tximport
(Package: tximport) :
Import transcript-level abundances and estimated counts for gene-level analysis packages
tximport imports transcript-level estimates from various external software and optionally summarizes abundances, counts, and transcript lengths to the gene-level (default) or outputs transcript-level matrices (see txOut argument). While tximport summarizes to the gene-level by default, the user can also perform the import and summarization steps manually, by specifing txOut=TRUE and then using the function summarizeToGene. Note however that this is equivalent to tximport with txOut=FALSE (the default).
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