TITLE `Norm' module to normalize variables DESCRIPTION/AUTHOR(S) Norm module generates normalize variables using z-score, min-max, softmax and sigmoid techniques. The module supports multiple variables and panel dataset. KW: Normalize KW: Z-score KW: Min-Max KW: Softmax KW: Sigmoid Authors: Muhammad Rashid Ansari, INSEAD Business School Support: email rashid.ansari@insead.edu Chiara Mussida, Università Cattolica del Sacro Cuore Support: email chiara.mussida@unicatt.it Requires: Stata version 9 Distribution-Date: 20130917 *Version September 2013 ------------------------- TITLE 'norm': module to normalize variable basic syntax: norm var, by(varlist) method(#) [if in] Description: Norm module generates normalize variables using z-score, min-max, softmax and sigmoid techniques. The module supports multiple variables and panel dataset. Options: zee :calculates normalize score also called z-score. mmx :calculates normalize scores using minimum & maximum observations softmax :calculates normalize score using exponential function and mean and standard deviation. sigmoid :calculates normalize score using double sigmoid function by(varlist): allows multiple groups defined by `varlist' ---------------------- Standardized Z-score ---------------------- Zee= Xi- X(mean)/ sigma where, X(mean)=group average sigma =standard deviation -------------------- Min-Max Normalization -------------------- mmx= [Xi - X(min)]/ [X(max)-X(min)] where, X(mins)=minimum data point X(max) =maximum data point mmx=normalize score ranges between 0 & 1 --------------------- Softmax Normalization --------------------- softmax= 1 / 1+exp^(-V) where, V =[Xi-(x)mean)]/sigma sigma =standard deviation --------------------- Sigmoid Normalization --------------------- softmax= 1-exp^(-V) / 1+exp^(-V) where, V=[Xi-(x)mean)]/sigma sigma = standard deviation Examples: ---------- norm x1 x2 x3, by(year) method(zee) norm x1 x2 x3, by(year) method(mmx) norm x1 x2 x3, by(year) method(softmax) norm x1 x2 x3, by(year) method(sigmoid) Authors: Muhammad Rashid Ansari INSEAD Business School 1 Ayer Rajah Avenue, Singapore 138676 rashid.ansari@insead.edu Chiara Mussida Università Cattolica del Sacro Cuore vai Emilia Parmense, 84, 29122 Piacenza, Italy chiara.mussida@unicatt.it