[R] reshape

jim holtman jholtman at gmail.com
Thu Jun 21 01:58:44 CEST 2012


Something got lost in the transmission since the '\\' were replaced
with '\'  I will try gain with the data: (also attached as a text
file)


require(reshape2)
 toy <- data.frame(year = rep(2007:2008,each = 20), month =
rep(1:5,each = 4, length = 40),
 day = rep(1:2,each = 2,length = 40), hhmm = rep(1100:1101,length =
40), plot = rep(1,40),
 trt=rep(4,40), VWC.B1 = rnorm(40), VWC.B2 = rnorm(40), VWC.T1 = rnorm(40),
 VWC.T2 = rnorm(40), VWC.T10 = rnorm(40), Tair.B1 = rnorm(40),Tair.B2=
rnorm(40),
 Tair.T1 = rnorm(40), Tair.T2 = rnorm(40))

 x <- melt(toy, id = c('year', 'month', 'day', 'hhmm', 'plot', 'trt'))

 # parse the type, group and number
 x$type <- sub("\\..*$", "", x$variable)
 x$group <- sub(".*\\.(.).*", "\\1", x$variable)
 x$number <- sub(".*\\..", "", x$variable)

 head(x)



On Wed, Jun 20, 2012 at 4:08 PM, nrm2010 <nrm2010 at zoho.com> wrote:
> Still working on it...to get your original suggestion to run,
> I "escaped" (doubled) the backslashes, so instead of
> x$type <- sub("\..*$", "", x$variable)
> which generated the error message
> Error: '\.' is an unrecognized escape in character string starting "\."
> I tried
> x$type <- sub("\\..*$", "", x$variable)
>
> That did not generate the error message and allowed me to
> run your second suggestion:
> dcast(x, year+month+day+hhmm+group+number ~ type, mean)
> The Tair and VWC columns appeared but the groups all came out as \001, instead of B or T.
>    year month day hhmm group number         Tair          VWC
> 1   2007     1   1 1100  \001      1  1.553844979  0.325459714
> 2   2007     1   1 1100  \001     10          NaN -0.693606661
>
>
> I'm also not trying to take the mean, but only to reformat from wide to long,
> so I tried it without the "mean" at the end of the dcast statement:
> dcast(x, year+month+day+hhmm+group+number ~ type)
> That resulted in a loss of the measurement data -
> the VWC and Tair columns are still there but they contain only 0's, 1's, or 2's.
>
>   year month day hhmm group number Tair VWC
> 1   2007     1   1 1100  \001      1    2   2
> 2   2007     1   1 1100  \001     10    0   1
> 3   2007     1   1 1100  \001      2    2   2
>
> So, I'm still working on it...
>
> Thanks,
>
> Toby
>
> R v. 2.15.0
> Windows OS
>
>
>
>
>
>
> ---- On Wed, 20 Jun 2012 09:51:45 -0700 jim holtman <jholtman at gmail.com> wrote ----
>  > Is this closer using the same data:
>  >
>  > > dcast(x, year+month+day+hhmm+group+number ~ type, mean)
>  >     year month day hhmm group number         Tair           VWC
>  > 1   2007     1   1 1100     B      1  0.285404913  1.4337114478
>  > 2   2007     1   1 1100     B      2 -0.899893189  1.1004122756
>  > 3   2007     1   1 1100     T      1 -0.054938988  0.0565570314
>  > 4   2007     1   1 1100     T     10          NaN -0.4645357924
>  > 5   2007     1   1 1100     T      2  0.235724005  0.1355795323
>  > 6   2007     1   1 1101     B      1  0.008141599  0.2010562273
>  > 7   2007     1   1 1101     B      2 -0.094439009  0.7713080532
>  > 8   2007     1   1 1101     T      1  1.111981883 -0.5022737361
>  > 9   2007     1   1 1101     T     10          NaN  0.3061178598
>  > 10  2007     1   1 1101     T      2  0.101879382 -0.1886613029
>  > 11  2007     1   2 1100     B      1 -2.189530590  0.0741563102
>  > 12  2007     1   2 1100     B      2  0.290204966  1.4341878509
>  > 13  2007     1   2 1100     T      1  0.788716089  1.9156394486
>  > 14  2007     1   2 1100     T     10          NaN  1.9814202666
>  > 15  2007     1   2 1100     T      2  0.255978008  0.0604626563
>  > 16  2007     1   2 1101     B      1 -0.479254067  0.7770438119
>  > 17  2007     1   2 1101     B      2  0.526466448 -0.1691557783
>  > 18  2007     1   2 1101     T      1  2.070198634  0.1129769772
>  > 19  2007     1   2 1101     T     10          NaN  1.5263077972
>  > 20  2007     1   2 1101     T      2 -0.883571883 -0.5357702486
>  >
>  >
>  > On Wed, Jun 20, 2012 at 12:33 PM, nrm2010 <nrm2010 at zoho.com> wrote:
>  > >
>  > > Thank you, but it doesn't quite.  It still needs a new column for each measurement type,
>  > > i.e., a VWC column that contains the VWC measurements for each subject within
>  > > group at each time point and a Tair column that contains the
>  > > Tair measurements for each subject within group at each time point.
>  > >
>  > > Toby
>  > >
>  > >
>  > >
>  > >
>  > > ---- On Wed, 20 Jun 2012 09:25:08 -0700 jim holtman  wrote ----
>  > >
>  > >>will this do it for you:
>  > >>
>  > >>
>  > >>> require(reshape2)
