Re: [R] Proper Syntax for Logical Subset in Subset()
On Wed, 2 Nov 2011, Rich Shepard wrote: I want a subset of this with only 7 chemicals: Ca, Cl, Cond, Mg, Na, SO4, and TDS. I should have also written that what I ultimately want is to create a box-and-whisker plot for these 7 chemicals in a single panel. If that can be done directly from the source data frame without creating another subset, I want to learn the syntax for that. Rich __ 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.
Re: [R] Proper Syntax for Logical Subset in Subset()
I have measured values for 47 chemicals in a stream. After processing
the original data frame through reshape2, the recast data frame has this
structure:
'data.frame': 256 obs. of 47 variables:
$ site : Factor w/ 143 levels BC-0.5,BC-1,..: 1 1 1 2 2 2 2 2
2 2...
$ sampdate : Date, format: 1996-04-19 1996-05-21 ...
$ Acid : num NA NA NA NA NA NA NA NA NA NA ...
...
I want a subset of this with only 7 chemicals: Ca, Cl, Cond, Mg, Na,
SO4,
and TDS. The subset help page tells me that I can use a logical subset
to
extract these 7 rows while keeping all columns, but I do not know how to
write that logical subset.
Wow, I don't see how you wound up with the code you tried based on the
instructions. I guess for some of us the best instruction is a bloody
nose, myself often included.
It sounds like you want to get rid of some columns in the reshaped
dataframe, not rows.
new - old[c('site', 'Ca', 'Cl', 'Cond', 'Mg', 'Na', 'SO4', 'TDS')]
will work, as will the following if you insist on using the subset
function.
new - subset(old, c(site, Ca, Cl, Cond, Mg, Na, SO4, TDS))
If you actually want to get rid of rows that aren't the minerals of
interest, then work with your unreshaped dataframe:
new - subset(reallyOld, parameter in c('Ca', 'Cl', 'Cond', 'Mg', 'Na',
'SO4', 'TDS'))
--
Curt Seeliger, Data Ranger
Raytheon Information Services - Contractor to ORD
seeliger.c...@epa.gov
541/754-4638
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Proper Syntax for Logical Subset in Subset()
To make such a plot, I would have thought your want your data structure to be: yourdat: Column A: Date Column B; Chemical Column C: Result After subsetting this to the chemicals you want or doing the subsetting in your plot command, something like (base R) boxplot(Result ~ Chemical, subset=yourdat$Chemical %in% c(Ca,Cl, Cond,Mg,Na,SO2,TDS)) You probably can get what you want one way or the other with your current data structure -- though you may have to use ggplot or trellis -- but it does appear to be inconvenient. Whether I'm correct or not in my understanding of your situation, an important message is: you should choose your data structure to facilitate the analysis that you have in mind. IMHO, this is one of R's great strengths: it provides rich facilities for manipulating data tightly integrated with plotting and analytical capabilities. Cheers, Bert On Wed, Nov 2, 2011 at 9:46 AM, Rich Shepard rshep...@appl-ecosys.comwrote: On Wed, 2 Nov 2011, Rich Shepard wrote: I want a subset of this with only 7 chemicals: Ca, Cl, Cond, Mg, Na, SO4, and TDS. I should have also written that what I ultimately want is to create a box-and-whisker plot for these 7 chemicals in a single panel. If that can be done directly from the source data frame without creating another subset, I want to learn the syntax for that. Rich __** R-help@r-project.org mailing list https://stat.ethz.ch/mailman/**listinfo/r-helphttps://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/** posting-guide.html http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Proper Syntax for Logical Subset in Subset()
Of course I left out the data argument: boxplot(Result ~ Chemical, data= yourdat,subset=yourdat$Chemical %in% c(Ca,Cl, Cond,Mg,Na,SO2,TDS)) -- Bert On Wed, Nov 2, 2011 at 10:08 AM, Bert Gunter bgun...@gene.com wrote: To make such a plot, I would have thought your want your data structure to be: yourdat: Column A: Date Column B; Chemical Column C: Result After subsetting this to the chemicals you want or doing the subsetting in your plot command, something like (base R) boxplot(Result ~ Chemical, subset=yourdat$Chemical %in% c(Ca,Cl, Cond,Mg,Na,SO2,TDS)) You probably can get what you want one way or the other with your current data structure -- though you may have to use ggplot or trellis -- but it does appear to be inconvenient. Whether I'm correct or not in my understanding of your situation, an important message is: you should choose your data structure to facilitate the analysis that you have in mind. IMHO, this is one of R's great strengths: it provides rich facilities for manipulating data tightly integrated with plotting and analytical capabilities. Cheers, Bert On Wed, Nov 2, 2011 at 9:46 AM, Rich Shepard rshep...@appl-ecosys.comwrote: On Wed, 2 Nov 2011, Rich Shepard wrote: I want a subset of this with only 7 chemicals: Ca, Cl, Cond, Mg, Na, SO4, and TDS. I should have also written that what I ultimately want is to create a box-and-whisker plot for these 7 chemicals in a single panel. If that can be done directly from the source data frame without creating another subset, I want to learn the syntax for that. Rich __** R-help@r-project.org mailing list https://stat.ethz.ch/mailman/**listinfo/r-helphttps://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/** posting-guide.html http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm [[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.
Re: [R] Proper Syntax for Logical Subset in Subset()
On Wed, 2 Nov 2011, Bert Gunter wrote: To make such a plot, I would have thought your want your data structure to be: Column A: Date Column B; Chemical Column C: Result Thanks, Bert. I have a data frame in that format. After subsetting this to the chemicals you want or doing the subsetting in your plot command, something like (base R) boxplot(Result ~ Chemical, subset=yourdat$Chemical %in% c(Ca,Cl, Cond,Mg,Na,SO2,TDS)) Great! I'll work with this. I tend to use lattice so I can learn its capabilities better. Whether I'm correct or not in my understanding of your situation, an important message is: you should choose your data structure to facilitate the analysis that you have in mind. IMHO, this is one of R's great strengths: it provides rich facilities for manipulating data tightly integrated with plotting and analytical capabilities. I recognize this and continue to learn how best to represent the same data for different analyses and plots. Much appreciated, Rich __ 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.
