[Help-gsl] Nonlinea fitting with exit info = 27

[Jiawei Zhao Zhao]

Dear GSL mailing list.


I am new to GSL and trying to fit a Non linear function. the function is given 
below.


y = A*( ( b / (x-r0) ) ^ m- B* ( b / (x-r0) ) ^ n)


I modified an example of non linear fitting (code attached). The function 
successfully complied  and first deviation gives correct value.


However, when I test with generating data from:


A=1, b= 2.5, m=12, n=6, r0=0 and B=1


and try to fit it start from


A=1, b= 2.4, m=12, n=6, r0=0 and B=1


The iteration seems stopped at the first steps with info = 27.


Can anyone help me on this?


Regards.


Jiawei Zhao

main.c
Description: main.c