Curve Fitting error for two arrays

Question

Hisham 2014-5-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/128704-curve-fitting-error-for-two-arrays

回答： Hisham 2014-5-7

I have two arrays:

x=[    2180000;
     6070000;
    12700000;
    16600000;
    25000000;
    29400000;
    32200000;
    36100000;
    41600000;
    43900000;
    47200000;
    55000000
] 
y= [    1.0e-07*0.0953;
    1.0e-07*0.1060;
    1.0e-07*0.1220;
    1.0e-07*0.1290;
    1.0e-07*0.1480;
    1.0e-07*0.1580;
    1.0e-07*0.1880;
    1.0e-07*0.2510;
    1.0e-07*0.3210;
    1.0e-07*0.3510;
    1.0e-07*0.4470;
    1.0e-07*0.6090]

I used a custom equation as :

y=a*exp(-b/(4.14e-21))*exp(((3.2e-9)*(x))/((2)*(1.38e-23)*(300)))

but the problem that I found is : NaN computed by model function, fitting cannot continue. Try using or tightening upper and lower bounds on coefficients.

anyone knows idea of solving this problem?

Thanks!