Aggregate does the right thing with column names when passing it numerical coordinates. Given a dataframe like this: Nuclei Positive Nuclei Slide 1 133 96 A1 2 96 70 A1 3 62 52 A2 4 60 50 A2 I can call 'aggregate' like this:> aggregate(example[1], by=example[3], sum)Slide Nuclei 1 A1 229 2 A2 122 But that means I have to keep track of which column is which number. If I try it the easy way, it doesn't keep track of column names and it forces me to coerce the 'by' to a list.> aggregate(example$Nuclei, by=list(example$Slide), sum)Group.1 x 1 A1 229 2 A2 122 Is there a better way to do this? Thanks -Ed
On Fri, Jan 22, 2016 at 01:20:59PM -0600, Ed Siefker wrote:> Aggregate does the right thing with column names when passing it > numerical coordinates. > Given a dataframe like this: > > Nuclei Positive Nuclei Slide > 1 133 96 A1 > 2 96 70 A1 > 3 62 52 A2 > 4 60 50 A2 > > I can call 'aggregate' like this: > > > aggregate(example[1], by=example[3], sum) > Slide Nuclei > 1 A1 229 > 2 A2 122 > > But that means I have to keep track of which column is which number. > If I try it the > easy way, it doesn't keep track of column names and it forces me to > coerce the 'by' > to a list. > > > aggregate(example$Nuclei, by=list(example$Slide), sum) > Group.1 x > 1 A1 229 > 2 A2 122 > > Is there a better way to do this? Thanks > -Ed > ....Something like:> aggregate(Nuclei ~ Slide, example, sum)Slide Nuclei 1 A1 229 2 A2 122>perhaps? Peace, david -- David H. Wolfskill r at catwhisker.org Those who would murder in the name of God or prophet are blasphemous cowards. See http://www.catwhisker.org/~david/publickey.gpg for my public key. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 603 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20160122/d78698ac/attachment.bin>
Does this do what you want? aggregate(Nuclei ~ Slide, example, sum) On Fri, Jan 22, 2016 at 12:20 PM, Ed Siefker <ebs15242 at gmail.com> wrote:> Aggregate does the right thing with column names when passing it > numerical coordinates. > Given a dataframe like this: > > Nuclei Positive Nuclei Slide > 1 133 96 A1 > 2 96 70 A1 > 3 62 52 A2 > 4 60 50 A2 > > I can call 'aggregate' like this: > > > aggregate(example[1], by=example[3], sum) > Slide Nuclei > 1 A1 229 > 2 A2 122 > > But that means I have to keep track of which column is which number. > If I try it the > easy way, it doesn't keep track of column names and it forces me to > coerce the 'by' > to a list. > > > aggregate(example$Nuclei, by=list(example$Slide), sum) > Group.1 x > 1 A1 229 > 2 A2 122 > > Is there a better way to do this? Thanks > -Ed > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. >-- Cooperative Fish and Wildlife Research Unit Zoology and Physiology Dept. University of Wyoming JoeCeradini at gmail.com / 914.707.8506 wyocoopunit.org [[alternative HTML version deleted]]
So that's how that works! Thanks. On Fri, Jan 22, 2016 at 1:32 PM, Joe Ceradini <joeceradini at gmail.com> wrote:> Does this do what you want? > > aggregate(Nuclei ~ Slide, example, sum) > > On Fri, Jan 22, 2016 at 12:20 PM, Ed Siefker <ebs15242 at gmail.com> wrote: >> >> Aggregate does the right thing with column names when passing it >> numerical coordinates. >> Given a dataframe like this: >> >> Nuclei Positive Nuclei Slide >> 1 133 96 A1 >> 2 96 70 A1 >> 3 62 52 A2 >> 4 60 50 A2 >> >> I can call 'aggregate' like this: >> >> > aggregate(example[1], by=example[3], sum) >> Slide Nuclei >> 1 A1 229 >> 2 A2 122 >> >> But that means I have to keep track of which column is which number. >> If I try it the >> easy way, it doesn't keep track of column names and it forces me to >> coerce the 'by' >> to a list. >> >> > aggregate(example$Nuclei, by=list(example$Slide), sum) >> Group.1 x >> 1 A1 229 >> 2 A2 122 >> >> Is there a better way to do this? Thanks >> -Ed >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. > > > > > -- > Cooperative Fish and Wildlife Research Unit > Zoology and Physiology Dept. > University of Wyoming > JoeCeradini at gmail.com / 914.707.8506 > wyocoopunit.org >
Using column names where you used column numbers would work:
example <- data.frame(
check.names = FALSE,
Nuclei = c(133L, 96L, 62L, 60L),
`Positive Nuclei` = c(96L, 70L, 52L, 50L),
Slide = factor(c("A1", "A1", "A2",
"A2"), levels = c("A1", "A2")))
aggregate(example["Nuclei"], by=example["Slide"], sum)
# Slide Nuclei
#1 A1 229
#2 A2 122
aggregate(example[1], by=example[3], sum)
# Slide Nuclei
#1 A1 229
#2 A2 122
Many people find that the functions in the dplyr or plyr packages
are worth the trouble to learn about.
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Fri, Jan 22, 2016 at 11:20 AM, Ed Siefker <ebs15242 at gmail.com>
wrote:
> Aggregate does the right thing with column names when passing it
> numerical coordinates.
> Given a dataframe like this:
>
> Nuclei Positive Nuclei Slide
> 1 133 96 A1
> 2 96 70 A1
> 3 62 52 A2
> 4 60 50 A2
>
> I can call 'aggregate' like this:
>
> > aggregate(example[1], by=example[3], sum)
> Slide Nuclei
> 1 A1 229
> 2 A2 122
>
> But that means I have to keep track of which column is which number.
> If I try it the
> easy way, it doesn't keep track of column names and it forces me to
> coerce the 'by'
> to a list.
>
> > aggregate(example$Nuclei, by=list(example$Slide), sum)
> Group.1 x
> 1 A1 229
> 2 A2 122
>
> Is there a better way to do this? Thanks
> -Ed
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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]]