Well whats inside the files if you open them with an editor?

I'm not sure what you actually downloaded. If these files are collected through generating an abundance table* with the Usage of the MG-RAST Analysis Tool either one should do fine.

*Taxonomic or Functional Abundance

If your not certain and really need to operate with the files you have now here is how to decide if the file is useful for stamp:

The file you need should consist of rows which are tabulator seperated. The first row should contain the metagenomic ID: 4031525.3 for example afterwards there has to be rows with your taxonomic or functional parameters you want to investigate.

The Metadata file you have to write yourself. It simple by using a text editor

First Line should contain headings tab seperated. Afterwards you list the metagenomic ID and some Metadata for grouping the metagenomes like habitat. Be sure that at least two metagenomic IDs share the same Group or else STAMP won't work properly. I could provide you a example his evening (around 17:00 EST.), if you drop me a line via email.

Regards

Robert

edit: Oh I just recently registerd to this plattform. It seems I can attach files. so here is a metadata example.:

Be sure to use the tabulator Key for the whitespace just once.

Dear Robert,

thank you for the answer. An Argentine researcher help me with this problem yesterday. I have both files now and everything is running okay. Just work with the data now.

Do you know what is the function of Metadata? One of them (metadata or profile, i don't remember) the program display that is optional, right? I think probably is important to get more accurate data.

Thank you.

Well the metadatafile is "optional" in a sense. Without the Metadatafile you are only able to compare the metagenomes individually. But to Perform a T-Test or an ANOVA they have to be assigned to groups with the metadatafile. STAMP won't work if a Group only contains one metagenome. If you want to mess around with the metadatafile, you have to restart STAMP. (Reloading only results in a Crash of STAMP).

Edit: So In short the metadatafile matters if you have more than two

metagenomes you want to compare.