rsdmx: Tools for reading SDMX data and metadata
documents in R
rsdmx is a package to parse/read SDMX data and metadata
in R. It provides: * a set of classes and methods to read data and
metadata documents exchanged through the Statistical Data and Metadata
Exchange (SDMX) framework. The package currently focuses on the SDMX XML
standard format (SDMX-ML). * an interface to SDMX web-services for a
list of well-known data providers, such as EUROSTAT, OECD, and others Learn
more.
We thank in advance people that use rsdmx for citing it
in their work / publication(s). For this, please use the citation
provided at this link
In spite they are some R package initiatives relying on
rsdmx that aim to provide a wrapper for a single data
source (e.g. OECD, EUROSTAT), it is strongly recommended to rely
directly on rsdmx. Indeed, one main objective of
rsdmx is to promote and facilitate collating
scattered data from a growing number of SDMX data providers,
whatever the organization.
It is already possible to query well-known datasources, using the
embedded helpers.
Pull requests are welcome to support additional data providers by
default in rsdmx.
At now, the package allows to read: * Datasets
(GenericData, CompactData,
StructureSpecificData,
StructureSpecificTimeSeriesData,
CrossSectionalData, UtilityData and
MessageGroup SDMX-ML types) * Concepts
(Concept, ConceptScheme and
Concepts SDMX-ML types) * Codelists (Code,
Codelist and Codelists SDMX-ML types) *
DataStructures / KeyFamilies - with all subtypes * Data Structure
Definitions (DSDs) - with all subtypes
rsdmx is looking for sponsors.
You have been using rsdmx and you wish to support its
development? Please help us to make the package growing!
Copyright (C) 2014 Emmanuel Blondel
rsdmx is available on the Comprehensive R Archive
Network (CRAN). See the R CRAN check results at: https://cran.r-project.org/web/checks/check_results_rsdmx.html
Please note that following a new submission to CRAN, or eventually a modification of CRAN policies, the package might be temporarily archived, and removed from CRAN. In case you notice that the package is not back in few time, please contact me.
rsdmx is available on the R-Universe public cloud
server. The package version corresponds to the ongoing revision (master
branch in Github). See https://opensdmx.r-universe.dev/#package:rsdmx
rsdmx offers a
low-level set of tools to read data and
metadata in SDMX format. Its strategy is to make it
very easy for the user. For this, a unique function named
readSDMX has to be used, whatever it is a data
or metadata document, or if it is local or
remote datasource.
It is important to highlight that one of the major benefits of
rsdmx is to focus first on the SDMX format
specifications (acting as format abstraction library). This allows
rsdmx reading SDMX data from remote datasources,
or from local SDMX files. For accessing remote
datasources, it also means that rsdmx does not bound to
SDMX service specifications, and can read a wider
ranger of datasources.
rsdmx can be installed from CRAN
{r, echo = FALSE} install.packages("rsdmx")
or from its development repository hosted in Github (using the
devtools package):
{r, echo = FALSE} devtools::install_github("opensdmx/rsdmx")
To load rsdmx in R, do the following:
{r, echo = FALSE} library(rsdmx)
The readSDMX function is then first designed at
low-level so it can take as parameters a url
(isURL=TRUE by default) or a file. So wherever is
located the SDMX document, readSDMX will allow you to read
it, as follows:
```{r, echo = FALSE}
#read a remote file sdmx <- readSDMX(file = “someUrl”)
#read a local file sdmx <- readSDMX(file = “somelocalfile”, isURL = FALSE)
In addition, in order to facilitate querying datasources, ``readSDMX`` also providers helpers to query well-known remote datasources. This allows not to specify the entire URL, but rather specify a simple provider ID, and the different parameters to build a SDMX query (e.g. for a dataset query: operation, key, filter, startPeriod and endPeriod).
This is made possible as a list of SDMX service providers is embedded within ``rsdmx``, and such list provides all the information required for ``readSDMX`` to build the SDMX request (url) before accessing the datasource.