>  > >>> toy <- data.frame(year = rep(2007:2008,each = 20), month = rep(1:5,each = 4, length = 40),
>  > >>+ day = rep(1:2,each = 2,length = 40), hhmm = rep(1100:1101,length =
>  > >>40), plot = rep(1,40),
>  > >>+ trt=rep(4,40), VWC.B1 = rnorm(40), VWC.B2 = rnorm(40), VWC.T1 = rnorm(40),
>  > >>+ VWC.T2 = rnorm(40), VWC.T10 = rnorm(40), Tair.B1 = rnorm(40),Tair.B2
>  > >>= rnorm(40),
>  > >>+ Tair.T1 = rnorm(40), Tair.T2 = rnorm(40))
>  > >>>
>  > >>> x <- melt(toy, id = c('year', 'month', 'day', 'hhmm', 'plot', 'trt'))
>  > >>>
>  > >>> # parse the type, group and number
>  > >>> x$type <- sub("\..*$", "", x$variable)
>  > >>> x$group <- sub(".*\.(.).*", "\1", x$variable)
>  > >>> x$number <- sub(".*\..", "", x$variable)
>  > >>>
>  > >>> head(x)
>  > >> year month day hhmm plot trt variable value type group number
>  > >>1 2007 1 1 1100 1 4 VWC.B1 0.35680152 VWC B 1
>  > >>2 2007 1 1 1101 1 4 VWC.B1 -0.01787670 VWC B 1
>  > >>3 2007 1 2 1100 1 4 VWC.B1 -0.07361414 VWC B 1
>  > >>4 2007 1 2 1101 1 4 VWC.B1 0.90117558 VWC B 1
>  > >>5 2007 2 1 1100 1 4 VWC.B1 0.64824677 VWC B 1
>  > >>6 2007 2 1 1101 1 4 VWC.B1 0.26769079 VWC B 1
>  > >>>
>  > >>
>  > >>
>  > >>On Wed, Jun 20, 2012 at 12:08 PM, nrm2010  wrote:
>  > >>> Hello, helpeRs,
>  > >>>
>  > >>> I am attempting to reshape (either base R or package reshape) multiple .csv
>  > >>> spreadsheets from a very unfortunate wide format to long format.  Each spreadsheet
>  > >>> looks something like this, after being read in to R:
>  > >>>
>  > >>> toy <- data.frame(year = rep(2007:2008,each = 20), month = rep(1:5,each = 4, length = 40),
>  > >>> day = rep(1:2,each = 2,length = 40), hhmm = rep(1100:1101,length = 40), plot = rep(1,40),
>  > >>> trt=rep(4,40), VWC.B1 = rnorm(40), VWC.B2 = rnorm(40), VWC.T1 = rnorm(40),
>  > >>> VWC.T2 = rnorm(40), VWC.T10 = rnorm(40), Tair.B1 = rnorm(40),Tair.B2 = rnorm(40),
>  > >>> Tair.T1 =  rnorm(40), Tair.T2 = rnorm(40))
>  > >>>
>  > >>> Taken together, the columns year, month, day, and hhmm define a timepoint
>  > >>> at which at a measurement was taken.  Plot and treatment do not change within
>  > >>> any one spreadsheet.  Parsing the column names, VWC and Tair are 2 different
>  > >>> types of measurements; in the full dataset, there are more than 2 types of
>  > >>> measurements.  The B and T in the column names are grouping variables.  The
>  > >>> numbers following the B or T are subjects within groups.  So, if a column name
>  > >>> is VWC.B1, it is the VWC measurement taken on subject 1 within group B.
>  > >>>
>  > >>> I am trying to reshape to long format. The long format should have one new column
>  > >>> for each measurement type (VWC and Tair in the toy example), a new column
>  > >>> indicating the grouping variable (B or T), and a new column identifyng the
>  > >>> subject (the number that follow the B or T). I've been unable to come up with
>  > >>> a solution that produces the group and subject within group columns as well
>  > >>> as both types of measurements.
>  > >>>
>  > >>> Any assistance would be greatly appreciated.
>  > >>>
>  > >>> Thank you.
>  > >>>
>  > >>> Toby
>  > >>>
>  > >>> Toby Gass, Ph.D.
>  > >>> Visiting Lecturer, Forestry and Wildland Resources
>  > >>> Humboldt State University
>  > >>> email: toby.gass  humboldt  edu
>  > >>>
>  > >>> ______________________________________________
>  > >>> 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.
>  > >>
>  > >>
>  > >>
>  > >>--
>  > >>Jim Holtman
>  > >>Data Munger Guru
>  > >>
>  > >>What is the problem that you are trying to solve?
>  > >>Tell me what you want to do, not how you want to do it.
>  > >>
>  > >
>  >
>  >
>  >
>  > --
>  > Jim Holtman
>  > Data Munger Guru
>  >
>  > What is the problem that you are trying to solve?
>  > Tell me what you want to do, not how you want to do it.
>  >
>  >
>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.
-------------- next part --------------
 require(reshape2)
 toy <- data.frame(year = rep(2007:2008,each = 20), month = rep(1:5,each = 4, length = 40),
 day = rep(1:2,each = 2,length = 40), hhmm = rep(1100:1101,length = 40), plot = rep(1,40),
 trt=rep(4,40), VWC.B1 = rnorm(40), VWC.B2 = rnorm(40), VWC.T1 = rnorm(40),
 VWC.T2 = rnorm(40), VWC.T10 = rnorm(40), Tair.B1 = rnorm(40),Tair.B2= rnorm(40),
 Tair.T1 = rnorm(40), Tair.T2 = rnorm(40))

 x <- melt(toy, id = c('year', 'month', 'day', 'hhmm', 'plot', 'trt'))

 # parse the type, group and number
 x$type <- sub("\\..*$", "", x$variable)
 x$group <- sub(".*\\.(.).*", "\\1", x$variable)
 x$number <- sub(".*\\..", "", x$variable)

 head(x)


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