Thanks! This is just what I need. Not having any luck with performing the same KEGG conversion though. would you know what I am doing wrong here?
kegg_list <- mapIds(org.Mm.eg.db, keys(org.Mm.eg.db, "KEGG"),
"ENTREZID", "KEGG", multiVals = "list")
Error in testForValidKeytype(x, keytype) :
Invalid keytype: KEGG. Please use the keytypes method to see a listing of valid arguments.
OK, so you made a wild guess that the keytype for KeGG is 'KEGG', which is fine. But then you get an error and more importantly a message telling you how to get the available choices!
Two points to keep in mind. First, for most scripting languages and Open Source software in general, the help you get tends to be pretty terse. Which isn't to say unhelpful. Usually everything you need is there, you just have to pay attention to what is offered. Second, if you plan to use R, like at all, you need to learn how to figure things out for yourself. It's OK to ask questions, but that should be the last thing you do, after you have tried to figure things out yourself and have failed. So in the spirit of my second point, here's how you could proceed.
You got a message telling you what to do. So let's do it:
How did I know that's how to use keytypes? By doing ?keytypes to get the help page, as one does. But this isn't super helpful, because there's not anything like KeGG in that list. So, other alternatives. You could do ?org.Mm.eg.db but that just brings up a generic page about the package. You could see what functions are in the package (super useful thing to do, btw), by doing something like
> search()
[1] ".GlobalEnv" "package:org.Mm.eg.db" "package:AnnotationDbi"
[4] "package:IRanges" "package:S4Vectors" "package:Biobase"
[7] "package:BiocGenerics" "package:parallel" "package:stats4"
[10] "package:BiocManager" "ESSR" "package:stats"
[13] "package:graphics" "package:grDevices" "package:utils"
[16] "package:datasets" "package:methods" "Autoloads"
[19] "package:base"
## which indicates that the org.Mm.eg.db package is second in the search path.
## since I've been around for a while, I know about the ls() function, so here's a legit hint
> ls(2)
[1] "org.Mm.eg" "org.Mm.eg.db"
[3] "org.Mm.eg_dbconn" "org.Mm.eg_dbfile"
[5] "org.Mm.eg_dbInfo" "org.Mm.eg_dbschema"
[7] "org.Mm.egACCNUM" "org.Mm.egACCNUM2EG"
[9] "org.Mm.egALIAS2EG" "org.Mm.egCHR"
[11] "org.Mm.egCHRLENGTHS" "org.Mm.egCHRLOC"
[13] "org.Mm.egCHRLOCEND" "org.Mm.egENSEMBL"
[15] "org.Mm.egENSEMBL2EG" "org.Mm.egENSEMBLPROT"
[17] "org.Mm.egENSEMBLPROT2EG" "org.Mm.egENSEMBLTRANS"
[19] "org.Mm.egENSEMBLTRANS2EG" "org.Mm.egENZYME"
[21] "org.Mm.egENZYME2EG" "org.Mm.egGENENAME"
[23] "org.Mm.egGO" "org.Mm.egGO2ALLEGS"
[25] "org.Mm.egGO2EG" "org.Mm.egMAPCOUNTS"
[27] "org.Mm.egMGI" "org.Mm.egMGI2EG"
[29] "org.Mm.egORGANISM" "org.Mm.egPATH"
[31] "org.Mm.egPATH2EG" "org.Mm.egPFAM"
[33] "org.Mm.egPMID" "org.Mm.egPMID2EG"
[35] "org.Mm.egPROSITE" "org.Mm.egREFSEQ"
[37] "org.Mm.egREFSEQ2EG" "org.Mm.egSYMBOL"
[39] "org.Mm.egSYMBOL2EG" "org.Mm.egUNIGENE"
[41] "org.Mm.egUNIGENE2EG" "org.Mm.egUNIPROT"
And then you can look at the help pages for any of those functions, like ?org.Mm.eg.SYMBOL or whatever, and you will see that the help page says it maps between Entrez Gene IDs and MGI symbols. So if you then went through all the likely subjects (because for sure UNIGENE and REFSEQ and UNIPROT aren't candidates), you end up with ?org.Mm.egPATH which says
org.Mm.egPATH package:org.Mm.eg.db R Documentation
Mappings between Entrez Gene identifiers and KEGG pathway identifiers
Description:
KEGG (Kyoto Encyclopedia of Genes and Genomes) maintains pathway
data for various organisms. org.Mm.egPATH maps entrez gene
identifiers to the identifiers used by KEGG for pathways
I should note however that these KeGG mappings are pretty old now, because the data have been put behind a paywall. You can however get data using the KEGGREST package. Which has a vignette you can read to get up to speed.
Thanks! This is just what I need. Not having any luck with performing the same KEGG conversion though. would you know what I am doing wrong here?
OK, so you made a wild guess that the keytype for KeGG is 'KEGG', which is fine. But then you get an error and more importantly a message telling you how to get the available choices!
Two points to keep in mind. First, for most scripting languages and Open Source software in general, the help you get tends to be pretty terse. Which isn't to say unhelpful. Usually everything you need is there, you just have to pay attention to what is offered. Second, if you plan to use R, like at all, you need to learn how to figure things out for yourself. It's OK to ask questions, but that should be the last thing you do, after you have tried to figure things out yourself and have failed. So in the spirit of my second point, here's how you could proceed.
You got a message telling you what to do. So let's do it:
How did I know that's how to use
keytypes? By doing?keytypesto get the help page, as one does. But this isn't super helpful, because there's not anything like KeGG in that list. So, other alternatives. You could do?org.Mm.eg.dbbut that just brings up a generic page about the package. You could see what functions are in the package (super useful thing to do, btw), by doing something likeAnd then you can look at the help pages for any of those functions, like
?org.Mm.eg.SYMBOLor whatever, and you will see that the help page says it maps between Entrez Gene IDs and MGI symbols. So if you then went through all the likely subjects (because for sure UNIGENE and REFSEQ and UNIPROT aren't candidates), you end up with?org.Mm.egPATHwhich saysAnd then you have helped yourself.
I should note however that these KeGG mappings are pretty old now, because the data have been put behind a paywall. You can however get data using the KEGGREST package. Which has a vignette you can read to get up to speed.