Message-ID: <000101d3cb30$27b246a0$7716d3e0$@tpg.com.au>
Date: 2018-04-03T09:42:57Z
From: Ahmad
Subject: adding a constant to a continuous dataset with zero values- to use the log transformation
Hi all
My question here is related to my previous query on Geometric mean of log
data.
I have a continuous dataset with considerable number of zero values, and
not-normally distributed. Because of zero values, I won't be able to take
the log of this variable. It has been suggested by some to add a constant
(e.g. +1) to all data to be able to take the log of data. I can then
transform back the output of lm() or Mixed-model to the original scale using
exp() or emmeans function with "response" method as suggested by Russell
(russell-lenth at uiowa.edu).
I searched this (adding a constant) and found that views on this approach
are not consistent- I would like to see if anyone has experience on how to
deal with such data.
Your help is greatly appreciated!
Ahmad