Hi, Em, if fit as the function: y=y0.exp((x0/x)^v), then the result will be about:
Root of Mean Square Error (RMSE): 9.39279339716383E-8
Sum of Squared Residual: 2.20561419504511E-13
Correlation Coef. (R): 0.82258630535955
R-Square: 0.676648229765075
Parameter Best Estimate
---------- -------------
y0 5.04851528699078E-118
x0 8.3186904534098E-210
v -0.0113812101308709
While, if change your fit function from " y=y0.exp((x0/x)^v)" to " y=y0.exp(x0^v/x^v)", take x0^v as x1, the function become: y=y0.exp(x1/x^v), the result will be more better and stable as below, the biggest difference is: x0 in original function will never be negative, but x1 in new function can be any value:
Root of Mean Square Error (RMSE): 7.55037962863218E-8
Sum of Squared Residual: 1.42520581341159E-13
Correlation Coef. (R): 0.886423351349966
R-Square: 0.785746357818505
Parameter Best Estimate
---------- -------------
y0 3.84276923298628E-7
x1 -2.23082444717647E24
v 10.629499809373
3 Comments
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_839650
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_839650
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_839655
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_839655
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_840389
Direct link to this comment
https://au.mathworks.com/matlabcentral/answers/522452-curve-fitting-toolbox-for-y-y0-exp-x0-x-v-where-data-is-known-but-y0-x0-and-v-are-unknown-consta#comment_840389
Sign in to comment.