#### get list of SDMX service providers
The list of known SDMX service providers can be queried as follows:
```{r, echo = FALSE}
providers <- getSDMXServiceProviders()
as.data.frame(providers)
It also also possible to create and add a new SDMX service providers
in this list (so readSDMX can be aware of it). A provider
can be created with the SDMXServiceProvider, and is made of
various parameters: * agencyId (provider identifier) *
name * scale (international or national) *
country ISO 3-alpha code (if national) *
builder
The request builder can be created with
SDMXRequestBuilder which takes various arguments: *
regUrl: URL of the service registry endpoint *
repoUrl: URL of the service repository endpoint (Note that
we use 2 different arguments for registry and repository endpoints,
since some providers use different URLs, but in most cases those are
identical) * formatter list of functions to format the
request params (one function per type of resource, e.g. “dataflow”,
“datastructure”, “data”) * handler list of functions which
will allow to build the web request *compliant logical
parameter (either the request builder is compliant with some web-service
specifications)
rsdmx yet provides common builders, that can be
customized if needed, by overriding either the formatter or
the handler functions: *
SDMXREST20RequestBuilder: connector for SDMX REST 2.0
web-services * SDMXREST21RequestBuilder: connector for SDMX
REST 2.1 web-services * SDMXDotStatRequestBuilder:
connector for SDMX .Stat (“DotStat”) web-services implementations
Let’s see it with an example:
First create a request builder for our provider:
```{r, echo = FALSE}
myBuilder <- SDMXRequestBuilder( regUrl = “http://www.myorg.org/sdmx/registry”, repoUrl = “http://www.myorg.org/sdmx/repository”, formatter = list( dataflow = function(obj){ #format each dataflow id with some prefix obj@resourceId <- paste0(“df_”,obj@resourceId) return(obj) }, datastructure = function(obj){ #do nothing return(obj) }, data = function(obj){ #format each dataset id with some prefix obj@flowRef <- paste0(“data_”,obj@flowRef) return(obj) } ), handler = list( dataflow = function(obj){ req <- sprintf(“%s/dataflow”,obj@regUrl) return(req) }, datastructure = function(obj){ req <- sprintf(“%s/datastructure”,obj@regUrl) return(req) }, data = function(obj){ req <- sprintf(“%s/data”,obj@regUrl) return(req) } ), compliant = FALSE )
As you can see, we built a custom ``SDMXRequestBuilder`` that will be able to
create SDMX web-requests for the different resources of a SDMX web-service.
We can create a provider with the above request builder, and add it to the list
of known SDMX service providers:
```{r, echo = FALSE}
#create the provider
provider <- SDMXServiceProvider(
agencyId = "MYORG",
name = "My Organization",
builder = myBuilder
)
#add it to the list
addSDMXServiceProvider(provider)
#check provider has been added
as.data.frame(getSDMXServiceProviders())
A another helper allows you to interrogate rsdmx if a
specific provider is known, given an id:
{r, echo = FALSE} oecd <- findSDMXServiceProvider("OECD")
Now you know how to add a SDMX provider, you can consider using
readSDMX without having to specifying a entire URL, but
just by specifying the agencyId of the provider, and the
different query parameters to reach your SDMX document:
{r, echo = FALSE} sdmx <- readSDMX(providerId = "MYORG", providerKey = NULL resource = "data", flowRef="MYSERIE", key = "all", key.mode = "SDMX", start = 2000, end = 2015)
For embedded service providers that require a user
authentication/subscription key or token, it is possible to specify it
in readSDMX with the providerKey argument. If
provided, and that the embedded provider requires a specific key
parameter, the latter will be appended to the SDMX web-request.
The following sections will show you how to query SDMX documents, by
using readSDMX in different ways: either for local
or remote files, using readSDMX as low-level or
with the helpers (embedded service providers).
This section will introduce you on how to read SDMX dataset documents.
The following code snipet shows you how to read a dataset from a remote data source, taking as example the OECD StatExtracts portal: https://sdmx.oecd.org/public/rest/data/DSD_PRICES@DF_PRICES_N_CP01/GRC……./all/?startPeriod=2020&endPeriod=2020
{r, echo = FALSE} myUrl <- "https://sdmx.oecd.org/public/rest/data/DSD_PRICES@DF_PRICES_N_CP01/GRC......./all/?startPeriod=2020&endPeriod=2020" dataset <- readSDMX(myUrl) stats <- as.data.frame(dataset)
You can try it out with other datasources, such as: * EUROSTAT portal: [https://ec.europa.eu/eurostat/SDMX/diss-web/rest/data/nama_10_gdp/.CLV10_MEUR.B1GQ.BE/?startperiod=2005&endPeriod=2011) * European Central Bank (ECB): https://sdw-wsrest.ecb.europa.eu/service/data/DD/M.SE.BSI_STF.RO.4F_N
The online rsdmx documentation also provides a list of data providers, either from international or national institutions.
Now, the service providers above mentioned are known by
rsdmx which let users using readSDMX with the
helper parameters. It may also be the case for a provider that you
register in rsdmx.
