search for: ffmode

...mands. library(ff) x<-ff(1:5,length=5,update=TRUE,vmode="double",filename="header.ff",overwrite=TRUE) Afterwards, I got the following error message. *** caught segfault *** address 0xffffffff, cause 'memory not mapped' Traceback: 1: .Call("get_vector", .ffmode[vmode], attr(x, "physical"), index, nreturn, PACKAGE = "ff") 2: `[.ff`(ret, 1) 3: ret[1] 4: as.vector(ret[1]) 5: identical(as.vector(initdata[1]), as.vector(ret[1])) 6: ff(1:5, length = 5, update = TRUE, vmode = "double", filename = "header.ff",...

Hi Does anybody know how to create ff objects with data reading from stream objects, such as data reading from PostgreSQL database through RPostgreSQL. For this purpose although we can save the data to a csv file through external tools and then read it through csv readers, but it requires one more data read and write operation, which is of high I/O cost for large datasets. Xiaobo.Gu