How can I identify parameters of a nonlinear implicit function?

I write the function in the form of f(x,y)=0, make x,y as input and 0 as output, then employ nlinfit. But the result is poor. Is there any better way to do that?

Answer 1

[Shashank Prasanna]

Fan you will need to provide more information.

What do you mean by poor results? Can you provide f(x,y) this will be really helpful.

There are limitations based on how f(x,y) looks and we can suggest alternate approaches based on that.

[Fan]

I'm sorry, Here is it again:

Thank you, Benji! You just answered both my questions!

f(x,y)=0 is like:

c1-y-(x+c4*y)/c3-c4*(e^((x+c4*y)/0.026)-1)=0

%c1 c2 c3 c4 are the parameters that will be identified

%x is independent variable and y is dependent variable, which are derived by experiment

Answer 2

[Fan]

Thank you, Benji! You just answered both my questions!

f(x,y)=0 is like:

c1-y-(x+c4*y)/c3-c4*(e^((x+c4*y)/0.026)-1)=0

%c1 c2 c3 c4 are the parameters that will be identified

%x is independent variable and y is dependent variable, which are derived by experiment

[Shashank Prasanna]

Fan to reply to my answer use the comment box above so that we can maintain discussion there, this way, if this answer is useful to you can mark it as accepted answer. The answer box is used for others to throw ideas and help you with the question.