Thanks Hadley for Your interest, below some code without environments use (using timeSeries); I also made some experiments with .parallel = TRUE in daply to crate timeSeries objects and then bind them together but I have some problems.
Thank You in advance, Daniele Amberti set.seed(123) N <- 10000 X <- data.frame( ID = c(rep(1,N), rep(2,N,), rep(3,N), rep(4,N)), DATE = as.character(rep(as.POSIXct("2000-01-01", tz = "GMT")+ 0:(N-1), 4)), VALUE = runif(N*4), stringsAsFactors = FALSE) X <- X[sample(1:(N*4), N*4),] str(X) head(X) #define a variable in global env ATS <- NULL buildTimeSeriesFromDataFrame <- function(x) { library(timeSeries) if(!is.null(ATS)) # in global env { # assign in global env ATS <<- cbind(ATS, timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d %H:%M:%S', zone = 'GMT', units = as.character(x$ID[1]))) } else { # assign in global env ATS <<- timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d %H:%M:%S', zone = 'GMT', units = as.character(x$ID[1])) } return(TRUE) } tsDaply <- function(...) { # assign in global env, to clean previous run ATS <<- NULL library(plyr) res <- daply(X, "ID", buildTimeSeriesFromDataFrame) return(res) } tsDaply(X, X$ID) head(ATS) #performance tests Time <- replicate(100, system.time(tsDaply(X, X$ID))[[1]]) median(Time) hist(Time) ### #some multithread tests: ### library(doSMP) w <- startWorkers(workerCount = 2) registerDoSMP(w) # do not cbint ts, just create buildTimeSeriesFromDataFrame2 <- function(x) { library(timeSeries ) xx <- timeSeries:::timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d %H:%M:%S', zone = 'GMT', units = as.character(x$ID[1])) return(xx) } #tsDaply2 <- function(...) #{ # library(plyr) # res <- daply(X, "ID", buildTimeSeriesFromDataFrame2, .parallel = TRUE) # return(res) #} # tsDaply2 .parallel = TRUE return error: #Error in do.ply(i) : task 4 failed - "subscript out of bounds" #In addition: Warning messages: #1: <anonymous>: ... may be used in an incorrect context: '.fun(piece, ...)' #2: <anonymous>: ... may be used in an incorrect context: '.fun(piece, ...)' tsDaply2 <- function(...) { library(plyr) res <- daply(X, "ID", buildTimeSeriesFromDataFrame2, .parallel = FALSE) return(res) } # tsDaply2 .parallel = FALSE work but list discart timeSeries class # bind after ts creation res <- tsDaply2(X, X$ID) # list is not a timeSeries object str(cbind(t(res))) res <- as.timeSeries(cbind(t(res))) stopWorkers(w) -----Original Message----- From: h.wick...@gmail.com [mailto:h.wick...@gmail.com] On Behalf Of Hadley Wickham Sent: 14 March 2011 12:48 To: Daniele Amberti Cc: r-help@r-project.org Subject: Re: [R] dataframe to a timeseries object - [ ] Message is from an unknown sender Well, I'd start by removing all explicit use of environments, which makes you code very hard to follow. Hadley On Monday, March 14, 2011, Daniele Amberti <daniele.ambe...@ors.it> wrote: > I found that plyr:::daply is more efficient than base:::by (am I doing > something wrong?), below updated code for comparison (I also fixed a couple > things). > Function daply from plyr package has also a .parallel argument and I wonder > if creating timeseries objects in parallel and then combining them would be > faster (Windows XP platform); does someone has experience with this topic? I > found only very simple examples about plyr and parallel computations and I do > not have a working example for such kind of implementation (daply that return > a list of timeseries objects). > > Thanks in advance, > Daniele Amberti > > > set.seed(123) > > N <- 10000 > X <- data.frame( > ID = c(rep(1,N), rep(2,N,), rep(3,N), rep(4,N)), > DATE = as.character(rep(as.POSIXct("2000-01-01", tz = "GMT")+ 0:(N-1), 4)), > VALUE = runif(N*4), stringsAsFactors = FALSE) > X <- X[sample(1:(N*4), N*4),] > str(X) > > library(timeSeries) > buildTimeSeriesFromDataFrame <- function(x, env) > { > { > if(exists("xx", envir = env)) > assign("xx", > cbind(get("xx", env), timeSeries(x$VALUE, x$DATE, > format = '%Y-%m-%d %H:%M:%S', > zone = 'GMT', units = as.character(x$ID[1]))), > envir = env) > else > assign("xx", > timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d %H:%M:%S', > zone = 'GMT', units = as.character(x$ID[1])), > envir = env) > > return(TRUE) > } > } > > tsBy <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- by(X, X$ID, buildTimeSeriesFromDataFrame, > env = e1, simplify = TRUE) > return(get("xx", e1)) > } > > Time01 <- replicate(100, > system.time(tsBy(X, X$ID, simplify = TRUE))[[1]]) > median(Time01) > hist(Time01) > ATS <- tsBy(X, X$ID, simplify = TRUE) > > > library(xts) > buildXtsFromDataFrame <- function(x, env) > { > { > if(exists("xx", envir = env)) > assign("xx", > cbind(get("xx", env), xts(x$VALUE, > as.POSIXct(x$DATE, tz = "GMT", > format = '%Y-%m-%d %H:%M:%S'), > tzone = 'GMT')), > envir = env) > else > assign("xx", > xts(x$VALUE, as.POSIXct(x$DATE, tz = "GMT", > format = '%Y-%m-%d %H:%M:%S'), > tzone = 'GMT'), > envir = env) > > return(TRUE) > } > } > > xtsBy <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- by(X, X$ID, buildXtsFromDataFrame, > env = e1, simplify = TRUE) > return(get("xx", e1)) > } > > Time02 <- replicate(100, > system.time(xtsBy(X, X$ID,simplify = TRUE))[[1]]) > median(Time02) > hist(Time02) > AXTS <- xtsBy(X, X$ID, simplify = TRUE) > > plot(density(Time02), col = "red", > xlim = c(min(c(Time02, Time01)), max(c(Time02, Time01)))) > lines(density(Time01), col = "blue") > #check equal, a still a problem with names > AXTS2 <- as.timeSeries(AXTS) > names(AXTS2) <- names(ATS) > identical(getDataPart(ATS), getDataPart(AXTS2)) > identical(time(ATS), time(AXTS2)) > > # with plyr library and daply instead of by: > library(plyr) > > tsDaply <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- daply(X, "ID", buildTimeSeriesFromDataFrame, > env = e1) > return(get("xx", e1)) > } > > Time03 <- replicate(100, > system.time(tsDaply(X, X$ID))[[1]]) > median(Time03) > hist(Time03) > > xtsDaply <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- daply(X, "ID", buildXtsFromDataFrame, > env = e1) > return(get("xx", e1)) > } > > Time04 <- replicate(100, > system.time(xtsDaply(X, X$ID))[[1]]) > > median(Time04) > hist(Time04) > > plot(density(Time04), col = "red", > xlim = c( > min(c(Time02, Time01, Time03, Time04)), > max(c(Time02, Time01, Time03, Time04))), > ylim = c(0,100)) > lines(density(Time03), col = "blue") > lines(density(Time02)) > lines(density(Time01)) > > > > > > -----Original Message----- > From: Daniele Amberti > Sent: 11 March 2011 14:44 > To: r-help@r-project.org > Subject: dataframe to a timeseries object > > I'm wondering which is the most efficient (time, than memory usage) way to > obtain a multivariate time series object from a data frame (the easiest data > structure to get data from a database trough RODBC). > I have a starting point using timeSeries or xts library (these libraries can > handle time zones), below you can find code to test. > Merging parallelization (cbind) is something I'm thinking at (suggestions > from users with experience on this topic is highly appreciated), any > suggestion is welcome. > My