©Ò¦³ªº ODE «ü¥O¥i¥H±µ¨ü²Ä¥|Ó¿é¤JÅܼơA¥Nªí¿n¤À¹Lµ{¥Î¨ìªº¦UºØ¿ï¶µ¡]Options¡^¡A¦¹ºØ ODE «ü¥Oªº®æ¦¡¬°¡G
[t, y] = solver('odeFile', [t0, tn], y0, options); ¨ä¤¤ options ¬O¥Ñ odeset «ü¥O¨Ó±±¨îªºµ²ºcÅܼơA¦¹µ²ºcÅܼƧY¥]§t¤F¿n¤À¹Lµ{¥Î¨ìªº¦UºØ¿ï¶µ¡Aodeset ªº¤@¯ë®æ¦¡¦p¤U¡G
options = odeset('name1', value1, 'name2', value2, ¡K) ¦¹®É²£¥Íªºµ²ºcÅÜ¼Æ options¡A¨äÄæ¦ì name1 ªºÈ¬° value1¡AÄæ¦ì name2 ªºÈ¬° value2¡A¨Ì¦¹Ãþ±À¡C¥¼³Q³]©wªºÄæ¦ì¡A¨äÄæ¦ìȧY¬°¹w³]È¡C
§Ṳ́]¥i¥H¥u§ïÅܤ@Ó²{¦sªº options µ²ºcÅܼƤ¤¡A¬YÓÄæ¦ìªºÈ¡A¨ä®æ¦¡¦p¤U¡G
newOptions = odeset(options, 'name', value); YnŪ¥X¬YÓÄæ¦ìªºÈ¡A¥i¥Î odeget¡A¨ä®æ¦¡¦p¤U¡G
value = odeget(otpions, 'name'); ¨ä¤¤ name ¬°Äæ¦ì¦WºÙ¡Avalue §Y¬°¹ïÀ³ªºÄæ¦ìÈ¡C
·í¨Ï¥Î odeset «ü¥O®É¡AYµL¥ô¦ó¿é¤JÅܼơA«h odeset ·|Åã¥Ü©Ò¦³ªºÄæ¦ì¦WºÙ¤ÎÄæ¦ìÈ¡A¨Ã¥H¤j¬A¸¹¥Nªí¹w³]È¡A¨Ò¦p¡G
³o¨ÇÄæ¦ì¦WºÙ¤Î¬ÛÃö»¡©ú¡A¥i¨£¤Uªí¡G
Ãþ§O Äæ¦ì¦WºÙ ¸ê®Æ«¬ºA ¹w³]È »¡©ú »~®t®e§Ô«×¤§¬ÛÃöÄæ¦ì RelTol ¥¿¯Â¶q $10^{-3}$ ¬Û¹ï»~®t®e§Ô«× AbsTo1 ¥¿¯Â¶q©Î¦V¶q $10^{-6}$ µ´¹ï»~®t®e§Ô«× ¿n¤À¿é¥X¤§¬ÛÃöÄæ©Ê OutPutFcn ¦r¦ê 'odeplot' ¿é¥X¨ç¦¡¡]Y ODE «ü¥OµL¿é¥XÅܼơA«h¦b¼ÆÈ¿n¤À°õ¦æ§¹²¦«á¡AMATLAB ·|©I¥s¦¹¿é¥X¨ç¦¡¡^ OutputSel ¯Á¤Þ¦V¶q ¥þ³¡ ODE «ü¥O¤§¿é¥XÅܼƪº¯Á¤ÞÈ¡A¥H¨M©w¨º¨Ç¿é¥XÅܼƤ§¤¸¯À±N³Q°e¨ì¿é¥X¨ç¦¡ Refine ¥¿¾ã¼Æ 1©Î4 (for ode45) Refine = 2 ¥i²£¥Í¨â¿¼Æ¶qªº¿é¥XÂI¡ARefine = 3 ¥i²£¥Í¤T¿¼Æ¶qªº¿é¥XÂI¡A¨Ì¦¹Ãþ±À¡C Stats on ©Î off off Stats = 'on' ²£¥Ípºâ¹Lµ{ªº¦UºØ²Îp¸ê®Æ¡C Jacobian ¯x°}¤§¬ÛÃöÄæ¦ì Jconstant on ©Î off off ¦pªG Jacobian ¯x°}±`¼Æ¡A«h Jconstant = 'on' Jacobian on ©Î off off YF(t, y, 'Jacobian') ¶Ç¦^ $\partial F/\partial y$¡A«h Jacobian = 'on' Jpattern on ©Î off off Y F([ ], [ ], 'JPattern') ¶Ç¦^ $\partial F/\partial y$¡A¥B $\partial F/\partial y$ ¬Oµ}²¨¯x°}¡A«h Jpattem = 'on' Vectorized on ©Î off off Y F(t, [y1, y2¡K..]) ¶Ç¦^ [F(t,y1), F(t,y2)¡K..]¡A«h Vectorized = 'on' ¿n¤À¨Bªø¡]Step Sizes¡^¤§¬ÛÃöÄæ¦ì Max Step ¥¿¯Â¶q ODE «ü¥O¤§¿n¤À¨Bªø ªº¤W Initial Step ¥¿¯Â¶q °_©l¨Bªøªº«ØÄ³È ½è¶q¯x°}¤§¬ÛÃöÄæ¦ì Mass none¡AM¡AM(t)¡A©Î M(t, y) none ªí©ú ODE «ü¥O®×¬O§_·|¶Ç¦^½è¶q¯x°} MassSingular yes¡Ano ©Î maybe maybe ªí©ú½è¶q¯x°}¬O§_¬° Singular ¨Æ¥óµo¥Í®É¶¡¤§¬ÛÃöÄæ¦ì Events on ©Î off off Y ODE ÀɮרöǦ^¨Æ¥ó¨ç¦¡¤Î¬ÛÃö¸ê°T¡A«h Events = 'on' Ode15s ¤§¬ÛÃöÄæ¦ì MaxOrder 1, 2, 3, 4 ©Î 5 5 ¿n¤À¤½¦¡¥Î¨ìªº³Ì°ª¦¸¼Æ BDF on ©Î off off Y¨Ï¥Î BDF¡]Backward Differentiation Formula¡^«h BDF = 'on' ¥H¤U¹ï´XÓ±`¥Î¨ìªºÄæ¦ì¨Ó¶i¦æ»¡©ú¡C
f ¦b¿n¤À»~®t®e§Ô«×¤è±¡A¨C¤@¦¸¿n¤À©Ò²£¥Íªº§½³¡»~®t e(i)¡A¥²¶·º¡¨¬¤U¦C¤èµ{¦¡¡G
$$ |e(i)| \leq max(RelTol*|y(i)|, AbsTol(i)) $$¨ä¤¤ i ¥Nªí²Ä i Óª¬ºAÅܼơA¦]¦¹¡A§ÚÌ¥i°§C RelTol ¤Î AbsTol ¨Ó¨D±o§óºë½Tªº¿n¤Àµ²ªG¡C¨Ò¦p¡G
¦b¤Wz½d¨Ò¤¤¡A²Ä¤@ӹϩҨϥΪº¬Û¹ï»~®tȬO0.01¡]¹w³]È¡^¡A²Ä¤GӹϩҨϥΪº¬Û¹ï»~®tȬO0.00001¡A¦]¦¹§Ú̱o¨ì¸û²Ó±KªºÂI¡A¦ý©Òªáªºpºâ®É¶¡¤]·|¤ñ¸ûªø¡C
¦b¿n¤À¿é¥Xªº¬ÛÃö³B²z¤è±¡A§ÚÌ¥i¥H¿ï¥Î¤@Ó OutputFcn¡A¨Ï±o·í ODE «ü¥O¨S¦³¿é¥XÅܼƮɡA¦¹¿é¥X¨ç¦¡ OutputFcn ·|³Q MATLAB ©I¥s¡COutputFcn ªº¹w³]ȬO¡¨odeplot¡¨¡A¨ä¥\¯à¬°µe¥X©Ò¦³ªºª¬ºAÅܼơA¨ä¥¦¥i¥Îªº¨ç¦¡ÁÙ¦³¡G
- odephas2¡Gµe¥X 2-D ªº¬Û¦ì¥±¡]Phase Plane¡^
- odephas3¡Gµe¥X 3-D ªº¬Û¦ì¥±
- odeprint¡GÀH®É¦b«ü¥Oµøµ¡¦L¥Xpºâµ²ªG
