Message-ID: <1358172288.42909.YahooMailNeo@web160702.mail.bf1.yahoo.com>
Date: 2013-01-14T14:04:48Z
From: Andre Cesta
Subject: How to fit a linear model to data by minimizing the mean absolute percent error?
Hi All, I wonder if you can help me with an aparently simple task. ?I have been searching examples for this without any luck: #Assume
x<-1:10 ?#x ranges from 1 to 10.
y<-x*runif(10)+ 1.5*x ?#y is a linear function of x with some error. Add uniform error that is scaled to be larger as x values also become larger #error is proportional to x size, this should cause heterocedasticity. #I know there are many methods to deal with heterocedasticity, but in my specific case,?I want to use percent regression to minimize the mean absolute?
#percentual error as opposed to regular regression that deals with the square of the errors. #Question, how to fit a linear model to minimize this error on the data y ~ x above?
#Please do not use model<-lm(y ~ x....) as this will minimize the square of the errors, not the mean absolute percent error Best regards, Andr? Cesta