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st: RE: unpaired regression


From   "Scott Merryman" <[email protected]>
To   <[email protected]>
Subject   st: RE: unpaired regression
Date   Mon, 10 May 2004 20:41:46 -0500

How about lining up the measurements?

Something like

. l

     +-------------------------+
     | batch   assay1   assay2 |
     |-------------------------|
  1. | Btch1     5400        . |
  2. | Btch1     5320        . |
  3. | Btch1     5670        . |
  4. | Btch1        .       .9 |
  5. | Btch1        .     .905 |
     |-------------------------|
  6. | Btch1        .     .898 |
  7. | Btch2     8600        . |
  8. | Btch2     7840        . |
  9. | Btch2     7550        . |
 10. | Btch2        .     .962 |
     |-------------------------|
 11. | Btch2        .     .955 |
 12. | Btch2        .     .943 |
     +-------------------------+

. by batch: replace assay2 = assay2[_n +3]
(12 real changes made, 6 to missing)

. drop if assay1 == .
(6 observations deleted)

. l

     +-------------------------+
     | batch   assay1   assay2 |
     |-------------------------|
  1. | Btch1     5400       .9 |
  2. | Btch1     5320     .905 |
  3. | Btch1     5670     .898 |
  4. | Btch2     8600     .962 |
  5. | Btch2     7840     .955 |
     |-------------------------|
  6. | Btch2     7550     .943 |
     +-------------------------+


Scott

________________________________________
From: [email protected]
[mailto:[email protected]] On Behalf Of Wallace, John
Sent: Monday, May 10, 2004 7:48 PM
To: '[email protected]'
Subject: st: unpaired regression

I have two measures of batch performance on which I'd like to perform a
regression.� The measurements are taken on separate samples from the batch,
and typically look something like:
����������� Assay1 Assay2
Btch1��� 5400���� ���� 
Btch1��� 5320���� ���� 
Btch1��� 5670���� ���� 
Btch1��������������� 0.900
Btch1��������������� 0.905
Btch1��������������� 0.898
Btch2��� 8600���� ���� 
Btch2��� 7840���� ���� 
Btch2��� 7550���� ��� 
Btch2��������������� 0.962
Btch2��������������� 0.955
Btch2��������������� 0.943
...etc (on for multiple batches which show correlated measures for the two
assays)
-collapse- ing them to batch averages and then performing the regression is
one approach, but it doesn't take variance of the measures themselves into
account in the regression.� Is there a system for performing this type of
analysis?
�
Thanks,
John Wallace�|�Research Associate�| Test Method Development
AFFYMETRIX, INC. | 3380 Central Expressway | Santa Clara, CA 95051 | Tel:�
408-731-5574 | Fax:� 408-481-0435
�


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