¥H Lorenz ´ý¨P¤èµ{¦¡¡]Lorenz Chaotic Equation¡^¬°¨Ò¡A¨ä ODE Àɮפ§¤º®e¥iÅã¥Ü¦p¤U¡G
±ý¨Ï¥Î ode45 ¹ï¤WzLorenz ´ý¨P¤èµ{¦¡¶i¦æ¼ÆÈ¿n¤À¡A¥i¨£¦¹½d¨Ò¡G
½Ðª`·N¦b¤W¦C¹Ï¤¤¡A¦@¦³¤T±ø¦±½u¡A¥Nªí¤TÓª¬ºAÅܼÆÀH®É¶¡Åܤƪº¹Ï§Î¡CYnµe¤T«×ªÅ¶¡¤§¬Û¦ì¹Ï§Î¡A¥i¨Ï¥Î¤U¦C½d¨Ò¡G
¤Wz¹Ï§Î¤¤¥u¥X²{¤@±ø¦±½u¡A¦¹¦±½u¥Nªí¥H¤TÓª¬ºAÅܼƬ°®y¼Ð¡B¥H®É¶¡¬°°Ñ¼Æªº¤@±ø¤T«×ªÅ¶¡¤¤ªº¦±½u¡C
¤@¯ë¦Ó¨¥¡A°²³]§Ú̪º OutputFcn ³]¦¨"myFunc"¡G
options = odeset('OutputFcn', 'myFunc') «h¦b¾ãÓ¿n¤À¹Lµ{¤¤¡AmyFunc ³Q©I¥sªº±¡ªp¦p¤U¡G
¦]¦¹¡AY§ÚÌn¦b¿n¤À¹Lµ{¤¤²£¥Í°Êµe¡A´N¥i¥H®Ú¾Ú¤Wzì«h¨Ó³]p myFunc.m¡C
- ¿n¤À¶}©l®É¡AODE «ü¥O·|©I¥s myFunc(tspan, y0, 'init') ¥HÅý myFunc ¶i¦æ¦UºØªì©l¤Æ°Ê§@¡C
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- ¦b¿n¤Àµ²§ô®É¡AODE «ü¥O·|©I¥s myFunc([], [], 'done')¡A¥HÅý myFunc ¶i¦æ¦¬§À°Ê§@¡C
OutputSel ¥i«ü©wn¶Ç°e¨ì OutputFcn ªºª¬ºAÅܼƤ§¤¸¯À¡C¨Ò¦p¡AY¥un¶Ç°e²Ä¤@¤Î²Ä¤TÓ Lorenz ´ý¨P¤èµ{¦¡ªºª¬ºAÅÊ¼Æ¦Ü odeplot¡A¥i¿é¤J¦p¤U¡G
¦b¤W¹Ï¤¤¡A§ÚÌ¥uµe¥X¤F²Ä¤@©M²Ä¤TÓª¬ºAÅܼơC
Refine Äæ¦ì¥i¥H¨Ï¥Î¤º´¡ªk¨Ó¼W¥[¿é¥Xª¬ºAÅܼƪº±K«×¡A¥H±o¨ì¸û¥·Æªº¿é¥X¦±½u¡C¦b¤U¨Ò¤¤¡A§Ú̧Q¥Î Refine Äæ¦ì¨Ó¨Ï ode23 ªº¿é¥XÂIӼƼW¬°ì¥ýªº¤T¿¡G
·í Stat=on ®É¡AODE «ü¥O·|¦b°õ¦æ§¹²¦«áÅã¥Üpºâ¹Lµ{ªº¦UºØ²Îp¼Æ¦r¡A¨Ò¦p¡G
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MaxStep ¤Î InitialStep Äæ¦ì¥i¥Î¨Ó½Õ¾ã³Ì¤j¿n¤À¨Bªø¤Î°_©l¿n¤À¨Bªø¡C¦ý¤@¯ë¦Ó¨¥¡A±z¤£¥²¥h½Õ¾ã³o¨âÓ¼ÆÈ¡A¦]¬° ODE «ü¥O¥»¨´N¨ã¦³¨Bªø¦Û°Ê½Õ¾A¥\¯à¡C¯S§Oȱoª`·Nªº¬O¡G
- Yn²£¥Í§ó¦h¿é¥XÂI¡A¥iª½±µ½Õ¾ã Refine Äæ¦ìÈ¡C½Õ¾ã MaxStep ÁöµM¥i¥H¹F¨ì¦P¼Ë®ÄªG¡A¦ý¬Opºâ®É¶¡¥i¯à·|¤j´T¼W¥[¡C
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