Hi All,

I am trying to analyze my Force spectroscopy data. I need to fit a function that contains an exponential integral function over my loading rate-rupture force data points. The form of the function is basically:

y =b + a exp (z) E1 (z)

Based on what I have read so far I know that for solving it, we can approximate exp(z) E1(z) to be ln(1+exp (-0.5777)/z). But I need to graph the initial function in order to fit it into my data points.

https://en.wikipedia.org/wiki/Exponential_integral

eq9 in Article Interpreting the widespread nonlinear force spectra of inter...

I will appreciate any suggestions/guidance for plotting an exponential integral function (either in excel or any other software).

Thank you,

Mina