[R] Linear multivariate regression with Robust error

[Barjesh Kochar]

Dear all,

i am doing linear regression with robust error  to know the effect of
a  (x) variable on (y)other if i execute the command i found positive
trend.
         But if i check the effect of number of (x.x1,x2,x3)variables
on same (y)variable then the positive effect shwon by x variable turns
to negative. so plz help me in this situation.

Barjesh Kochar
Research scholar