R help - May 2011 - Summarize by two or more attributes

Okay everyone heres a likely softball for someone.

Consider the following data frame:

#Create data
x<-rep(c(1,15),10)
y<-rnorm(20)
z<-c(rep("auto",10),rep("bus",10))
a<-rep(c(1,1,2,2,3,3,4,4,5,5),2)
#Create Data frame
Df<-data.frame(Source=x,Rate=y,Bin=a,Type=z)


I want to create a new column the equals the sum of the Rates for each type
(1,15) by Bin.  

A related question:  I have been using R for a while now and usually
manipulate my data in data frames but i know lists are better for R so
perhaps the above should be done using lists.  Feel free to offer
suggestions coming from that angle.  

Thanks guys

JR-



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I will hit my own ball on this one


tapply(Df$Rate,list(Df$Bin,Df$Type),sum)

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One possibility is:

library(doBy)
summaryBy(Rate~Source+Bin, data=Df, FUN=sum)


On 5/17/2011 12:48 PM, LCOG1 wrote:
> Okay everyone heres a likely softball for someone.
>
> Consider the following data frame:
>
> #Create data
> x<-rep(c(1,15),10)
> y<-rnorm(20)
> z<-c(rep("auto",10),rep("bus",10))
> a<-rep(c(1,1,2,2,3,3,4,4,5,5),2)
> #Create Data frame
> Df<-data.frame(Source=x,Rate=y,Bin=a,Type=z)
>
>
> I want to create a new column the equals the sum of the Rates for each type
> (1,15) by Bin.
>
> A related question:  I have been using R for a while now and usually
> manipulate my data in data frames but i know lists are better for R so
> perhaps the above should be done using lists.  Feel free to offer
> suggestions coming from that angle.
>
> Thanks guys
>
> JR-
>
>
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/Summarize-by-two-or-more-attributes-tp3529825p3529825.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
	[[alternative HTML version deleted]]

Like This?

x<-rep(c(1,15),10)
y<-rnorm(20)
z<-c(rep("auto",10),rep("bus",10))
a<-rep(c(1,1,2,2,3,3,4,4,5,5),2)
#Create Data frame
Df<-data.frame(Source=x,Rate=y,Bin=a,Type=z)
Df

ddply(Df,c('Type','Bin'),summarise,Summed=sum(Rate))

?# Adding a column to Df
ddply(Df,c('Type','Bin'),mutate,Summed=sum(Rate))
? 
# Convert the result to a list
dlply(Df,c('Type','Bin'),summarise,Summed=sum(Rate))


?
Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA
http://www.fws.gov/redbluff/rbdd_jsmp.aspx




----- Original Message ----
> From: LCOG1 <jroll at lcog.org>
> To: r-help at r-project.org
> Sent: Tue, May 17, 2011 9:48:36 AM
> Subject: [R] Summarize by two or more attributes
> 
> Okay everyone heres a likely softball for someone.
> 
> Consider the following data frame:
> 
> #Create data
> x<-rep(c(1,15),10)
> y<-rnorm(20)
> z<-c(rep("auto",10),rep("bus",10))
> a<-rep(c(1,1,2,2,3,3,4,4,5,5),2)
> #Create Data frame
> Df<-data.frame(Source=x,Rate=y,Bin=a,Type=z)
> 
> 
> I want to create a new column the equals the sum of the Rates for each type
> (1,15) by Bin.? 
> 
> A related question:? I have been using R for a while now and usually
> manipulate my data in data frames but i know lists are better for R so
> perhaps the above should be done using lists.? Feel free to offer
> suggestions coming from that angle.? 
> 
> Thanks guys
> 
> JR-
> 
> 
> 
> --
> View this message in context: 
>http://r.789695.n4.nabble.com/Summarize-by-two-or-more-attributes-tp3529825p3529825.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.
>

On May 17, 2011, at 11:48 AM, LCOG1 wrote:
> Okay everyone heres a likely softball for someone.
> 
> Consider the following data frame:
> 
> #Create data
> x<-rep(c(1,15),10)
> y<-rnorm(20)
> z<-c(rep("auto",10),rep("bus",10))
> a<-rep(c(1,1,2,2,3,3,4,4,5,5),2)
> #Create Data frame
> Df<-data.frame(Source=x,Rate=y,Bin=a,Type=z)
> 
> 
> I want to create a new column the equals the sum of the Rates for each type
> (1,15) by Bin.  
> 
> A related question:  I have been using R for a while now and usually
> manipulate my data in data frames but i know lists are better for R so
> perhaps the above should be done using lists.  Feel free to offer
> suggestions coming from that angle.  
> 
> Thanks guys
> 
> JR-

See ?ave and consider:

# Presuming you want 'Bin' nested within 'Source'
Df$Sum <- ave(Df$Rate, list(Df$Source, Df$Bin), FUN = sum)

# Or 'Source' nested within 'Bin'
Df$Sum <- ave(Df$Rate, list(Df$Bin, Df$Source), FUN = sum)


On your follow up, a data frame is a type of list with a 'data.frame'
class attribute, a 'row.names' attribute and a 'names' attribute
for the column names. Much like a matrix is a vector with a 'dim'
attribute.

Try this:

  unclass(Df)

and see the output. It looks just like a list, because it is...

If dealing with 'rectangular' datasets (eg. a database table), where
each column may need to be of differing data types, a data frame in R is
specifically designed to handle it. It is because a data frame is a list, that
it can do this, since each element in a list can be a different type.

If you need to deal with a data structure that may not be entirely based upon a
rectangular data set and may need to contain various numbers of items per
element, then a list is the way to go. Lists are commonly used in R functions to
return complex objects that may contain vectors of various types, matrices, data
frames and even lists of lists.

A quick example would be objects returned by R's model functions. Run
example(lm) and after the graphs finish, use str(lm.D9) to give an example of
the structure of a somewhat complex list object.

HTH,

Marc Schwartz