similar to: unknownR : you didn't know you didn't know?

data.table offers fast subset, fast grouping and fast ordered joins in a short and flexible syntax, for faster development. It was first released in August 2008 and is now the 3rd most popular package on Crantastic with 20 votes and 7 reviews. * X[Y] is a fast join for large data. * X[,sum(b*c),by=a] is fast aggregation. * 10+ times faster than tapply() * 100+ times faster than == It inherits

data.table offers fast subset, fast grouping and fast ordered joins in a short and flexible syntax, for faster development. It was first released in August 2008 and is now the 3rd most popular package on Crantastic with 20 votes and 7 reviews. * X[Y] is a fast join for large data. * X[,sum(b*c),by=a] is fast aggregation. * 10+ times faster than tapply() * 100+ times faster than == It inherits

Forwarded to R-Help, because I think it could interest people following this thread. Clearly, RServe and svSocket have different goals and very little overlap. Best, Philippe -------- Original Message -------- Subject: Re: Video demo of using svSocket with data.table Date: Wed, 26 Aug 2009 20:34:19 +0100 From: Matthew Dowle <mdowle at mdowle.plus.com> Reply-To: Matthew Dowle

Matthew Dowle wrote: > Hi, > > Try package 'data.table'. It has a concept of keys which allows you to do > exactly that. > > http://datatable.r-forge.r-project.org/ > > Matthew > > Hi Matthew, Unfortunately, the load of that library fails (it builds successfully). I'm currently looking into why. Error output looks something similar to: >

Hi, Please see below for post on r-help regarding data.frame() and the possibility of dropping rownames, for space and time reasons. I've made some changes, attached, and it seems to be working well. I see the expected space (90% saved) and time (10 times faster) savings. There are no doubt some bugs, and needs more work and testing, but I thought I would post first at this stage. Could some

Kurt, Uwe suggested I write to you as maintainer of chron ... at the start of is.weekend, in the check on the argument type, maybe just change chron() to as.chron()? This would ensure as.chron.POSIXt gets called on POSIXt arguments, and (I think) fixes the problem. I tested and it seems ok. No warning/error required. > is.weekend function(x) { if(!inherits(x, "dates"))

Hi all, Does anyone know a solution for this error ? > tkwidget(dlg, "iwidgets::spinint", range="{0 23}") Error in structure(.External("dotTclObjv", objv, PACKAGE = "tcltk"), class = "tclObj") : [tcl] wrong # args: should be ".31.1.19 configure -range {begin end}". Thanks, Matthew [[alternative HTML version

I've programmed a quick-and-dirty version of symlinks for smbfs. This hack uses the system attribute and otherwise works much like the ncpfs-hack, that is to say, I write the magic cookie at the beginning of the file. Of course the server has to map the system attribute, which samba notably doesn't do by default. smb.conf entries of "map system = yes" and "create mask =

Hi, Similar questions have come up before on the list and elsewhere but I haven't found a solution yet. winbuilder's install.out shows data.table's .c files compiled with -O3 on Win32 but -O2 on Win64. The same happens on R-Forge. I gather that some packages don't work with -O3 so the default is -O2. I've tried this in data.table's Makevars (entire contents) : ====

Dear R-devel, REvolution appear to be offering ParallelR only when bundled with their R Enterprise edition. As such it appears to be non-free and closed source. http://www.revolution-computing.com/products/parallel-r.php Since R is GPL and not LGPL, is this a breach of the GPL ? Below is the "GPL and ParallelR" thread from their R forum. mdowle > It appears that ParallelR

Hi, In the example below why is d 10 times bigger than m, according to object.size ? It also takes around 10 times as long to create, which fits with object.size() being truthful. gcinfo(TRUE) also indicates a great deal more garbage collector activity caused by data.frame() than matrix(). $ R --vanilla .... > nr = 1000000 > system.time(m<<-matrix(integer(1), nrow=nr, ncol=2)) [1]

I need to identify repeated items in p$a with different s and d entries on the same row, given that the "0" items should not be considered in the comparison. Here is an example: 1. Items 3 and 5 in p$a are repeated with different entries of s and d, should be removed. 2. Item 2 was repeated twice but with a 0 once for s on row 2 and a second time for d on row 6, hence 2 should be

Dear list, I received the response below from the package author of 'debug'. I post it to the list, with Mark's approval, in case it is useful to others too. Regards, Matthew -----Original Message----- From: Mark.Bravington at csiro.au [mailto:Mark.Bravington at csiro.au] Sent: 22 October 2006 23:53 To: Matthew Dowle Cc: Mark.Bravington at csiro.au Subject: RE: Debug package

Dear R experts, I have a Matlab code which I am translating to R in order to examine and enhance it. First of all, I need to reproduce in R the results which were already obtained in Matlab (to make sure that everything is correct). There are some matrix manipulations and '\' operation among them in the code. I have the following data frame > ABS.df Pro syn

Dear R-users, Is there a easy way to access to a complete listing of available functions from a R session? The help.start() and ? functions are great, but I feel like they require the user to know the answer in advance (especially with respect to function names)... I could not find a easy way to simply browse through a list of functions and randomly pick one function to see what is does. Is

Is it intended that the first suffix can no longer be blank? Seems to be caused by a bug fix to merge in R 2.15.0. $Rdevel --vanilla DF1 = data.frame(a=1:3,b=4:6) DF2 = data.frame(a=1:3,b=7:9) merge(DF1,DF2,by="a",suffixes=c("",".1")) Error in merge.data.frame(DF1, DF2, by = "a", suffixes = c("", ".1")) : there is already a column

Hi, n = 10000000 L = list(a=integer(n), b=integer(n)) L[[2]][1:10] gives me the first 10 items of the 2nd vector in the list L. It works fine. However it appears to copy the entire L[[2]] vector in memory first, before subsetting it. It seems reasonable that "[[" can't know that all that is to be done is to do [1:10] on the result and therefore a copy in memory of the entire

Under the "further resources" section I'd like to suggest the following addition : * http://crantastic.org/ lists popular packages according to other users votes. Consider briefly reviewing the top 30 packages before posting to r-help since someone may have already released a package that solves your problem. Thats just a straw man idea so I hope there will be answer, or

Hi, $ R --vanilla R version 2.14.1 (2011-12-22) Platform: i686-pc-linux-gnu (32-bit) > DF = data.frame(a=1:3,b=4:6) > DF a b 1 1 4 2 2 5 3 3 6 > tracemem(DF) [1] "<0x8898098>" > names(DF)[2]="B" tracemem[0x8898098 -> 0x8763e18]: tracemem[0x8763e18 -> 0x8766be8]: tracemem[0x8766be8 -> 0x8766b68]: > DF a B 1 1 4 2 2 5 3 3 6 > Are those 3

Hello, Regarding this in R-devel/NEWS/New features : o ?library(pkg)? no longer warns about a conflict with a function from ?package:base? if the function is an identical copy of the base one but with a different environment. Why would one want an identical copy in a different environment? I'm thinking I may be missing out on a trick here. Matthew