Question

如何用matlab求解logistic模型

Answer 1

建立m函数文件存为logistic1functionf=logistic1(b)t=[0,5,10,24,33,48,57,72,96,120,144,168,192,216];y=[0,0.028,0.103,0.336,0.450,0.597,0.716,0.778,0.835,0.849,0.816,0.839,0.811,0.816];f=y-b(1)./(1+b(2).*exp(-b(3).*t));b0=[10,2,2];>>b=leastsq('logistic1',b0)b=0.822113.91730.0818或者cftoolGeneralmodel:f(x)=b/(1+a*exp(-k*x))Coefficients(with95%confidencebounds):a=13.92(6.301,21.53)b=0.822(0.7911,0.853)k=0.08184(0.06479,0.0989)Goodnessoffit:SSE:0.01404R-square:0.9898AdjustedR-square:0.9879RMSE:0.03572