Displaying 20 results from an estimated 42 matches for "vmode".
Did you mean:
mode
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 rnam <- as.character(rnam)
}
x <- as.list(x)
vmodes <- vector("list", length(x))
if (!is.null(vmode)) {...
2011 May 04
1
Problems saving ff objects
...erstand 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")
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, filename="d:/tmp/b.ff")
x <- ff(sample(255, n, TRUE), vmode="ubyte", length=n, filename="d:/tmp/x.ff")
y <- ff(sample(255, n...
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 FALSE FALSE FALSE
.. $ VirtualIsMatrix : logi FALSE FALSE FALSE FALSE FALSE FALSE
.. $ PhysicalIsMatrix : logi FALSE FALSE FALSE FALSE FALSE FALSE
.. $...
2011 Feb 02
1
Error of 'memory not mapped' in ff Package with VirtualBox
...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)
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,
nr...
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, filename="d:/tmp/b.ff")
> x <- ff(sample(255, n, TRUE), vmode="ubyte", length=n, filename="d:/tmp/x.ff")
> y <- ff(samp...
2009 Nov 25
3
questions on the ff package
...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", dim= ???, filename="~/a.mat", overwrite=F)
However, I don't always know the dimension when loading the matrix back.
If I miss the dim attributes, ff will return it as vector. Is there a way
to load the matrix without specifying the dimension?
The second questio...
2013 Nov 18
1
Reading in csv data with ff package
...ot;'> data =
read.csv.ffdf(x=NULL,file="data.csv",nrows=1001,first.rows = 500,
next.rows = 1005,sep=",",colClasses =
c("integer","character","logical"))Error in ff(initdata = initdata,
length = length, levels = levels, ordered = ordered, :
vmode 'character' not implemented> data =
read.csv.ffdf(x=NULL,file="data.csv",nrows=1001,first.rows = 500,
next.rows = 1005,sep=",",colClasses = rep("character",3))Error in
ff(initdata = initdata, length = length, levels = levels, ordered =
ordered, :
vmode ...
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
2012 Oct 01
3
ffbase, help with %in%
...87 1966 Mensajes de aviso perdidosIn if (useNA == "no") c(NA, NaN) :
la condición tiene longitud > 1 y sólo el primer elemento será usado
in a regular data.frame I use data[a,] to extract the rows that a ==
TRUE, but when i do this in a ffdf i get this error:
> data[a,]Error: vmode(index) == "integer" is not TRUE
I'm just learning how to use the ff package so, obviously I'm missing something
If any of you knows how to solve this, please teach me.
Thank you so much.
Lucas.
[[alternative HTML version deleted]]
2010 Jan 07
1
A question about the ff package
...d 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( vmode='logical', length=N, update=FALSE)
for (i in chunk(bigData, from=1, to=N, by=1e5))
select[i] <- ifelse(bigData[i,]$C.2 > 0.5, TRUE, FALSE)
bd <- bigData[select,]
Error in UseMethod("as.hi") :
no applicable method for 'as.hi' applied to an object of class...
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 needed
In addition: Warning message:
In bbatch(n, as.integer(BATCHBYTES/theobytes)) : NAs introduced by coercion
I'm not really sure that it...
2012 Sep 12
1
unzipping with ff
...lename is incorrect. First,
does anyone know of an unzip utility that works with ff or am I doing
something wrong there? Second, why does ff seem to add .Rdata and .ffData
when looking for files but adds no extension when saving them? Code
below...
library('ff')
ffcolTest = ff(c(1:500), vmode = "integer", length = 500, filename = <some
folder>\\ffTest')
quit()
library('ff')
ffload("<same path as above>")
Error in readChar(con, 5L, useBytes = TRUE) : cannot open the connection
In addition: Warning messages:
1: running command 'unzip -Z -...
2010 Dec 24
1
How to specify ff object filepaths when reading a CSV file into a ff data frame.
