[R] reshape

[nrm2010]

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 
>> 
>> ______________________________________________ 
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>> 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. 
>