anova(Terms, L...)

["Francisco Vergara" <gerifalte28@hotmail.com>]

Hi

I have an lm object with 4 parameters Beta1+Beta2+Beta3+Beta 4 and I want to 
test wether 2 parameters are equal using a Wald test (basically b1=b2 or 
b1-b2 =0).  The S-Plus help file describes that under ANOVA the optional 
arguments " Terms" or "L" test whether a linear combination is equal to 0.  
I tried;
   anova(m1, Terms = Beta1-Beta2=0) but I get the error:

Object " Beta1" must be assigned locally before replacement.

I also tried

   anova (m1, Terms = 1-2 = 0) and I get:


Invalid assginment: No object name : 1-2 = 0

What am I doing wrong? Any help will be greatly appreciated!

Thanks for your help!!

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