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## ----include=FALSE------------------------------------------------------------
options(rdf_print_format = "nquads")
## ----message = FALSE, warning=FALSE-------------------------------------------
library(rdflib)
library(dplyr)
library(tidyr)
library(tibble)
library(jsonld)
## -----------------------------------------------------------------------------
car_triples <-
mtcars %>%
rownames_to_column("Model") %>%
gather(attribute,measurement, -Model)
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(car_triples)
## -----------------------------------------------------------------------------
car_triples <-
mtcars %>%
rownames_to_column("Model") %>%
rowid_to_column("subject") %>%
gather(predicate, object, -subject)
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(car_triples)
## -----------------------------------------------------------------------------
iris_triples <- iris %>%
rowid_to_column("subject") %>%
gather(key = predicate, value = object, -subject)
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(iris_triples)
## -----------------------------------------------------------------------------
iris_triples <- iris %>%
rowid_to_column("subject") %>%
mutate(subject = paste0("http://example.com/iris#", subject)) %>%
gather(key = predicate, value = object, -subject)
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(iris_triples)
## ----mesage = FALSE-----------------------------------------------------------
iris_triples <- iris %>%
rowid_to_column("subject") %>%
mutate(subject = paste0("http://example.com/iris#", subject)) %>%
gather(key = predicate, value = object, -subject) %>%
mutate(predicate = paste0("http://example.com/iris#", predicate))
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(iris_triples)
## -----------------------------------------------------------------------------
rdf <- rdf()
## -----------------------------------------------------------------------------
base <- "http://example.com/iris#"
rdf %>%
rdf_add(subject = paste0(base, "obs1"),
predicate = paste0(base, "Sepal.Length"),
object = 5.1)
rdf
## -----------------------------------------------------------------------------
rdf <- rdf()
rdf %>% rdf_add("",
"iris:Sepal.Length",
object = 5.1)
rdf
## -----------------------------------------------------------------------------
rdf_serialize(rdf, "rdf.nq", format = "nquads")
## -----------------------------------------------------------------------------
doc <- system.file("extdata/example.rdf", package="redland")
rdf <- rdf_parse(doc, format = "rdfxml")
rdf
## -----------------------------------------------------------------------------
options(rdf_print_format = "rdfxml")
rdf
## -----------------------------------------------------------------------------
options(rdf_print_format = "turtle")
rdf
## -----------------------------------------------------------------------------
options(rdf_print_format = "jsonld")
rdf
## -----------------------------------------------------------------------------
rdf_serialize(rdf, "example.json", "jsonld") %>%
jsonld_compact(context = '{"@vocab": "http://purl.org/dc/elements/1.1/"}')
## -----------------------------------------------------------------------------
ex <- system.file("extdata/person.json", package="rdflib")
cat(readLines(ex), sep = "\n")
#jsonld_compact(ex, "{}")
## -----------------------------------------------------------------------------
options(rdf_print_format = "nquads")
rdf <- rdf_parse(ex, "jsonld")
rdf
## -----------------------------------------------------------------------------
jsonld_flatten(ex, context = "http://schema.org")
## -----------------------------------------------------------------------------
jsonld_flatten(ex) %>%
jsonld_frame('{"@type": "http://schema.org/Person"}') %>%
jsonld_compact(context = "http://schema.org")
## -----------------------------------------------------------------------------
as_rdf.list <- function(x, context = "http://schema.org"){
if(length(x) == 1) x <- x[[1]]
x[["@context"]] <- context
json <- jsonlite::toJSON(x, pretty = TRUE, auto_unbox = TRUE, force = TRUE)
rdflib::rdf_parse(json, "jsonld")
}
## -----------------------------------------------------------------------------
context <- list("http://schema.org",
list(schema = "http://schema.org/",
given = "givenName",
family = "familyName",
title = "name",
year = "datePublished",
note = "softwareVersion",
comment = "identifier",
role = "http://www.loc.gov/marc/relators/relaterm.html"))
## -----------------------------------------------------------------------------
options(rdf_print_format = "nquads") # go back to the default
R <- citation("rdflib")
rdf <- as_rdf.list(R, context)
rdf
## -----------------------------------------------------------------------------
#source(system.file("examples/as_rdf.R", package="rdflib"))
source(system.file("examples/tidy_schema.R", package="rdflib"))
## Testing: Digest some data.frames into RDF and extract back
cars <- mtcars %>% rownames_to_column("Model")
x1 <- as_rdf(iris, NULL, "iris:")
x2 <- as_rdf(cars, NULL, "mtcars:")
rdf <- c(x1,x2)
## -----------------------------------------------------------------------------
sparql <-
'SELECT ?Species ?Sepal_Length ?Sepal_Width ?Petal_Length ?Petal_Width
WHERE {
?s <iris:Species> ?Species .
?s <iris:Sepal.Width> ?Sepal_Width .
?s <iris:Sepal.Length> ?Sepal_Length .
?s <iris:Petal.Length> ?Petal_Length .
?s <iris:Petal.Width> ?Petal_Width
}'
iris2 <- rdf_query(rdf, sparql)
## ----echo=FALSE---------------------------------------------------------------
DT::datatable(iris2)
## -----------------------------------------------------------------------------
sparql <- tidy_schema("Species", "Sepal.Length", "Sepal.Width", prefix = "iris")
rdf_query(rdf, sparql)
|
