R
Notes
Guides:
source('somefile.R') sink('somrfile.txt', append=TRUE); # Write (append) to file sink() # Return to terminal png('somefile.png') # Redirect to image plot(x) dev.off() # Stop writing to image q() # Quit
Running R from an external script
- -f something.R
RPostgreSQL
Include lib:
library(RPostgreSQL)
Example of connecting to postgres:
drv <- dbDriver('PostgreSQL') con <- dbConnect(drv, dbname='somedatabase', user='someuser', pass='somepass') data <- dbReadTable(con, 'sometable') head(data, 100) dbDisconnect(con) dbUnloadDriver(drv)
Or like this with SQL/fetch (large tables can be streamed):
drv <- dbDriver('PostgreSQL') con <- dbConnect(drv) res <- dbSendQuery(con, 'SELECT * from sometable') data <- fetch(res, n = -1)
See also here