I am struggling with likely a simple problem, but I can't get it to work... I would appreciate if one of the more knowledgeable people could provide some code/directions to get it working...

Thanks, Guido

I have a data frame consisting of human Entrez IDs, which I would like to convert into Gene Symbols. NAs should preferably be removed. How to best do this? the select() function only accepts a character vector... (as expected).

> library(org.Hs.eg.db)

> myGenes[1:3,1:15]
     V1   V2    V3   V4   V5    V6   V7  V8  V9  V10  V11  V12  V13 V14  V15
1  1572 1571  4129  216  316   217   15 3620 7453  847 3028 1573 1576  38 3033
2 51478 3295  3294 3293 3284  3292 3283 2165 1586 1369   NA   NA   NA  NA   NA
3    10 6799 54600 6817 1544 54657   NA   NA   NA   NA   NA   NA   NA  NA   NA
> class(myGenes)
[1] "data.frame"
> anno.result <- select(org.Hs.eg.db, keys=myGenes, columns=c("SYMBOL"),keytype="ENTREZID")
Error in .testForValidKeys(x, keys, keytype, fks) :
  'keys' must be a character vector
>

It's just a matter of coercion, isn't it?

> myGenes <- data.frame(matrix(c(1572, 1571, 4129, NA, 216, 217, 15, 3620, 7453,NA), 2))
> myGenes
    X1   X2  X3   X4   X5
1 1572 4129 216   15 7453
2 1571   NA 217 3620   NA

> myGenes2 <- data.frame(matrix(mapIds(org.Hs.eg.db, as.character(unlist(myGenes)), "SYMBOL","ENTREZID"), 2))
'select()' returned 1:1 mapping between keys and columns
> myGenes2
      X1   X2      X3    X4   X5
1 CYP2F1 MAOB ALDH1A1 AANAT WARS
2 CYP2E1 NULL   ALDH2  IDO1 NULL

Or do I misunderstand what you want to end up with?

Not the prettiest sight, but a coercion to a matrix followed by a coercion to a character vector should work:

anno.result <- select(org.Hs.eg.db, keys=as.character(as.matrix(myGenes)), 
    columns="SYMBOL", keytype="ENTREZID")
anno.result <- anno.result[!is.na(anno.result$ENTREZID),]

You could also use unlist instead of as.matrix, if you want to make the code a bit more exciting.

I like using the package mygene and function getgenes().

here is my suggestion

library(mygene) #vector with genes ids

genes <- c(1572, 1571,  4129,  216,  316,   217,   15, 3620, 7453,  847, 3028, 1573, 1576,  38, 3033)

#retrieve gene information

result <- getGenes(geneid = genes,         fields = c("symbol"))

class(result)

#symbols from genes

result$symbol​