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matlab-常微分方程參數(shù)估計(jì)
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初始數(shù)據(jù)濃度和時(shí)間 t=[0,10,30,50,70,90,110,130,150,160]; c=[0,0.23211,0.45906,0.68601,0.92328,1.21213,1.32561,1.34624,1.39782,1.398]; 微分方程,dc/dt=[4.41/96485-(4.41*k+L*4.41/96485)c]/(1+4.41*k*t) 要求: 1.得到擬合參數(shù):k 和L 以及相對(duì)偏差 2.得到擬合曲線和數(shù)據(jù)點(diǎn)的圖 3.最好附上院程序 |
榮譽(yù)版主 (著名寫手)
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本人編寫的程序如下但是無法運(yùn)行,由于是新手,希望高手幫忙調(diào)試一下: function PenicilliumEst clear all; t=[0,10,30,50,70,90,110,130,150,160]; y=[0,0.23211,0.45906,0.68601,0.92328,1.21213,1.32561,1.34624,1.39782,1.398]; y0=0; % Nonlinear least square estimate using lsqnonlin() beta0=[0.005 0.001]; lb=[0 0];ub=[inf inf]; [beta,resnorm,residual,exitflag,output,lambda,jacobian] = ... lsqnonlin(@Func,beta0,lb,ub,[],t,y); ci = nlparci(beta,residual,jacobian); % ======================================= function f = Func(beta,t,y,y0) % Define objective function tspan = [0 max(x)]; [tt yy] = ode45(@ModelEqs,tspan,y0,[],beta); yc= spline(tt,yy,x); f1=y-yc % ================================== function dydt = ModelEqs(t,y,beta) % Model equations dydt = [4.41/96485-(4.41*beta(1)+beta(2)*4.41/96485)*y]/(1+4.41*beta(1)*t) % result fprintf('\n Estimated Parameters by Lsqnonlin():\n') fprintf('\t k1 = %.4f ± %.4f\n',beta(1),ci(1,2)-beta(1)) fprintf('\t k2 = %.4f ± %.4f\n',beta(2),ci(2,2)-beta(2)) fprintf(' The sum of the residual squares is: %.1e\n\n',sum(residual.^2)) % plot of fit results tspan = [0 max(t)]; [tt yc] = ode45(@modeleqs,tspan,c0,[],beta); tc=linspace(0,max(t),200); yc = spline(tt,yc,tc); plot(t,c,'ro',tc,yca,'r-'); hold on xlabel('Time'); ylabel('Concentration'); hold off |
鐵桿木蟲 (職業(yè)作家)
木蟲 (職業(yè)作家)

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Title "model"; Parameters k, L; Variable t,c; ODEFunction c'=(4.41/96485-(4.41*k+L*4.41/96485)*c)/(1+4.41*k*t); Data; 0 0.02063 600 0.23211 1800 0.45906 3000 0.68601 4200 0.92328 5400 1.21213 6600 1.32561 7800 1.34624 9000 1.39782 9600 1.398 但是沒有計(jì)算出結(jié)果,我的選擇的優(yōu)化算法是第一種, 版本是1.5,請(qǐng)問為什么 |
鐵桿木蟲 (職業(yè)作家)
鐵桿木蟲 (職業(yè)作家)
鐵桿木蟲 (職業(yè)作家)
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