推荐这个模型比较好。
General model Exp2:
f(x) = a*exp(b*x) + c*exp(d*x)
Coefficients (with 95% confidence bounds):
a = 2524 (2265, 2783)
b = 0.0003625 (-8.025e-005, 0.0008052)
c = -2244 (-2487, -2001)
d = -0.02828 (-0.03697, -0.01959)
Goodness of fit:
SSE: 2.165e+004
R-square: 0.9967
Adjusted R-square: 0.995
RMSE: 60.07
用cftool找模型,用法:
>> cftool
回车后,出现对话框,自己能看懂。对了对应x=150的那个值好像是2689.7942 而不是689.7942