user defined equation fit to a dat a set

I have x axis values=x

 y axis values=y

and equation of line to be fit on the plot of data is suppose

d=a*exp(x^b - 2^b)

where a and b i have to find...

so please help me out with this problem

Answer 1

[AJ von Alt]

The fit function can use custom non-linear models. The custom nonlinear models article gives an example of how to do this from the command line.

For your model it would be:

    f = fit( x , y ,'a*exp(x^b-2^b)')

[aditi]

hey von

I tried using it...but i am getting 'a' value suppose 1 which actually should come 5 and am getting 'b' value suppose 1...it should actually be 2...

 so m getting very less values than the correct one...