Double-exp model with built-in classes

[matteogabba]

Hey Do,

I am trying to implement a double exponential decay model using the built in classes but I am having some troubles implementing the amplitude fraction x1.
Is that even possible using the built in classes?
Do you have any suggestion?

This is the model:

f(t) = a * [ x1 * exp(-k1t) + (1 - x1) * exp(-k2t) ]

Cheers,

Matteo

[dokester]

I would suggest to rewrite the double decay model somewhat as

f(t) = alfa * exp( -k1 t ) + beta * exp( -k2 t )

A little mathematics will show that this is the same as your f(t) when

a = alfa + beta
x1 = alfa / ( alfa + beta )

Now there is no relation between the parameters of the 2 ExpModels

Do.