242036, -28757943661703317295081, 1255110040775305672800, -46379987523224586918, 1422785868781829532, -35256637347077513, 678033800618890, -9494410812843, 86108525122, -379610373}; f[x_, n_Integer?Positive] := Module[{r = Rationalize[x, 10^(-n)]}, Fold[#1*r+#2&, 0, coef]]; Plot[f[x, 10], {x, 0.07, 0.3}, PlotRange -> {-0.2, 0.2}, Frame -> True, Axes -> False]; $Version "4.1 for Power Macintosh (November 2, 2000)" soln[n_Integer?Positive] := NSolve[f[x, n+2] == 0, x, n]; soln[40] {{x -> 0.091708830141284216611300718338731`19.4702}, {x -> 0.1104974690580543250922644165`11.2476}, {x -> 0.1105873420815579159995547312`11.2124}, {x -> 0.1159375392511005425478689904`11.1591}, {x -> 0.1236583455659158388708928991`8.936}, {x -> 0.1293265537217207399`5.927}, {x -> 0.129623393195697322`5.8156}, {x -> 0.1319667912920863781`6.1616}, {x -> 0.1349687561339759892`6.2469}, {x -> 0.142384485487523896`5.9727}, {x -> 0.15914888842593`0.9405}, {x -> 0.15962702427223`0.7091}, {x -> 0.16166699861575`0.718}, {x -> 0.16429234912329`0.6458}, {x -> 0.16795200596333`0.6536}, {x -> 0.17006072687201`3.5496 - 0.01271216354109`2.4232*I}, {x -> 0.17006072687201`3.5496 + 0.01271216354109`2.4232*I}, {x -> 0.17452263754768`0.6021}, {x -> 0.17572478144437`0.6021}, {x -> 0.18213053535748`0.6021}, {x -> 0.18466999394585`0.8245}, {x -> 0.21276062833504`0.6021}, {x -> 0.21537305189043`0.6021}, {x -> 0.21667300164505`0.6021}, {x -> 0.21813564609871`0.6021}, {x -> 0.2184316522117`0.6021}, {x -> 0.22139975315691`0.6021}, {x -> 0.22279244101398`0.6021}, {x -> 0.22322749819878`0.6021}, {x -> 0.22433690122262`0.6021}, {x -> 0.23212762586955`0.6021}, {x -> 0.23319584770714`0.6021}, {x -> 0.23430535006292`0.6021}, {x -> 0.23733771094056`0.6021}, {x -> 0.2392655206455`0.6021}, {x -> 0.240928788821`0.6021}, {x -> 0.24126406796542`0.6021}, {x -> 0.24206076730204`0.6021}, {x -> 0.24240799462008`0.6021}} Bob Hanlon In a message dated 2001/3/9 3:00:14 AM, mtpagesj at lg.ehu.es writes: >My problem was that Mathematica crashed on an iMac and a G4 when >evaluating NSolve[poly==0,x], where poly is given below. There have been >several posts by Windows users saying that they found no problem. I would >like to hear from MacIntosh users. > > Thanks, > > Julian Aguirre > Universidad del Pais Vasco > >> > poly = >> > -379610373 + >> > 86108525122 x - >> > 9494410812843 x^2 + >> > 678033800618890 x^3 - >> > 35256637347077513 x^4 + >> > 1422785868781829532 x^5 - >> > 46379987523224586918 x^6 + >> > 1255110040775305672800 x^7 - >> > 28757943661703317295081 x^8 + >> > 566216540434141788242036 x^9 - >> > 9689635918166905495882851 x^10 + >> > 145419622102662664506687100 x^11 - >> > 1927635748101251322270468277 x^12 + >> > 22698320261526730755198553574 x^13 - >> > 238516616444064255358326013794 x^14 + >> > 2244844544457248209076495840902 x^15 - >> > 18977700242148569406030260324295 x^16 + >> > 144425378677250071307785407099514 x^17 - >> > 991008485501837267612722683739742 x^18 + >> > 6137577944863948353668001351379085 x^19 - >> > 34326439784958730341338590620522553 x^20 + >> > 173372427244970231511243462159022530 x^21 - >> > 790386259690389861011499411484727356 x^22 + >> > 3249150512801263497674821800877444750 x^23 - >> > 12025273387738045949766927419057733779 x^24 + >> > 39983125143255083338516711567117321554 x^25 - >> > 119092149085329990604796332906238009003 x^26 + >> > 316623088476789267411001214031813664920 x^27 - >> > 747964023676923486311300650584136934167 x^28 + >> > 1561105298212051506376403179694366814908 x^29 - >> > 2858356540987341736071315091852197268914 x^30 + >> > 4550488627005201158356170201262005359426 x^31 - >> > 6227602171254861022800069187941498698916 x^32 + >> > 7219321171308545919834020175759542752800 x^33 - >> > 6950806520792700621314978752272893634603 x^34 + >> > 5408604513390527799203743488644413596831 x^35 - >> > 3267975175700805824009526616434042764990 x^36 + >> > 1438562129094179414396635651311443079894 x^37 - >> > 410398690910611254706353259635396975000 x^38 + >> > 56948086997945333979944420780869994640 x^39;