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Performs differential expression analysis using the limma package to identify significantly expressed genes across different cell types. Computes median expression levels of these significant genes to create a reference signature matrix.

Usage

generateRef_limma(dat, pheno, FDR = 0.05)

Arguments

dat

Matrix or data frame. Gene probes in rows and samples in columns.

pheno

Character vector. Cell type class of the samples.

FDR

Numeric. Genes with BH adjusted p-value < FDR are considered significant. Default is 0.05.

Value

List containing: - `reference_matrix`: Data frame of median expression values for significantly expressed genes. - `G`: Number of probes used that resulted in the lowest condition number. - `condition_number`: Minimum condition number obtained. - `whole_matrix`: Matrix of median values across all samples.

Examples

dat <- matrix(rnorm(2000), nrow = 100)
rownames(dat) <- paste("Gene", 1:100, sep = "_")
colnames(dat) <- paste("Sample", 1:20, sep = "_")
pheno <- sample(c("Type1", "Type2", "Type3"), 20, replace = TRUE)
results <- generateRef_limma(dat, pheno)
print(results)
#> $reference_matrix
#> [1] Type1 Type2 Type3
#> <0 rows> (or 0-length row.names)
#> 
#> $G
#> [1] 50
#> 
#> $condition_number
#> [1] 0
#> 
#> $whole_matrix
#>                  Type1        Type2        Type3
#> Gene_1   -3.502960e-01 -0.069601836 -0.370146624
#> Gene_2    2.685985e-01  0.059208651  0.075836973
#> Gene_3   -8.763115e-01  0.312058303 -0.152545773
#> Gene_4   -3.549884e-01  0.179047539 -0.020622229
#> Gene_5   -2.320709e-01 -0.262678090  0.330602226
#> Gene_6    1.151466e-01 -0.602030747 -1.069252172
#> Gene_7    6.541015e-02  0.117420548 -0.227624806
#> Gene_8    2.727289e-01  0.703001795 -0.275899218
#> Gene_9    5.683064e-01 -0.005087181 -0.729808806
#> Gene_10   4.594009e-01 -0.779880243  0.533685008
#> Gene_11  -5.502303e-01  0.385040501 -0.424865175
#> Gene_12   1.720136e-03  0.351996769 -0.158058937
#> Gene_13  -3.402926e-01 -0.168059235 -0.178463862
#> Gene_14  -5.161753e-01  0.045993767 -0.524372043
#> Gene_15   5.266697e-03  0.417240224  0.111038368
#> Gene_16  -5.908702e-01  0.020477665 -0.134347986
#> Gene_17  -3.329544e-01  0.595069071 -0.577898941
#> Gene_18  -5.192909e-01  0.123993539  0.371894882
#> Gene_19  -6.767065e-01 -0.106397594  0.623540463
#> Gene_20   4.611238e-01 -0.059918201  0.278374002
#> Gene_21   2.031379e-01  1.284800815 -0.134612834
#> Gene_22   5.215295e-01 -0.109079876  0.055944426
#> Gene_23  -1.598989e-01 -0.994479836 -0.004844437
#> Gene_24  -4.602964e-01 -0.199867235  0.406366471
#> Gene_25   2.587356e-01  0.753420372  0.928280305
#> Gene_26   5.928206e-01  0.435595444  0.125964082
#> Gene_27  -6.403511e-01  0.220506660 -0.106292769
#> Gene_28   2.167055e-01  0.150213368 -0.122163599
#> Gene_29   2.977136e-01 -0.012546975  0.157479548
#> Gene_30  -8.557442e-01  0.671853873  0.077342903
#> Gene_31  -5.353458e-01  0.601359844  0.093822156
#> Gene_32   6.124180e-01  0.054609574 -0.422872007
#> Gene_33   3.171691e-01  0.236595502  0.136823619
#> Gene_34  -4.838731e-01 -0.044471920  0.013903658
#> Gene_35   1.547656e-01 -0.534811163 -0.137579581
#> Gene_36  -9.190144e-01 -0.031219996  0.264011434
#> Gene_37  -2.486837e-01 -0.425911201  0.091283554