...ol3 to D:/a.f,D:/b.f,D:/c.f respectively
fdf <- read.csv.ffdf(file="D:/rtemp/fftest.csv",asffdf_args = list(
col_args = c(list(filename="D:/a.f"), list(filename="D:/b.f"),
list(filename="D:/c.f"))))
and the error message is :
Error in as.ff.default(1:2, vmode = NULL, filename = "D:/a.f",
filename = "D:/b.f", :
formal argument "filename" matched by multiple actual arguments
I also tried the following:
> fdf <- read.csv.ffdf(file="D:/rtemp/fftest.csv",asffdf_args = list( col_args = list(filename=c("...
2009 Nov 10
3
Error: cannot allocate vector of size...
I'm trying to import a table into R the file is about 700MB. Here's my first
try:
> DD<-read.table("01uklicsam-20070301.dat",header=TRUE)
Error: cannot allocate vector of size 15.6 Mb
In addition: Warning messages:
1: In scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
Reached total allocation of 1535Mb: see help(memory.size)
2: In scan(file, what,
2009 Nov 06
0
New version of package ff
...ing 1 mio rows: csv = 32.7 ffdf = 1.3
sequential writing 1 mio rows: csv = 35.5 ffdf = 1.5
Examples of things you can do with ff and bit:
- direct random access to rows of large data-frame instead of talking to SQL database (?ffdf)
- store 4-level factor like A,T,G,C with 2bit instead of 32bit (?vmode)
- fast chunked iteration (?chunk)
- run linear model on large dataset using biglm (?chunk.ffdf)
- handle boolean selections by factor 32 faster and less RAM consuming (?bit)
- handle very skewed selections very fast (?bitwhich)
- parallel access to large dataset just by sending ff's small meta...
2009 Nov 06
0
New version of package ff
...ing 1 mio rows: csv = 32.7 ffdf = 1.3
sequential writing 1 mio rows: csv = 35.5 ffdf = 1.5
Examples of things you can do with ff and bit:
- direct random access to rows of large data-frame instead of talking to SQL database (?ffdf)
- store 4-level factor like A,T,G,C with 2bit instead of 32bit (?vmode)
- fast chunked iteration (?chunk)
- run linear model on large dataset using biglm (?chunk.ffdf)
- handle boolean selections by factor 32 faster and less RAM consuming (?bit)
- handle very skewed selections very fast (?bitwhich)
- parallel access to large dataset just by sending ff's small meta...
2010 Oct 01
0
ff version 2.2.0
...idea to reduce
'ffmaxbytes' on slaves or avoid ff sorting there completely.
o New generic 'pagesize' with method 'pagesize.ff' which returns the
current pagesize as defined on opening the ff object.
USER VISIBLE CHANGES
o [.ff now returns with the same vmode as the ff-object
o Certain operations are faster now because we worked around
unnecessary copying triggered by many of R's assignment functions.
For example reading a factor from a (well-cached) file is now 20%
faster and thus as fast as just creating this factor in-RAM usin...
2010 Oct 01
0
ff version 2.2.0
...idea to reduce
'ffmaxbytes' on slaves or avoid ff sorting there completely.
o New generic 'pagesize' with method 'pagesize.ff' which returns the
current pagesize as defined on opening the ff object.
USER VISIBLE CHANGES
o [.ff now returns with the same vmode as the ff-object
o Certain operations are faster now because we worked around
unnecessary copying triggered by many of R's assignment functions.
For example reading a factor from a (well-cached) file is now 20%
faster and thus as fast as just creating this factor in-RAM usin...
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
2010 Apr 13
2
how to work with big matrices and the ff-package?
...ully someone can help me either with the ff-package or a different solution.
I am saving some calculated matrices as ff-objects as follows:
require(ff)
nr <- 117; nc <- 50
dat <- sample(0:100, size=(nr*nc), replace=TRUE)
a <- matrix(dat, nrow=nr)
ncols <- (nc*(nc-1))/2
b <- ff(vmode="double", dim=c(nr, ncols))
namb <- vector(mode="character", length=ncols)
x <- 1
for(i in 1:(nc-1)){
for(j in (i+1):nc){
b[,x] <- a[,i]+a[,j]
namb[x] <- paste(i, "_", j, sep="")
x <- x+1
}
}
dimnames(b)[[2]] <- namb
After the above...