Unified access to your data sources

Provides an S4 infrastructure for unified handling of internal datasets and web based data sources. The package is currently in beta; things may break, change or go away without warning.


datamart Version 0.5.1


  • The Mashup class has been rewritten. The changes are not backward compatible. The new implementation paves the way to a make-like, declarative data build process.

  • The Blogger class has been rewritten in order to use the OAuth2 interface for posting.

  • The InternalData class has been rewritten. The changes are not backward compatible. The resource name(s) for dataset is/are now predefined through the dataset name(s). Hence it is not possible to set the resource name elsewhere. This was necessary as internal datasets may comprise several data entities.

  • The Xsparql2 class with its constructor xsparql2 has been renamed to Xsparql/xsparql. At this experimental stage, the classes and interfaces are still changing, breaking existing code. Hence naming new versions of an idea differently is not necessary in my opinion.

  • The UrlData3 class has been renamed to UrlData.


  • a class CsvData for administrating tabular data: an update mechanism, keeping metadata on the dataset and on dataset columns.


  • New unit sets for area and volume are introduced. Also, the self-tests for the uconv function have been revised.

  • New class GoogleOAuth2 which enables connection with Google services such as Blogger. It manages a file with the access token, so that acquiring an access token through authentication is necessary only once.

  • New XSPARQL examples on power plants: openei() and enipedia()

  • The gapminder() datamart, which was removed for the last few versions, has returned.

  • improved documentation: partly due to new version of roxygen, partly due to usage of href instead of url, added @seealso where appropriate


  • removed the unit set for temperature. Since the unit conversion between degree F and degree C is affine but not homogen, it is not easy to fit it in the existing code. May return in later version, but I need to rethink the concept first.

  • removed siunit and mySPARQL documentation. These are internal functions.

datamart Version 0.4.2


  • The data object returned by sourceforge() now has only one resource "SourceforgeStats" and additional parameters from and to. The sourceforge() function accepts a optional clss parameter.

  • The data object returned by city_coords() now has only one resource "CityCoordinates" and takes additional parameters city and country (optional, default DE).


  • A new generic with the name "put" is introduced.

  • A new generic "meta" for Location classes is introduced and implemented for Blogger and DirectoryLocation.


  • new UrlData3 example netConnectGermany

  • new Mashup / UrlData3 example eurostat_web

  • new UrlData3 example oddsportal

  • Bugfix for uconv, check for valid temperature units added.

  • Bugfix for strsubst, unhelpful error message when one escape sequence is invalid fixed..

  • Fixed test for strsubst. Added minimal first test for uconv.

  • Worked on the documentation, it is still not satisfactory.

  • Moved "Depends" to "Imports", removed dependency on RSQLite package.


  • urldata and urldata2 have been removed. Instead, urldata3 is the way to go. The first official version of the package (1.0) will rename urldata3 to urldata.

  • The naming "build" was not a good idea and has been removed. It is now called "put".

  • The unitsets CrudeOil and GaseousFuels have been removed. They are now part of "Energy". The code for the "uconv" function has been rewritten.

  • The mauna_loa, tour_de_france, gscholar and gapminder dataset have been removed. First need to look into into it. May return in later versions.

  • The DataStore concept has been removed. The "put" generic will replace that.

datamart Version 0.3.2


  • The InternalData function has been rewritten and may behave different to prior versions.


  • A build mechanism with the new generic build is introduced. The build method takes at least a Target object and a Location object. Examples for targets are swvreport and mdreport; examples for locations are DirectoryLocation and Blogger.

  • new function uconv to convert between measurement units.


  • new UrlData example cityCoords

  • simplified constructor for class DataStoreDriver

  • first tests cases added

  • NEWS file added


  • removed function wikisites

datamart Version 0.2.0


  • new fundamental class UrlData, with examples mauna_loa, iwv_online, be_bathing_water_quality, sourceforge, gapminder, tourdefrance

  • new fundamental class Mashup, with experimental example eurostat

  • mechanism for persistence, classes DataStoreDriver and SQLiteDataStore with adapted generics, and new generics scrape and scrapes


  • class GScholar for querying Google scholar (inherited from UrlData), with example statsoft_popularity

  • some string utility functions added, strhead, strtail, strencrypt, strdecrypt, strsubst, strparse, strrecode, strcap

  • mem.info introspection function

datamart Version 0.1.0


  • base class Xdata, with query and queries generics

  • InternalData as one workhorse, Evs as example

  • Xsparql as second workhorse, Dbpedia as example

  • Twttr example

Reference manual

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0.5.2 by Karsten Weinert, 6 years ago

Browse source code at https://github.com/cran/datamart

Authors: Karsten Weinert

Documentation:   PDF Manual  

Task views: Web Technologies and Services

GPL (>= 3) license

Imports RJSONIO, XML, RCurl, base64, gsubfn, methods, markdown

See at CRAN