[BioC] Limma: can't coerce Rgmodel into exprSet

[michael watson (IAH-C)]

Hi

I have a kooperberg bg corrected dataset in limma and I want to coerce
it to an exprSet object so that I can do some other stuff with it.  I
have two objects, RG which is a normal RG object, and RGmodel which is
the kooperberg one:

> as(RG, "exprSet")
An object of class "exprSet2"
@expressions
     EXP1_NC_Cy3-DETANO_Cy5 EXP1_NC_Cy5-DETANO_Cy3
EXP2_NC_Cy3-DETANO_Cy5 EXP2_NC_Cy5-DETANO_Cy3
[1,]                  36551                  43598
61149                  36924
[2,]                   1404                   1168
914                    960
[3,]                   2879                   2222
3844                   4283
[4,]                  16497                  11104
812                   9903
[5,]                   4500                   3207
852                   8055
     EXP1_NC_Cy3-DETANO_Cy5 EXP1_NC_Cy5-DETANO_Cy3
EXP2_NC_Cy3-DETANO_Cy5 EXP2_NC_Cy5-DETANO_Cy3
[1,]                    519                    450
360                    388
[2,]                    432                    454
286                    298
[3,]                   3407                   1252
7398                   1844
[4,]                  18128                   6515
273                   6913
[5,]                   4337                   1621
295                   5100
4619 more rows ...

@probes
  Block Row Column              ID Name
1     1   1      1 Cy3 lights (12A     
2     1   1      2 Carry-over 16s      
3     1   1      3  5s rRNA (11I4)     
4     1   1      4 16s rRNA N (11E     
5     1   1      5 16s rRNA 1:3 (1     
4619 more rows ...

> as(RGmodel, "exprSet")
Error in as(RGmodel, "exprSet") : No method or default for coercing
"list" to "exprSet"


As can be seen, the RG object happily goes to an exprSet object, but the
RGmodel one refuses.  I guess this is because the RGmodel has no values
for background intensity??

Thanks

Mick