**Subsections**

##

relax_fit.select_model

Select the relaxation curve type.

relax_fit.select_model(model=`exp')

model: The type of relaxation curve to fit.

A number of relaxation experiments are supported and include:

The ``exp`' model. This is the default two parameter exponential fit. The magnetisation starts at I0 and decays to zero. The parameters are [Rx, I0] and the equation is I(t) = I0*exp(-Rx*t).

The ``inv`' model. This is the inversion recovery experiment (IR). The magnetisation starts at a negative value at -I0 and relaxes to a positive Iinf value. The parameters are [Rx, I0, Iinf] and the equation is I(t) = Iinf - I0*exp(-Rx*t).

The ``sat`' model. This is the saturation recovery experiment (SR). The magnetisation starts at zero and relaxes to a positive Iinf value. The parameters are [Rx, Iinf] and the equation is I(t) = Iinf*(1 - exp(-Rx*t)).

The relax user manual (PDF), created 2016-10-28.