gets gene symbols for all ensembl gene ids

ensembl_to_all_symbols.R

library(dplyr)
library(AnnotationDbi)
library(org.Mm.eg.db)
ls("package:org.Mm.eg.db")

entrez2alias <- org.Mm.egALIAS2EG %>%
  as.list %>%
  unlist %>%
  data_frame(entrez=., alias=names(.))
head(entrez2alias)

entrez2ensembl <- org.Mm.egENSEMBL2EG %>%
  as.list %>%
  unlist %>%
  data_frame(entrez=., ensembl=names(.))
head(entrez2ensembl)

ensembl2allsymbols <- entrez2ensembl %>%
  inner_join(entrez2alias, by="entrez") %>%
  select(ensembl, alias) %>%
  distinct %>%
  na.omit %>%
  arrange(ensembl, alias)
nrow(ensembl2allsymbols)
head(ensembl2allsymbols)