similar to: non-integer key for data.table

Hi all, I am just wondering if there is a more efficient way of merging two large datasets based on the values of multiple columns, some of which are not numerical. The default merge function in dataframe is very inefficient and the merge function in data.table seems to be faster, but it does not seem to allow keys that are not numerical in nature. Any other suggestion? Thanks a lot!

Hi all, Thanks a lot for anyone's help in advance. I am trying to find a way to compute the day-to-day return (log return) from a n x r matrix containing, n different stocks and price quotes over r days. The time series of prices are already split by using unstack function. For the result, I would like to see a n x (r-1) matrix, where by each entry is the day-over-day return of

Hello All Have 2 tables dt1: start end kwh10min 2013-04-01 00:00:54 UTC 2013-04-01 01:00:10 UTC 0.05 2013-04-01 00:40:26 UTC 2013-04-01 00:50:00 UTC 0.1 2013-04-01 02:13:20 UTC 2013-04-01 04:53:42 UTC 0.15 2013-04-02 02:22:00 UTC 2013-04-01 04:33:12 UTC 0.2 2013-04-01 02:26:23 UTC 2013-04-01 04:05:12 UTC 0.25 2013-04-01 02:42:47 UTC 2013-04-01 04:34:33 UTC 0.3 2013-04-01 02:53:12 UTC 2013-04-03

Hi, Just wondering for the SMA and EMA in package TTR, is it possible to me to code it so that, say if I need to calculate SMA (x, n=100), when the sample size is less than 100, it will give me the SMA (x, k) where k is the sample size of the data? Right now it only gives me an invalid n error. Thanks! [[alternative HTML version deleted]]

I've two data.tables as shown below: *** N = 10 A.DT <- data.table(a1 = c(rnorm(N,0,1)), a2 = NA)) B.DT <- data.table(b1 = c(rnorm(N,0,1)), b2 = 1:N) setkey(A.DT,a1) setkey(B.DT,b1) *** I tried to change my previous data.frame implementation to a data.table implementation by changing the for-loop as shown below: *** for (i in 1:nrow(B.DT)) { for (j in nrow(A.DT):1) { if

Hi, I have a question about how to obtain the union of several data frame rows. I'm trying to create a common key for several tests composed of different items. Here is a small scale version of the problem. These are keys for 4 different tests, not all mutually exclusive: id q1 q2 q3 q4 q5 q6 1 A C 2 B D 3 A D B 4 C D B D I would like

dear r experts---Is there a multicore equivalent of by(), just like mclapply() is the multicore equivalent of lapply()? if not, is there a fast way to convert a data.table into a list based on a column that lapply and mclapply can consume? advice appreciated...as always. regards, /iaw ---- Ivo Welch (ivo.welch at gmail.com)

Hi, I have a class ''Menu'' with a method ''addItem''. The method (simplified) looks like this: addItem: function(itemId, text) { this.container.innerHTML += ''<div id="''+itemId+''">''+text+''</div>''; Event.observe(itemId, ''mouseover'',

Apologies if this is an obvious question but I am teaching myself R and the occasional push in the right direction is much appreciated? I have a data.frame containing data that looks like this CustID itemID 1 a 1 b 2 c 3 a 3 c I want to assemble the vector of all the items bought by a particular customer and can't quite see how to do it. What is the best

Hi, Could not conceive an working set-up for an IPSEC VPN made with racoon/setkey on which I have one address on my side acting as an SNAT router for all traffic from my network to a network segment on the far side. my network --- my gateway ---------------------- remote network 10.0.0.0/24 - 10.0.0.1 (10.253.0.2) -- tunnel - 192.168.0.0/22 All traffic starts on my side, so if I can

Hi, i''m going to implement a syndication-service, which will get lists in xml with some meta-data an enclosed video files, which will get encoded at the end. The syndication run will be startet every five minutes of a full hour. So i thought to build 4 Worker. One for checking which feeds to syndicate (syndication_worker) at a specific time, one for processing the list

Whoever is responsible for updating vorbis.com, I think it's about time the old and outdated Tobias DirectShow filters were removed from the Windows section and replaced with http://www.illiminable.com/ogg. This supports playing Ogg Vorbis, Ogg Speex, Ogg Theora, Ogg FLAC and native FLAC in Windows. The following website should also be updated but I'm not sure who submitted it.

Hello all, I am trying to figure out an optimal linear model by using stepwise regression which requires partial f-test, I did some Googling on the Internet and realised that someone seemed to ask the question before: Jim Milks <jrclmilks at joimail.com> writes: > Dear all: > > I have a regression model that has collinearity problems (between > three regressor variables). I

> -----Original Message----- > From: Greg Panula [mailto:greg.panula@dolaninformation.com] > Sent: 12 May 2003 11:10 > To: Matthew Braithwaite > Cc: stable@freebsd.org > Subject: Re: iHEADS UP: ipsec packet filtering change > > You don't really need the gif tunnels for ipsec. Gif is more geared > towards ipv4 <=> ipv6 type tunnels. A few of ipsec

Hey All, So - I promise to write a blog post on this topic and post it somewhere on the internet once I get to the bottom of this. Basically, the set-up to the problem is like this: 1. I have a data frame with dim (2547290, 4) 2. I need to make SQL like lookups on the dataframe. I have been using the following sort of syntax: a.dataframe[a.dataframe[[column_index]] %in% some_value, ] 3.

Hi, When a IPSec tunnel is established between two peers, I understand that the "normal" situation is to have in a given moment two SAs, one for each direction of the tunnel. However, in one of my tunnels (peer P1 running GNU/Linux with setkey and racoon; peer P2 is a Cisco router) there is a large number (around 19) of SAs established (this has been observed in P1 with

Hola, quiero compartir con vosotros mi problema y la solución que me han planteado. Mi programa carga Outcomes.csv y Set-A.csv (descargados de http://garrickadenbuie.com/blog/2013/04/11/visualize-physionet-data-with-r/, apartado Getting Started --> the code and the data set) de unos 50MB entre los dos. Mi código era: # Transforma csv a data frame seta <- read.csv('Set-A.csv');

Eric ¿Que dataset utilizo? Por curiosidad probé su código, pero me salen errores. Copio y pego todo como me sale en la consola. > # https://raw.githubusercontent.com/datasets/covid-19/master/data/time-series-19-covid-combined.csv > datos <- read.csv("C:/Users/HP/Downloads/time-series-19-covid-combined.csv") > > library(data.table) > library(ggplot2) >

I have a dataset of property transactions that includes the transaction ID (TranID), property ID (UnitID), and transaction date (TranDt). I need to create a data frame (or data table) that includes the previous transaction date, if one exists. This is an easy problem in SQL, where I just run a sub-query, but I'm trying to make R my one-stop-shopping program. ?The following code works on a

Hi everyone, First of all, this is my first post in this ML, so I''m not sure that this is the right place for my question (please don''t shoot me down ;)). For the record, I''ve been reading and using LARTC for almost 3 years now, and it''s a great help for anyone who wants to learn linux networking. My problem: I want to setup a tunnel for the following