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couch-r.md

Clients

R4CouchDB

https://github.com/wactbprot/R4CouchDB A R convenience layer for CouchDB. R4CouchDB unites http://www.omegahat.org/RCurl and http://www.omegahat.org/RJSONIO and implements a part of the CouchDB API.

sofa

https://github.com/sckott/sofa An easy interface to CouchDB from R. sofa uses https://github.com/hadley/httr and http://plyr.had.co.nz/

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h3. Clients

h5. R4CouchDB

https://github.com/wactbprot/R4CouchDB

h6. Description

A R convenience layer for CouchDB. R4CouchDB unites http://www.omegahat.org/RCurl and http://www.omegahat.org/RJSONIO and implements a part of the CouchDB API. h6. Example

h.6 Installation

R4CouchDB is part of the cran cosmos so one can say

R> install.packages("R4CouchDB")

h.6 Example

The example below presumes a running CouchDB on http://localhost:5984. First load the R4CouchDB as usual

library("R4CouchDB")

then generate the connection or interface list (here stored in the variable cdb) by

R> cdb <- cdbIni()

cdb assumes some defaults such as

R> cdb$serverName [1] "localhost"

and

R> cdb$port [1] "5984"

Now straight forward: we make a database on http://localhost:5984/r-example, load some fancy volcano data, and write the date (plus some demo info) to a new database document:

R> cdb$newDBName <- "r-example" R> cdb <- cdbMakeDB(cdb) R> data(volcano) R> rdoc <- list(date = date(), data = volcano, dim = dim(volcano)) R> cdb$dataList <- rdoc R> res <- cdbAddDoc(cdb)$res R> res $ok [1] TRUE

$id [1] "26659bf9e39fb9ad6278325963643246"

$rev [1] "1-44e4052a2ef00a8574cad2210e1cfc8e"

We now make a plot of the volcano with the data from the database. At first we get back the data:

cdb$id <- res$id cdoc <- cdbGetDoc(cdb)$res

we regenerate the volcano matrix from this (cdoc) list:

mat <- matrix(data = t(unlist( cdoc$data )), nrow = cdoc$dim[[2]],
ncol = cdoc$dim[[1]])

And here we are:

R> png("r-example.png") R> persp(mat, theta = 120, phi = 30, col = "green3", shade = 0.75 ) R> dev.off()

h5. sofa

https://github.com/sckott/sofa

An easy interface to CouchDB from R. sofa uses https://github.com/hadley/httr and http://plyr.had.co.nz/

h6. Installation

sofa can be installed from github using devtools:

R> install.packages("devtools") R> library(devtools) R> install_github("sofa", "sckott")

h6. Example

Load the package

library('sofa')

Ping the CouchDB server

sofa_ping()

$couchdb
[1] "Welcome"

$uuid
[1] "2c10f0c6d9bd17205b692ae93cd4cf1d"

$version
[1] "1.5.0"

$vendor
$vendor$version
[1] "1.5.0-1"

$vendor$name
[1] "Homebrew"

Create a CouchDB

sofa_createdb(dbname='sofadb')

$ok
[1] TRUE

List your couches

sofa_listdbs()

[1] "_replicator" "_users"      "cachecall"   "mran"        "mydb"        "sofadb" 

Write and get documents

doc1 <- '{"name":"my_favorite_beer","beer":"IPA"}'
sofa_writedoc(dbname="sofadb", doc=doc1, docid="beer")

$ok
[1] TRUE

$id
[1] "beer"

$rev
[1] "1-449148505e2ac94f57d0aa2e68a50b0d"

sofa_getdoc(dbname="sofadb", docid="beer")

$`_id`
[1] "beer"

$`_rev`
[1] "1-449148505e2ac94f57d0aa2e68a50b0d"

$name
[1] "my_favorite_beer"

$beer
[1] "IPA"

List changes

sofa_changes(dbname="sofadb")

$results
$results[[1]]
$results[[1]]$seq
[1] 1

$results[[1]]$id
[1] "beer"

$results[[1]]$changes
$results[[1]]$changes[[1]]
$results[[1]]$changes[[1]]$rev
[1] "1-449148505e2ac94f57d0aa2e68a50b0d"





$last_seq
[1] 1