platform is Windows XP, R 2.12.1, latest available packages on CRAN for > timeSeries and xts. > > > set.seed(123) > > N <- 9000 > X <- data.frame( > ID = c(rep(1,N), rep(2,N,), rep(3,N), rep(4,N)), > DATE = rep(as.POSIXct("2000-01-01", tz = "GMT")+ 0:(N-1), 4), > VALUE = runif(N*4)) > > library(timeSeries) > buildTimeSeriesFromDataFrame <- function(x, env) > { > { > if(exists("xx", envir = env)) > assign("xx", > cbind(get("xx", env), timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d > %H:%M:%S', > zone = 'GMT', units = as.character(x$ID[1]))), > envir = env) > else > assign("xx", > timeSeries(x$VALUE, x$DATE, format = '%Y-%m-%d %H:%M:%S', > zone = 'GMT', units = as.character(x$ID[1])), > envir = env) > > return(TRUE) > } > } > > > fooBy <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- by(X, X$ID, buildTimeSeriesFromDataFrame, > env = e1, simplify = TRUE) > return(get("xx", e1)) > } > > Time01 <- replicate(100, > system.time(fooBy(X, > X$ID, buildTimeSeriesFromDataFrame, > simplify = TRUE))[[1]]) > > median(Time01) > hist(Time01) > > library(xts) > > buildXtsFromDataFrame <- function(x, env) > { > { > if(exists("xx", envir = env)) > assign("xx", > cbind(get("xx", env), xts(x$VALUE, > as.POSIXct(x$DATE, format = '%Y-%m-%d %H:%M:%S'), > tzone = 'GMT')), > envir = env) > else > assign("xx", > xts(x$VALUE, as.POSIXct(x$DATE, format = '%Y-%m-%d %H:%M:%S'), > tzone = 'GMT'), > envir = env) > > return(TRUE) > } > } > > fooBy <- function(...) > { > e1 <- new.env(parent = baseenv()) > res <- by(X, X$ID, buildXtsFromDataFrame, > env = e1, simplify = TRUE) > return(get("xx", e1)) > } > > Time02 <- replicate(100, > system.time(fooBy(X, > X$ID, buildTimeSeriesFromDataFrame, > simplify = TRUE))[[1]]) > > median(Time02) > hist(Time02) > > plot(density(Time02), xlim = c(min(c(Time02, Time01)), max(c(Time02, > Time01)))) > lines(density(Time01)) > > > Best regards, > Daniele Amberti > > ORS Srl > > Via Agostino Morando 1/3 12060 Roddi (Cn) - Italy > Tel. +39 0173 620211 > Fax. +39 0173 620299 / +39 0173 433111 > Web Site www.ors.it > > ------------------------------------------------------------------------------------------------------------------------ > Qualsiasi utilizzo non autorizzato del presente messaggio e dei suoi allegati > è vietato e potrebbe costituire reato. > Se lei avesse ricevuto erroneamente questo messaggio, Le saremmo grati se > provvedesse alla distruzione dello stesso > e degli eventuali allegati. > Opinioni, conclusioni o altre informazioni riportate nella e-mail, che non > siano relative alle attività e/o > alla missione aziendale di O.R.S. Srl si intendono non attribuibili alla > società stessa, né la impegnano in alcun modo. > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ / ORS Srl Via Agostino Morando 1/3 12060 Roddi (Cn) - Italy Tel. +39 0173 620211 Fax. +39 0173 620299 / +39 0173 433111 Web Site www.ors.it ------------------------------------------------------------------------------------------------------------------------ Qualsiasi utilizzo non autorizzato del presente messaggio e dei suoi allegati è vietato e potrebbe costituire reato. Se lei avesse ricevuto erroneamente questo messaggio, Le saremmo grati se provvedesse alla distruzione dello stesso e degli eventuali allegati. Opinioni, conclusioni o altre informazioni riportate nella e-mail, che non siano relative alle attività e/o alla missione aziendale di O.R.S. Srl si intendono non attribuibili alla società stessa, né la impegnano in alcun modo. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.