Model 'locked' to first point value
I'm studying a decay process as shown for a number of samples below. The higher the starting point, the faster the decay. The idea is to predict the value at any timeopint from measured Initial value. I would like to 'lock' the model so that at timepoint zero, the predicted value is exactly the measured Initial value. If not, predictions as short time times can be very off for some samples, as in ...