Generate an EML file given a data.frame and appropriate metadata

[cboettig]

To begin with, consider rendering a data.frame such as this

 dat = data.frame(river=c("SAC", "SAC", "AM"), 
                   spp = c("king", "king", "ccho"), 
                   stg = c("smolt", "parr", "smolt"),
                   ct =  c(293L, 410L, 210L))

with the following accompanying metadata:

 col_metadata = c(river = "http://dbpedia.org/ontology/River",
                  spp = "http://dbpedia.org/ontology/Species", 
                  stg = "Life history stage",
                  ct = "count")
 unit_metadata = 
  list(river = c(SAC = "The Sacramento River", AM = "The American River"),
       spp = c(king = "King Salmon", ccho = "Coho Salmon"),
       stg = c(parr = "third life stage", smolt = "fourth life stage"),
       ct = "number")

into EML.

[cboettig]

Basic writing of a valid EML object from an R data.frame is now implemented:

Given the data and metadata above, we simply do:

eml$set(givenName = "Carl", surName = "Boettiger", email = "cboettig@ropensci.org")
eml_write(dat, col_metadata, unit_metadata, file="my_eml_data.xml")

• We translate R object types (integer, float, factor, character string, POSIXt time) automatically
• Generates minimal EML (A dataset node with a contact node and dataTable node)

Much to be done in providing additional metadata fields and support for alternative data types, units, and formats. See issues under write eml.