Dear All,
I am trying to analysis traffic data with one timestamp column and speed
column. This data set contains six years data; for each year, I want to make
a matrix in (day of the year) * (hour)
0 1 2 . . . 23
1
2
.
.
365
However random day's record is missing(e.g. there are 40 missing records in
2005 data set), when I tried to use tapply function, matrix came out is
326*23 table and there were no N/A remind me which day is missing data.
Can you give some hints to make a 366*24 table please? Any help is
appreciated.
Jessica
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On Jul 7, 2011, at 3:21 PM, xin123620 wrote:> Dear All, > > I am trying to analysis traffic data with one timestamp column and > speed > column. This data set contains six years data; for each year, I want > to make > a matrix in (day of the year) * (hour) > 0 1 2 . . . 23 > 1 > 2 > . > . > 365 > > However random day's record is missing(e.g. there are 40 missing > records in > 2005 data set), when I tried to use tapply function, matrix came out > is > 326*23 table and there were no N/A remind me which day is missing > data. > > Can you give some hints to make a 366*24 table please? Any help is > appreciated.More detail about what your data looks like and how you are importing it from file would be helpful. (And please do read the Posting Guide where this request is spelled out in greater detail and where advice about successful attachment of datasets can be found.)> > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.-- David Winsemius, MD West Hartford, CT
Make factors out of the dayOfYear and HourOfDay columns and specify the levels you want. Then pass the factors to tapply. E.g., you may have something like> d <- data.frame(Season=c(1,1,3,4),Type=c(20,15,15,20), Speed=11:14)> tapply(d$Speed, d[c("Season","Type")], mean)Type Season 15 20 1 12 11 3 13 NA 4 NA 14 and you are missing the row for Season==2 and perhaps for some of the types. Making factors out of Season and Type (with the desired levels) lets you get the missing rows and columns in the output of tapply:> d$Season <- factor(d$Season, levels=c(1,2,3,4)) > d$Type <- factor(d$Type, levels=c(5,10,15,20)) > tapply(d$Speed, d[c("Season","Type")], mean)Type Season 5 10 15 20 1 NA NA 12 11 2 NA NA NA NA 3 NA NA 13 NA 4 NA NA NA 14 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org > [mailto:r-help-bounces at r-project.org] On Behalf Of xin123620 > Sent: Thursday, July 07, 2011 12:21 PM > To: r-help at r-project.org > Subject: [R] How to make matrix missing data 0 > > Dear All, > > I am trying to analysis traffic data with one timestamp > column and speed > column. This data set contains six years data; for each year, > I want to make > a matrix in (day of the year) * (hour) > 0 1 2 . . . 23 > 1 > 2 > . > . > 365 > > However random day's record is missing(e.g. there are 40 > missing records in > 2005 data set), when I tried to use tapply function, matrix > came out is > 326*23 table and there were no N/A remind me which day is > missing data. > > Can you give some hints to make a 366*24 table please? Any help is > appreciated. > > Jessica > > > -- > View this message in context: > http://r.789695.n4.nabble.com/How-to-make-matrix-missing-data-0-tp3652352p3652352.html> Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >
Thank you William!!!! Your method does work!!!! I highly appreciate that. :D Also thank you for replying, David. You are absolutely correct. I re-edited my posting to make question clear according to the guidelines in case other person meet the similar problem as I have. Thank you, Jessica -- View this message in context: http://r.789695.n4.nabble.com/How-to-make-matrix-missing-data-0-tp3652352p3652432.html Sent from the R help mailing list archive at Nabble.com.