Where datExpr come from: ''' powerEstimate <- as.numeric(sft$powerEstimate) datExpr <- lapply(datExpr, as.numeric) datExpr <- do.call(cbind, datExpr)

''' Code: ''' TOM <- TOMsimilarityFromExpr(datExpr, power = sft$powerEstimate)

''' Result:

1 NaN NaN

NaN 1 NaN
NaN NaN. 1

WGCNA is not a Bioconductor package, please ask at biostars.org or StackExchange Bioinformatics, but if you do make this a good question. A good question has example data, code, software versions and markdown highlighting.