# Re: [R] How do I make this faster?

From: Andreas Borg <andreas.borg_at_unimedizin-mainz.de>
Date: Mon, 11 Apr 2011 10:28:55 +0200

I'd be happy to help you, but I am not able to run your code. You use commandArgs to retrieve arguments of the R program, but which ones do you actually provide?

Best regards,

Andreas

Hasan Diwan schrieb:
> I was on vacation the last week and wrote some code to run a 500-day
> correlation between the Nasdaq tracking stock (QQQ) and 191 currency pairs
> for 500 days. The initial run took 9 hours(!) and I'd like to make it
> faster. So, I'm including my code below, in hopes that somebody will be able
> to figure out how to make it faster, either through parallelisation, or by
> making changes. I've marked the places where Rprof showed me it was slowing
> down:
> currencyCorrelation <- function(lagtime = 1) {
> require(quantmod)
>
> dataTrack <- getSymbols(commandArgs(trailingOnly=T)[1], from='2009-11-21',
> to='2011-04-03')
> stockData <- get(dataTrack)
> currencies <- row.names(oanda.currencies[grep(pattern='oz.', fixed=T, x
> =as.vector(oanda.currencies\$oanda.df.1.length.oanda.df...2....1.)) == F])
> correlations <- vector()
> values <- list()
> # optimise these loops using the apply family
> for (i in currencies) {
> for (j in currencies) {
> if (i == j) next()
> fx <- getFX(paste(i, j, sep='/'), from='2009-11-20', to='2011-04-02')
> # Prepare data by getting rates for market days only
> fx <- get(fx)
> fx <- fx[which(index(fx) %in% index(QQQ\$QQQ.Close))]
> correlation <- cor(fx, QQQ\$QQQ.Close)
> correlations <- c(correlations, correlation)
> string <- paste(paste(i,j,sep='/'), correlation, sep=',')
> values <- c(values,paste(string,'\n', sep=''))
> }
> }
> # TODO eliminate NA's
> values <- values[which(correlations[is.na(correlations) == F])]

> correlations <- correlations[is.na(correlations) == F]
> values <- values[order(correlations, decreasing=T)]
> write.table(values, file=commandArgs(trailingOnly=T)[2], sep='',
> qmethod=NULL, quote = F, row.names=F, col.names=F)
> rm('currencies', 'correlations', 'values', 'fx', 'string')
> return()
> }
> lagtime <- as.integer(commandArgs(trailingOnly=T)[3])
> if (is.na(lagtime)) lagtime <- 1
> print(paste(Sys.time(), '<--- starting', lagtime, 'day lag currencies
> correlation with', commandArgs(trailingOnly=T)[1], 'from 2009-11-20 to
> 2011-04-03'))
> currencyCorrelation(lagtime)
> print(paste(Sys.time(), '<--- ended, results in',
> commandArgs(trailingOnly=T)[2]))
>
>
>

```--
Andreas Borg
Medizinische Informatik

UNIVERSITÄTSMEDIZIN
der Johannes Gutenberg-Universität
Institut für Medizinische Biometrie, Epidemiologie und Informatik
Obere Zahlbacher Straße 69, 55131 Mainz
www.imbei.uni-mainz.de

Telefon +49 (0) 6131 175062
E-Mail: borg_at_imbei.uni-mainz.de

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