https://www.jianshu.com/p/6a364dc7bd03
# https://www.bioinfo-scrounger.com/archives/342/ library(GenomicFeatures) txdb <- makeTxDbFromGFF("resources/genome.gtf",format="gtf") exons_gene <- exonsBy(txdb, by = "gene") exons_gene_lens <- lapply(exons_gene,function(x){sum(width(reduce(x)))}) saveRDS(exons_gene_lens,file="exons_gene_lens.rds")