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JGCRI / gcam-core

GCAM -- The Global Change Analysis Model
http://jgcri.github.io/gcam-doc/
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XML Queries Documentation #111

Open thompsoa opened 4 years ago

thompsoa commented 4 years ago

Is there any documentation available about how the XML queries of the database should be written?

I'm trying to access the data from some GCAM runs via rgcam and would like to optimise the query file that I'm using to extract the variables I need but I'm not sure how to set that up.

I'm starting from the sample-queries.xml file that came with rgcam.

For example, it would be useful to be able to see a full list of outputs which can be extracted from a run, and how to aggregate data - e.g. to get the global total sequestration, not split by region.

VincenzoFrasca commented 3 years ago

I'm facing the same need as @thompsoa, are there any updates on this issue?

kvcalvin commented 3 years ago

There is some information available. We have added information on outputs and their queries to the documentation (see http://jgcri.github.io/gcam-doc/outputs_quantity.html as an example and http://jgcri.github.io/gcam-doc/index.html for other outputs_ pages).

pralitp commented 3 years ago

I would also suggest checking the Main_queries.xml which is more complete than the examples in rgcam and kept up to date. It is the place we draw the queries from in our documentation.

The queries are built upon the standard XPath (and in a few cases XQuery) syntax. You can find many resources online about the syntax, available functions, and general tips. Which you could then take advantage of to customize the examples found in Main_queries.xml for your needs.