similar to: Reading in csv data with ff package

Displaying 20 results from an estimated 5000 matches similar to: "Reading in csv data with ff package"

2010 Dec 24
1
How to specify ff object filepaths when reading a CSV file into a ff data frame.
Hi, The read.csv.ffdf function in package ff will create the ff object physical file in the default directories, I am trying to let the files created in the paths users specify, I think the point is to make use of the asffdf_args parameter, I have a test CSV file named D:\rtemp\fftest.csv, the content of the file is as following: col1,col2,col3 1,"amber",2.4 2,"linda",4.5
2012 Jul 25
3
ff package: reading selected columns from csv
*Dear R users, Ive just started using the ff package. There is a csv file (~4Gb) with 7 columns and 6e+7 rows. I want to read only column from the file, skipping the first 100 rows. Below Ive provided different outcomes, which will clarify my problem * > sessionInfo() R version 2.14.2 (2012-02-29) Platform: x86_64-pc-mingw32/x64 (64-bit) locale: ... attached base packages: [1] tools
2012 Mar 30
3
ff usage for glm
Greetings useRs, Can anyone provide an example how to use ff to feed a very large data frame to glm? The data.frame cannot be loaded in R using conventional read.csv as it is too big. glm(...,data=ff.file) ?? Thank you Stephen B
2012 Sep 14
1
Any way to get read.table.ffdf() (in the ff package) to pass colClasses or comment.char parameters through to read.fwf() ?
Hi everyone, my apologies if I'm overlooking something obvious in the documentation. I'm relatively inexperienced with the (awesome) ff package. My goal is to use the read.table.ffdf() function to call the read.fwf() function and pass through the colClasses and comment.char arguments. The code below shows exactly what doesn't work for me. If the colClasses and comment.char
2011 May 04
1
Problems saving ff objects
Dear list, I am trying to understand and use the ff package. As I had some problems saving some ff objects, and as I did not fully manage to understand the whole concept of *.ff, *.ffData and *.RData with the help of the documentation, I tried to reproduce the examples from the help of ffsave. When I ran, however : (copied from the help) message("let's create some ff objects")
2013 Sep 30
4
read.table() with quoted integers
Hi! It seems that read.table() in R 3.0.1 (Linux 64-bit) does not consider quoted integers as an acceptable value for columns for which colClasses="integer". But when colClasses is omitted, these columns are read as integer anyway. For example, let's consider a file named file.dat, containing: "1" "2" > read.table("file.dat",
2011 Feb 02
1
Error of 'memory not mapped' in ff Package with VirtualBox
Dear R Helpers, I would like to report on an error in the ff package here. The ff package is an R package which enables us to store large data on disk systematically and have fast access to the database. I used the package in Linux as a guest OS of VirtualBox, and executed the following commands. library(ff)
2010 Jan 07
1
A question about the ff package
Hi, I am using version 2.1-1 of the ff package. I have a data set with 80 million rows and I need to create a new ffdf object, subseting by values in one of the original ffdf's columns. Here is my code: bigData <- read.table.ffdf(file="/data/demodata/data/smallData.txt", next.rows=1e5, head=TRUE, sep="|") dim(bigData) N <- nrow(bigData);N select <- ff(
2012 Oct 31
1
ffdfindexget from package ff
I'm having trouble getting ffdfindexget to work right in Windows. Even the most trivial of examples gives me problems. > myVec = ff(1:5) > another = ff(10:14) > littleFrame = ffdf(myVec, another) > posVec = ff(c(2, 4), vmode = 'integer') > ffdfindexget(littleFrame, posVec) Error in if (any(B < 1)) stop("B too small") : missing value where TRUE/FALSE
2011 Jan 18
2
help with read.table.ffdf parameters
Hello fellow R users, I am trying to read a 6.9 million row text file with 26 columns separated by spaces into R using ff. When I specify a small number for first.rows, next.rows and nrows it is read with no issue. However, when I try to specify larger next.rows values and no nrows parameter to read the entire file, I keep getting errors. Please see code below. I am trying to this on a m1.large
2010 Nov 10
1
ff objects saving problem
Hi, I am running the examples in page 70 of the ff package document, but it failed with the following error > cat("let's create some ff objects\n") let's create some ff objects > n <- 8e3 > a <- ff(sample(n, n, TRUE), vmode="integer", length=n, filename="d:/tmp/a.ff") > b <- ff(sample(255, n, TRUE), vmode="ubyte", length=n,
2013 Feb 27
0
How to specify ff object filepaths when reading a CSV file into a ff data frame.
