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¦b«e¤@¸`¤¤¡A§Ú­Ì¤wª¾¹D°ò¥» ODE Àɮתº¼gªk¡A¦p vdp1.m¡Bvdp2.m ¤Î lorenzOde.m µ¥¡C¦b¥»¸`¤¤¡A±N§ó¶i¤@¨B¤¶²Ð ODE Àɮתº¶i¶¥¥Îªk¡A¥H¨Ï ODE «ü¥O¯à°÷¨³³t¥B·Ç½T¦aºâ¥X¿n¤Àµ²ªG¡C

­º¥ý¡A§Ú­Ì¥i±N tspan¡]¿n¤À®É¶¡½d³ò¡^¡By0¡]°_©l­È¡^¤Î options¡]ODE°Ñ¼Æ¡^¸m©ó ODE Àɮפ¤¡A³o¨ÇÅܼƥ²¶·¯à¥Ñ ODE Àɮ׶Ǧ^¡A¨ä®æ¦¡¬°¡G

[tspan, y0, options] = odeFile([], [], 'init')

¨ä¤¤§Ú­Ì°²³] odeFile §Y¬O§Ú­Ìªº ODE ÀɮסC­Y odeFile º¡¨¬¤W­z­n¨D¡A«h§Ú­Ì¥i¥Hª½±µ©I¥s ODE «ü¥O¦p¤U¡G

[t, y] = solver('odeFile')

¨ä¤¤ solver ¬°«e­zªº¥ô¤@­Ó ODE «ü¥O¡A¥¦¥i¥Ñ odeFile ª½±µ±o¨ì tspan¡By0 ¤Î options µ¥¿n¤À©Ò»Ýªº¸ê°T¡C

¥H«e­zªº van der Pol ¬°¨Ò¡A­Y­n¯à°÷¶Ç¦^ tspan¡By0 ¤Î options¡Avdp1.m ¶·§ï¼g¦p¤U¡]vdp3.m¡^¡G

11-±`·L¤À¤èµ{¦¡/vdp3.mfunction [output1, output2, output3] = vdp3(t, y, flag) if strcmp(flag, '') mu = 1; output1 = [y(2); mu*(1-y(1)^2)*y(2)-y(1)]; % dy/dt elseif strcmp(flag, 'init'), output1 = [0; 25]; % Time span output2 = [3; 3]; % Initial conditions output3 = odeset; % ODE options end

¦¹®É§Ú­Ì¥i¥Hª½±µ©I¥s ODE «ü¥O¦p¤U¡G

Example 1: 11-±`·L¤À¤èµ{¦¡/odeAdvanced01.mode45('vdp3')

¦¹¥~¡Avan der Pol ªº·L¤À¤èµ{¦¡¦³¤@­Ó°Ñ¼Æ $\mu$¡A­Y§Æ±æ±q¥~­±¶Ç¤J¦¹°Ñ¼Æªº­È¡A§Ú­Ì¥i±N vdp3.m §ï¼g¦¨vdp4.m¡A¨ä¤º®e¦p¤U¡G

11-±`·L¤À¤èµ{¦¡/vdp4.mfunction [output1, output2, output3] = vdp4(t, y, flag, mu) if nargin < 4 | isempty(mu), mu = 1; end if strcmp(flag, '') output1 = [y(2); mu*(1-y(1)^2)*y(2)-y(1)]; % dy/dt elseif strcmp(flag, 'init'), output1 = [0; 25]; % Time span output2 = [3; 3]; % Initial conditions output3 = odeset; % ODE options end

¦¹®É $\mu$ ´NÅܦ¨¤@­Ó¿ï¾Ü©Ê¡]Optional¡^ªº°Ñ¼Æ¡A¨ä¹w³]­È¬° 1¡C¦b¤U¨Ò¤¤¡A§Ú­Ì±N $\mu$ ªº­È±q MATLAB ¶Ç¤J¡A¨Ãµe¥X¤£¦P $\mu$ ­È¤Uªº van der Pol ¤èµ{¦¡ªºª¬ºAÅܼơG

Example 2: 11-±`·L¤À¤èµ{¦¡/odeAdvanced02.msubplot(2,1,1); ode45('vdp4', [], [], [], 1); % mu=1 subplot(2,1,2); ode45('vdp4', [], [], [], 3); % mu=3

¦b¤W¹Ï¤¤¡A$\mu$ ªº­È¤À§O¬O 1 ¤Î 3¡C«ü¥O¦C¤¤¥Î¨ì¤F³\¦hªÅ¯x°}¡A³o¨ÇªÅ¯x°}¥Nªí¡u¨ú¥Î¹w³]­È¡v¡A¦]¦¹ ode45 ·|ª½±µ±q vdp4.m ¨ú¥Î®É¶¡°Ï¶¡¤ÎÅܼư_©l­È¡C¨Æ¹ê¤W¡A±z¤]¥i¥H¶Ç¤J¤G­Ó©Î§ó¦hªº°Ñ¼Æ¡AMATLAB ¤Î ODE «ü¥O¹ï©ó¥i¶Ç¤Jªº°Ñ¼Æ­Ó¼Æ¨ÃµL³]­­¡C

¦¹¥~¡A¬°¸Ñ¨M¨ä¥¦¸û½ÆÂøªº ODEs ¤Î DAEs¡]Differential Algebra Equations¡^¡AODE ÀÉ®×¥ç¥i¦b¤£¦PªººX¸¹¡]Flag¡^¤U¶Ç¦^¤£¦Pªº¸ê°T¡A¥H¤U¬O¤@­Ó§¹¾ãªº¦Cªí¡G

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