Hi

Thank you for your reply. That was helpful.

I tried changing the constrain into Y0 equal constant=0 and it was solved. however, i know the value for the plateau and K will be slightly different (I tried it on another data set with and without constrain).

Hi there,

I am not sure what exact testing you are trying to achieve. However, if you are having issues with data spread it is acceptable to log transform your data for analysis. This will aid in problems of normality and equal variance spread.

Hi Lewis

I am testing a flow over time. Using one phase association fit.

Could you detail this more, if I were to transform data, which function I should select.

Thanks in advance