Entering edit mode
3.8 years ago
DareDevil
★
4.3k
in the limma user manual, page 41-43
it provides two ways of calculation of DEGs
Approach1
#Differentially expressed genes can be found by
> fit <- lmFit(eset, design)
> fit <- eBayes(fit)
> topTable(fit, coef="Grp1vsGrp2", adjust="BH")
Approach 2;
#Differentially expressed genes can be found by
> fit <- lmFit(eset, design)
> cont.matrix <- makeContrasts(Grp1vsGrp2=Grp1 - Grp2, levels=design)
> fit2 <- contrasts.fit(fit, cont.matrix)
> fit2 <- eBayes(fit2)
> topTable(fit2, adjust="BH")
But I get different output for these methods:
Approcah1: output
ID logFC AveExpr t P.Value adj.P.Val B
1 GE_BrightCorner 14.034775 14.142391 48.329231 1.062840e-06 5.771813e-06 5.9423764
2 DarkCorner 3.526284 3.681083 11.510530 3.202467e-04 4.538190e-04 1.0973086
3 DarkCorner 4.438930 4.005311 24.177036 1.695687e-05 4.254662e-05 4.0948249
4 A_23_P117082 12.930345 12.460447 67.487497 2.788662e-07 4.420224e-06 6.4346613
5 A_33_P3246448 4.475369 4.365248 24.873738 1.514011e-05 3.896822e-05 4.1925378
6 A_33_P3318220 4.395836 4.075980 22.628496 2.207786e-05 5.232768e-05 3.8608390
7 A_33_P3236322 4.103927 4.176582 23.902379 1.774740e-05 4.407702e-05 4.0550613
Approach 2: output
ID logFC AveExpr t P.Value adj.P.Val B
1 GE_BrightCorner -0.21523164 14.142391 -0.52407752 0.627849111 0.8757925 -6.501968
2 DarkCorner -0.30959707 3.681083 -0.71459481 0.514243534 0.8245442 -6.370012
3 DarkCorner 0.86723802 4.005311 3.34001263 0.028713468 0.3393645 -3.441232
4 A_23_P117082 0.93979506 12.460447 3.46841753 0.025505731 0.3271261 -3.309127
5 A_33_P3246448 0.22024196 4.365248 0.86556019 0.435430560 0.7847096 -6.243565
6 A_33_P3318220 0.63971250 4.075980 2.32854199 0.080197184 0.4662019 -4.575855
Expect AveExpr
all other parameters are different