Alistair Miles
Thu, 12 Feb 2009 02:31:49 -0800
Hi all, This is just an update to say that I've converted the LOC/scriblio data to marc xml and from there to mods xml. My next step is to do some analysis of the loc data in mods xml to get an overview of the elements used, then to try to design at least a partial mapping from mods xml to RDF using the RDA and FRBR schemas. FYI the marc xml and mods xml versions of the LOC/scriblio data can be downloaded from the links below... http://dcmi-rda.s3.amazonaws.com/locdata/part01-marcxml.tar.gz http://dcmi-rda.s3.amazonaws.com/locdata/part01-modsxml.tar.gz http://dcmi-rda.s3.amazonaws.com/locdata/part02-marcxml.tar.gz http://dcmi-rda.s3.amazonaws.com/locdata/part02-modsxml.tar.gz [...] http://dcmi-rda.s3.amazonaws.com/locdata/part29-marcxml.tar.gz http://dcmi-rda.s3.amazonaws.com/locdata/part29-modsxml.tar.gz Each download is a gzipped tar containing a *set* of up to 25 xml files. Each of these files is a 10,000 record split of the data in the corresponding part. I broke each part into 10,000 record splits so I could process the transformations more easily. N.B. there is a bug in part 13 split 25, for some reason the marc xml output was incomplete so up to 10,000 records could be missing. FWIW I initially tried the conversions without splitting each part. I.e. I converted each original marc file into a single marc xml file, then tried to transform that to a mods xml file via xsltproc. However I found you need more than 7GB ram to do the marcxml to modsxml transform on a whole part (I tried it on a large ec2 instance), so that's when I decided to split each part into smaller chunks, which I figured would be faster to process and more amenable to parallel processing (transforming all the splits from marcxml to modsxml took a couple of hours on a c1.xlarge ec2 instance, running up to 10 transformations in parallel; it can also be done on a laptop, but takes ~10 times longer). Btw if anyone else has experience of the marcxml->modsxml transform on a file of similar size do let me know, I don't do a lot of xslt-ing so may be missing some tricks for making it work on smaller computers. Cheers, Alistair On Mon, Dec 22, 2008 at 03:31:50PM -0500, Ed Summers wrote: > Hey Alistair: > > On Mon, Dec 22, 2008 at 1:16 PM, Alistair Miles > <alistair.mi...@zoo.ox.ac.uk> wrote: > > Any tips for how I could turn these data into RDF? > > If you want to work specifically with that dataset you could download > the different parts Karen pointed you to, and convert to MARCXML using > an efficient tool like yaz-marcdump [2]. yaz-marcdump is nice it will > convert from MARC-8 to UTF-8. > > Once you've got it in MARCXML you could then use a stylesheet like > LC's [2] to convert to DublinCore flavored RDF. This might be kinda > lossy for your RDA work though, so you might want MARCXML->MODS [3], > and then use the MODS->RDF conversion that the Simile folks created > (which Karen also pointed you to) [4]. > > In fact Simile used that stylesheet on their own MIT Library Catalog > MARC data (Barton) and still seem to have the result online [5]. So > perhaps just using the Barton data is the quickest way to begin > playing with what once was MARC data as RDF? To my knowledge Stefano > Mazzocchi simply created an RDF vocabulary that mirrors the MODS XML > Schema, but I haven't looked at it in a while. > > Another thing worth checking out might be Rob Styles work [6] with > other people at Talis at converting MARC with full fidelity to RDF. > Perhaps he has some tools (or data) at his disposal? Rob you are on > here right? > > I'd be willing to lend a hand with some of this if necessary, so just > let me know if you think I can help. > > //Ed > > [1] http://www.indexdata.com/yaz/doc/yaz-marcdump.tkl > [2] http://www.loc.gov/standards/marcxml/xslt/MARC21slim2RDFDC.xsl > [3] http://www.loc.gov/standards/mods/v3/MARC21slim2MODS3.xsl > [4] http://simile.mit.edu/wiki/MARC/MODS_RDFizer > [5] http://simile.mit.edu/wiki/Dataset:_Barton > [6] > http://events.linkeddata.org/ldow2008/papers/02-styles-ayers-semantic-marc.pdf -- Alistair Miles Senior Computing Officer Image Bioinformatics Research Group Department of Zoology The Tinbergen Building University of Oxford South Parks Road Oxford OX1 3PS United Kingdom Web: http://purl.org/net/aliman Email: alistair.mi...@zoo.ox.ac.uk Tel: +44 (0)1865 281993