[求助] 根据数据和方程的形式，求方程中的参数

x=[1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4];
y=[10363972.36
5697599.795
3269017.372
1948866.775
1202604.284
765578.5464
501320.0508
336809.4864
231640.3371
162754.7914
116618.904
85080.3473
63109.81473
47535.43773];
st_ = [1000 -2 -1];
ft_ = fittype('a*exp(-p/(x+q))','dependent',{'y'},'independent',{'x'},'coefficients',{'a', 'p','q'});
[cf_,good]= fit(x,y,ft_ ,'Startpoint',st_)
h_ = plot(cf_,'fit',0.95);
legend off;  % turn off legend from plot method call
set(h_(1),'Color',[1 0 0],...
     'LineStyle','-', 'LineWidth',2,...
     'Marker','none', 'MarkerSize',6);
hold on,plot(x,y,'*')

楼: Originally posted by 715211229 at 2011-12-20 05:28:41:
matlab ：ctool工具箱
%%%拟合效果很差

Fit computation did not converge:
Maximum number of function evaluations exceeded. Increasing
MaxFunEvals (in fit options) may allow  ...