Let’s see how it would look like for querying an OECD
datasource:
{r, message = FALSE} sdmx <- readSDMX(providerId = "OECD", resource = "data", flowRef = "DSD_PRICES@DF_PRICES_N_CP01", key = list("GRC", NULL, NULL, NULL, NULL, NULL, NULL, NULL), start = 2020, end = 2020) df <- as.data.frame(sdmx) head(df)
It is also possible to query a dataset together with its
“definition”, handled in a separate SDMX-ML document named
DataStructureDefinition (DSD). It is particularly useful
when you want to enrich your dataset with all labels. For this, you need
the DSD which contains all reference data.
To do so, you only need to append dsd = TRUE (default
value is FALSE), to the previous request, and specify
labels = TRUE when calling as.data.frame, as
follows:
{r, message = FALSE} sdmx <- readSDMX(providerId = "OECD", resource = "data", flowRef = "DSD_PRICES@DF_PRICES_N_CP01", key = list("GRC", NULL, NULL, NULL, NULL, NULL, NULL, NULL), start = 2020, end = 2020, dsd = TRUE) df <- as.data.frame(sdmx, labels = TRUE) head(df)
Note that in case you are reading SDMX-ML documents with the native
approach (with URLs), instead of the embedded providers, it is also
possible to associate a DSD to a dataset by using the function
setDSD. Let’s try how it works:
```{r, message = FALSE} #data without DSD sdmx.data <- readSDMX(providerId = “OECD”, resource = “data”, flowRef = “DSD_PRICES@DF_PRICES_N_CP01”, key = list(“GRC”, NULL, NULL, NULL, NULL, NULL, NULL, NULL), start = 2020, end = 2020)
#DSD sdmx.dsd <- readSDMX(providerId = “OECD”, resource = “datastructure”, resourceId = “DSD_PRICES”)
#associate data and dsd sdmx.data <- setDSD(sdmx.data, sdmx.dsd)
#### Read _local_ datasets
This example shows you how to use ``rsdmx`` with _local_ SDMX files, previously downloaded from [EUROSTAT](https://ec.europa.eu/eurostat).
```{r, echo = FALSE}
#bulk download from Eurostat
tf <- tempfile(tmpdir = tdir <- tempdir()) #temp file and folder
download.file("https://ec.europa.eu/eurostat/estat-navtree-portlet-prod/BulkDownloadListing?sort=1&file=data%2Frd_e_gerdsc.sdmx.zip", tf)
sdmx_files <- unzip(tf, exdir = tdir)
sdmx <- readSDMX(sdmx_files[2], isURL = FALSE)
stats <- as.data.frame(sdmx)
head(stats)
By default, readSDMX considers the data source is
remote. To read a local file, add isURL = FALSE.
This section will introduce you on how to read SDMX
metadata complete
data structure definitions (DSD)
#### Data Structure Definition (DSD)
This example illustrates how to read a complete DSD using a [OECD StatExtracts portal](https://data-explorer.oecd.org/) data source.
```{r, echo = FALSE}
dsdUrl <- "https://sdmx.oecd.org/public/rest/datastructure/all/DSD_PRICES/latest/?references=children"
dsd <- readSDMX(dsdUrl)rsdmx is implemented in object-oriented way with
S4 classes and methods. The properties of S4
objects are named slots and can be accessed with the
slot method. The following code snippet allows to extract
the list of codelists contained in the DSD document, and
read one codelist as data.frame.
{r, echo = FALSE} #get codelists from DSD cls <- slot(dsd, "codelists") codelists <- sapply(slot(cls, "codelists"), function(x) slot(x, "id")) #get list of codelists codelist <- as.data.frame(slot(dsd, "codelists"), codelistId = "CL_TRANSFORMATION") #get a codelist
In a similar way, the concepts of the dataset can be
extracted from the DSD and read as data.frame.
{r, echo = FALSE} #get concepts from DSD concepts <- as.data.frame(slot(dsd, "concepts"))
It is possible to save SDMX R objects as RData file (.RData, .rda, .rds), to then be able to reload them into the R session. It could be of added value for users that want to keep their SDMX objects in R data files, but also for fast loading of large SDMX objects (e.g. DSD objects) for use in statistical analyses and R-based web-applications.
To save a SDMX R object to RData file:
{r, echo = FALSE} saveSDMX(sdmx, "tmp.RData")
To reload a SDMX R object from RData file:
{r, echo = FALSE} sdmx <- readSDMX("tmp.RData", isRData = TRUE)