conversion of non parametric values to parametric ones


New Member
Dear all :) ,
I'm doing a biological research on vegetative propagation of tree species 'A'. As observations I get both parametric (eg: root biomass) and non-parametric measures (eg:number of new leaves developed). In the data analysis, I have to convert non-parametric values to parametric ones.But when doing this conversion using natural logarithm (on an Excel sheet) zero values remain zero while '1' become zero. Unfortunately as readings for my 'number of new leaves developed' i have got loads of zeros, few 1s and very few numbers greater than 1.So after conversion I rarely get any value but Zero.
I want to know if there is a way I can get a value for non-parametric '1' after converting it to a parametric value.
Thank you very much!!!!!


Omega Contributor
You can add a constant to all of the numbers before transforming them (e.g., 3). Or I think there may be Heckman style procedures that can be used.