#> Gene_38   2.080257e-01  0.180822011 -0.404069682
#> Gene_39  -3.888222e-05 -0.560241851 -0.099720369
#> Gene_40   6.725611e-02 -0.571339759  0.219787376
#> Gene_41   7.290482e-01  0.373684804  0.482758609
#> Gene_42   3.451223e-01  0.735091630  0.168024801
#> Gene_43   2.231167e-01  0.057850704 -0.913005531
#> Gene_44  -3.140320e-02 -0.262894843 -0.175058128
#> Gene_45  -8.333821e-01 -0.294231849 -0.579026453
#> Gene_46   1.067362e-03 -0.339967488 -0.022015036
#> Gene_47  -3.766091e-01  0.618532252 -0.121476365
#> Gene_48  -2.066444e-01  0.402639185 -0.773844310
#> Gene_49   2.477232e-01  0.877530984  0.329200588
#> Gene_50  -3.987424e-01 -0.464882765  0.281819311
#> Gene_51   3.578568e-01 -0.836164804 -0.172836903
#> Gene_52   5.901957e-01  0.214424249  0.254068220
#> Gene_53  -1.104618e-01  0.305685156  0.890379626
#> Gene_54  -3.022576e-01 -1.183133966 -0.666705010
#> Gene_55  -1.831076e-01 -0.780501609 -0.677023065
#> Gene_56   1.277111e-01  0.219747430  0.010664862
#> Gene_57   1.160399e-01  0.629521384 -0.525321835
#> Gene_58  -3.635230e-01 -0.300852632 -0.213349406
#> Gene_59  -2.930877e-01 -0.636273494  0.253270150
#> Gene_60  -3.325496e-01 -0.645806382 -0.093001089
#> Gene_61  -1.139282e+00 -0.131307112 -0.229254725
#> Gene_62   3.263049e-01  0.042513309  0.103362815
#> Gene_63   5.574303e-01 -0.015876540 -0.161248545
#> Gene_64  -9.888091e-01 -0.631445134 -0.085891551
#> Gene_65  -2.460990e-01 -0.231484945 -0.421548024
#> Gene_66   7.858191e-01 -0.548731015 -0.491443047
#> Gene_67  -1.781785e-01 -0.468696015  0.545635528
#> Gene_68   3.561357e-01 -0.284903482 -0.288449296
#> Gene_69  -2.333460e-01  0.356334108  0.710110232
#> Gene_70  -3.170696e-01 -0.081589880  0.633333596
#> Gene_71  -2.284047e-01 -0.732566487 -0.010768077
#> Gene_72  -6.615776e-01  0.741194720  0.433158965
#> Gene_73   4.535271e-01  0.461566094 -0.060610081
#> Gene_74   5.094687e-01 -0.200147013 -0.678807619
#> Gene_75  -3.245077e-01 -0.173451330 -0.048064173
#> Gene_76  -1.474565e-01  0.793918367 -0.587684757
#> Gene_77   6.469226e-01 -0.277366228 -0.228406204
#> Gene_78  -4.494626e-01  0.430427805 -0.130421890
#> Gene_79   9.019831e-01  0.734458203 -0.037415014
#> Gene_80   4.017629e-01 -0.213887080  0.139471133
#> Gene_81   2.941686e-01 -0.246528493 -0.184526498
#> Gene_82  -3.323693e-01  0.195664504 -0.234463431
#> Gene_83   1.875159e-01  0.390576089  0.250899226
#> Gene_84   1.476251e-02 -0.234026744  0.466728667
#> Gene_85   1.737364e-01 -0.283973587  0.244262636
#> Gene_86  -2.032521e-01 -0.263158284 -0.253966134
#> Gene_87  -6.713319e-01  0.056004304  0.734512927
#> Gene_88   4.520024e-01 -0.182194333 -0.237734026
#> Gene_89  -1.203289e-01 -0.317360284 -0.136112157
#> Gene_90   3.891164e-01 -0.384798672  0.124378266
#> Gene_91  -1.036532e+00  0.330680560  0.175396079
#> Gene_92   4.601790e-02 -0.494699035  0.420861381
#> Gene_93  -8.855479e-01  0.099308427  0.683406456
#> Gene_94   5.244652e-01 -0.635206049  0.725598608
#> Gene_95  -7.683220e-01 -0.248303831 -0.577421345
#> Gene_96   3.249445e-01  0.367501231 -0.274480218
#> Gene_97  -1.294047e+00  0.482825594  0.374320874
#> Gene_98  -7.923611e-02  0.566919054 -0.210025808
#> Gene_99   2.979372e-01  0.541704658 -0.457483759
#> Gene_100  1.284161e+00  0.172659184 -0.539746145
#>