[BioC] simpleaffy function detection.p.value (and affy function
mas5call s?)
Christian.Stratowa at vie.boehringer-ingelheim.com
Christian.Stratowa at vie.boehringer-ingelheim.com
Fri Mar 11 14:06:07 CET 2005
Dear BioC people
Comparing the output from simpleaffy with the Affymetrix MAS5 software we
have found the following inconsistency:
Output MAS5:
MAS5 Signal Detection Detection p-value
1005_at 80139.8 P 0.000219
1081_at 24695.2 P 0.000219
AFFX-BioB-3_at 12714.9 P 0.00011
AFFX-BioB-M_at 21123.8 P 0.000044
AFFX-BioC-3_at 19104.8 P 0.000052
AFFX-BioC-5_at 22924.5 P 0.000095
AFFX-BioDn-3_at 124659.3 P 0.000081
Output from simpleaffy (combining output from functions call.exprs and
detection.p.value):
BioC Signal Detection Detection p-value
1005_at 80197.83231 P 0.000218932
1081_at 24713.12704 P 0.000218932
AFFX-BioB-3_at 12724.08753 P 0.00010957
AFFX-BioB-M_at 21139.08669 A 4.43E-05
AFFX-BioC-3_at 19118.62503 A 5.17E-05
AFFX-BioC-5_at 22941.10276 A 9.45E-05
AFFX-BioDn-3_at 124749.6972 A 8.15E-05
Comparing the two tables you see that simpleaffy gives an Absent call
whenever the detection p-vaule is of type "n.nE-0x"
Could it be that in function detection.p.value the statement:
calls <- sapply(p, function(y)...
should be replaced with:
calls <- sapply(as.double(p), function(y)...
For your info:
We are using R-2.0.1 and simpleaffy_2.01 on an 64bit Opteron Machine with
RedHat Enterprise 3.0
Thank you in advance for your help
Best regards
Christian Stratowa
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