Really old subject?, so, all my apologizes for digging up but, since I also ran into this? maybe this hack can be useful to someone I propose monkey patching here: library(ff) my.as.ffdf.data.frame <- function (x, vmode = NULL, col_args = list(), ...) { rnam <- attr(x, "row.names") if (is.integer(rnam)) { if (all(rnam == seq_along(rnam))) rnam <- NULL else
2012 Oct 02
1
ffsave problems
Dear R friends. After having some troubles learning how to create a ffdf object, now I find myself having problems saving it. this is the data i´d like to save: str(DATA) List of 3 $ virtual: 'data.frame': 6 obs. of 7 variables: .. $ VirtualVmode : chr "double" "short" "integer" "integer" ... .. $ AsIs : logi FALSE FALSE FALSE
2010 Apr 13
2
how to work with big matrices and the ff-package?
Hello everyone, I need to create and work with some big matrices that actually have somewhat over 2 million columns and 117 rows. To do some calculations on such big matrices R just needs too much memory for my PC (4GB installed). So I need a solution to work with large datasets. I'm trying to use the ff-package but I don't think I really understand the whole functionality of the
2010 Oct 01
0
ff version 2.2.0
Dear R community, The next release of package ff is available on CRAN. With kind help of Brian Ripley it now supports the Win64 and Sun versions of R. It has three major functional enhancements: a) new fast in-memory sorting and ordering functions (single-threaded) b) ff now supports on-disk sorting and ordering of ff vectors and ffdf dataframes c) ff integer vectors now can be used as
2010 Oct 01
0
ff version 2.2.0
Dear R community, The next release of package ff is available on CRAN. With kind help of Brian Ripley it now supports the Win64 and Sun versions of R. It has three major functional enhancements: a) new fast in-memory sorting and ordering functions (single-threaded) b) ff now supports on-disk sorting and ordering of ff vectors and ffdf dataframes c) ff integer vectors now can be used as
2009 Nov 25
3
questions on the ff package
Hi, I have two questions on using the ff package and wonder if anyone who used ff can share some thoughts. I need to save a matrix as a memory-mapped file and load it back later. To save the matrix, I use mat = matrix(1:20, 4, 5) matFF = ff(mat, dim=dim(mat), filename="~/a.mat", overwrite=TRUE, dimnames = dimnames(mat)) To load it back, I use matFF2 = ff(vmode = "double",
2009 Nov 09
3
Hand-crafting an .RData file
Hello, I frequently have to export a large quantity of data from some source (for example, a database, or a hand-written perl script) and then read it into R. This occasionally takes a lot of time; I'm usually using read.table("filename",comment.char="",quote="") to read the data once it is written to disk. However, I *know* that the program that generates
2010 Jun 11
1
ff package when reading .csv files
Hi My aim is to read a large .csv file into R. I ran the following code and am using R version 10.1 on Windows. >library(ff) > read.csv.ffdf(x=NULL,"file.csv",fileEncoding="",nrows=-1,first.rows=NULL,next.rows=NULL,levels=NULL,appendLevels=TRUE,FUN="read.table",transFUN=NULL,asffdf_args=list(),BATCHBYTES=getOption("ffbatchbytes"),VERBOSE=FALSE)
2010 Aug 01
1
How to create ff objects from database connection
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