Hello, Thank you for response
I have try reshape function, but i do not like the way how it generate columns and row names. Currently > tapply(s$value, list(s$day, s$symbol), mean) seems to generate exactly what i need Cheers, Dima 2011/3/5 Uwe Ligges <lig...@statistik.tu-dortmund.de> > > > > On 04.03.2011 11:38, Dmitrij Kudriavcev wrote: > >> Hello >> >> Let's say, my data.frame is >> >> symbol,day,value >> A, 2010-01-01, 0.8888 >> A, 2010-01-02, 0.6666 >> B, 2010-01-01, 0.7777 >> >> i need to get matrix as >> > > > See ?reshape, in this case if you data.frame is in dat: > > reshape(dat, v.names="value", direction="wide", > idvar="day", timevar="symbol") > > Uwe Ligges > > > > > , A, B >> 2010-01-01, 0.8888, 0.7777 >> 2010-01-02, 0.6666, NA >> >> where A and B is columns name and date used as row name >> >> I found a way how to do it with tapply function, is it a best way (i will >> need to do this pretty offen and wish to save some time) >> >> Cheers, >> Dima >> >> >> 2011/3/4 Ivan Calandra<ivan.calan...@uni-hamburg.de> >> >> Hi, >>> >>> Let's say your data.frame is called df: >>> df<- data.frame(a=rnorm(10), b=rnorm(10)) >>> data.matrix<- as.matrix(df) >>> >>> This should work, but be careful with coercion if you have different >>> modes >>> in your data.frame >>> >>> HTH, >>> Ivan >>> >>> PS: next time, provide a reproducible example, using dput() for example >>> >>> Le 3/4/2011 07:08, Dmitrij Kudriavcev a écrit : >>> >>> Hello >>>> >>>> I'm a new in R >>>> I have a large data.frame "s" (this is actualy just a table in mysql) : >>>> >>>> names(s) >>>> >>>>> >>>>> [1] "symbols", "day", "value" >>>> >>>> I need to convert it to simple matrix. I have define this matrix like >>>> this: >>>> >>>> data.matrix<- matrix(nrow=nDays, ncol=nSymbols, dimnames=list(days, >>>> >>>>> >>>>> symbols)) >>>> >>>> then i just copy values to the matrix using for() loop, but it seems to >>>> take >>>> very long time. Is is a more fast way to do it in R? I know, what i can >>>> just >>>> gyve s$value as source data to the matrix, but problem is, what for some >>>> symbols couple days could be just missed. >>>> >>>> Cheers, >>>> Dima >>>> >>>> [[alternative HTML version deleted]] >>>> >>>> ______________________________________________ >>>> 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. >>>> >>>> >>>> -- >>> Ivan CALANDRA >>> PhD Student >>> University of Hamburg >>> Biozentrum Grindel und Zoologisches Museum >>> Abt. Säugetiere >>> Martin-Luther-King-Platz 3 >>> D-20146 Hamburg, GERMANY >>> +49(0)40 42838 6231 >>> ivan.calan...@uni-hamburg.de >>> >>> ********** >>> http://www.for771.uni-bonn.de >>> http://webapp5.rrz.uni-hamburg.de/mammals/eng/1525_8_1.php >>> >>> >>> ______________________________________________ >>> 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. >>> >>> >> [[alternative HTML version deleted]] >> >> >> >> >> ______________________________________________ >> 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. >> > [[alternative HTML version deleted]]
______________________________________________ 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.
