Z(x)=(50*m+m^2*tanh((a+b*i)*x))/(m+50*tanh((a+b*i)*x))(adsbygoogle = window.adsbygoogle || []).push({});

where i is imaginary unit, x is the independent variable, Z is the dependent variable, and a, b and m are the parameters.

We measures variable Z at a discrete set of values of variable x:

x=[1, 2, 3, 4, ...20]

Z=[57.6286+0.6328*i, 57.1207+0.6694*i, 56.9751+0.6525*i, 58.4018+0.6432*i, 57.2407+0.6809*i, 57.4864+0.6892*i, 58.7988+0.6761*i, 59.6706+0.7166*i, 58.5738+0.6758*i, 59.1651+0.6283*i, 58.4831+0.6437*i, 59.6807+0.6949*i, 58.6072+0.6453*i, 58.5499+0.6452*i, 60.0737+0.7014*i, 59.3941+0.6916*i, 58.7153+0.7090*i, 58.5133+0.6446*i, 60.8528+0.6817*i, 60.7193+0.6810*i]

We want to know what parameter values of a, b and m correspond to the data.

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# How to fit a complex equation?

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