Data sources

Data servers:
  * oai-pmh
  * opendap (open ndap)
    * pyndap

Display and manipulation
  * automatic combination
  * visualization


Tasks:

1. Getting data and distributing data

2. Identifying data

3. Combining data

4. Visualizing data

Econonomics tool:

  * Data repository (many)
  * Visualization separate
    * should be v. simple
    * multiple plots
    * select which columns
  * conversion to right form for visualization should be M+N
    * have M input formats and N visualization formats
    * plugins ...
  * indexer separate from the repository (so that we can pick data to look at)
  * repository are independent

## A Summary of OPeNDAP (open network data access protocol)

An abstract of:
  * [1] <http://www.opendap.org/user/quick-html/quick_1.html>

Originally developed by oceaneographic institute as DODS (Distributed Oceanographic Data System) as a protocol for accessing and serving data in a manner that is transparent for remote users.

Main aspects are:

  1. Metadata
    1. Dataset Descriptor Structure  (DDS) -- Structure of the data. "This provides a description of the "shape" of the data, using a vaguely C-like syntax. You get a dataset's DDS by appending .dds to the URL."
    2. Data Attribute Structure (DAS) -- "contains information about the data, such as units and the name of the variable"
      * "NOTE: The DAS is populated at the data provider's discretion. Because of this, the quality of the data in it (the metadata) varies widely. The data in the Reynolds dataset used in this example are COARDS compliant. Other metadata standards you may encounter with DODS data are HDF-EOS, EPIC, FGDC, or no metadata at all."

Web api

base uri:

<http://www.cdc.noaa.gov/cgi-bin/nph-nc/Datasets/reynolds_sst/sst.mnmean.nc>

dds: append .dds to the url

das: append .das to the url

info service: append .info to the url to get back DDS and DAS

html query: Append .html to the URL, and you get a form that directs you to add information to sample the data at a URL

query string:
  * {url}?{array-name}[{restriction ...}]
    * e.g. ...sst/mnmean.nc.asc?time[0:6]

