[BioC] rlm function

[SERGI VIVES CIVIT]

Hi,
I'm trying to use rlm function in an unequally replicated 2x3 factorial 
experiment all
combinations of 3 temperatures by 2 amounts.(cDNA microarrays)

For each gene I have 6 log ratios,
and can do a standard factorial experiment analysis, giving a grand
mean, a main effect of amount, and 2 degrees of
freedom for the main effect of temperature, a linear effect and a quadratic 
effect, 
These are the main effects, and the two
degrees of freedom interaction effects, see matrix below.

Here is a little matrix of coefficients for all these terms.

                            
mean                   +     +     +     +     +     +
amount                 -     +     -     +     -     +
linear temp            -     -     0     0     +     +
amount temp            +     +    -2    -2     +     +
amount.linear          +     -     0     0     -     +
amount.quad            -     +     2    -2     -     +

This becomes and orthogonal transformation of the 6 observations by
normalizing the rows appropriately.

Could you please suggest me how to include this matrix design into rlm function?

Thanks in advance.
SV