[R] Getting group size in a data frame

2006-10-19 Thread Ulrik Stervbo 
Hi all,

I have a data frame with some measured values of some animals. Sometimes the
measurement failed, resulting in a NA for a measurement and sometimes the
animal died, resulting in NA for all measurements.

I have several groups of animals. How do I find the size of each group with
only alive animals? And how do I find the size of the groups for each
measurement?

An example:
l1 - list(factor=c(24,24,24), val1=c(2, 3, NA), val2=c(4, NA, NA))
df - as.data.frame(l1)
df$factor - factor(df$factor)

The size of factors should be 2 and not 3.  The number of measurement in
val1 should be 2 and the number of measurements in val2 should be 1

Thanks in advance for any help and suggestions
Ulrik

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Re: [R] Getting group size in a data frame

2006-10-19 Thread Alex Brown 

I can't quite tell what you are looking for, but try the following:

measurecols = c(val1,val2)
df2 - df[!apply(is.na(df[1:nrow(df),measuredcols]),1,all),]

to remove rows which have no measurements in.

a simple count of the rows (nrow) will then give you the number of  
animals that didn't die, and then

table(df2$factor)

will tell you how many per group didn't die

table(df2$factor[!is.na(df2$val1)]

and

names(measurecols) = measurecols

lapply(measurecols, function(x)table(df2$factor[!is.na(df2[,x])]))

will tell you for each measurement, how many of each group you got.

-Alex

On 19 Oct 2006, at 08:37, Ulrik Stervbo wrote:

 Hi all,

 I have a data frame with some measured values of some animals.  
 Sometimes the
 measurement failed, resulting in a NA for a measurement and  
 sometimes the
 animal died, resulting in NA for all measurements.

 I have several groups of animals. How do I find the size of each  
 group with
 only alive animals? And how do I find the size of the groups for each
 measurement?

 An example:
 l1 - list(factor=c(24,24,24), val1=c(2, 3, NA), val2=c(4, NA, NA))
 df - as.data.frame(l1)
 df$factor - factor(df$factor)

 The size of factors should be 2 and not 3.  The number of  
 measurement in
 val1 should be 2 and the number of measurements in val2 should be 1

 Thanks in advance for any help and suggestions
 Ulrik

   [[alternative HTML version deleted]]

 __
 R-help@stat.math.ethz.ch 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.

__
R-help@stat.math.ethz.ch 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] Getting group size in a data frame [Broadcast]

2006-10-19 Thread Liaw, Andy 
Is this sort of what you want?

R aggregate(df[2:3], df[1], function(x) sum(!is.na(x)))
  factor val1 val2
1 2421

Andy 

From: Ulrik Stervbo
 
 Hi all,
 
 I have a data frame with some measured values of some 
 animals. Sometimes the
 measurement failed, resulting in a NA for a measurement and 
 sometimes the
 animal died, resulting in NA for all measurements.
 
 I have several groups of animals. How do I find the size of 
 each group with
 only alive animals? And how do I find the size of the groups for each
 measurement?
 
 An example:
 l1 - list(factor=c(24,24,24), val1=c(2, 3, NA), val2=c(4, NA, NA))
 df - as.data.frame(l1)
 df$factor - factor(df$factor)
 
 The size of factors should be 2 and not 3.  The number of 
 measurement in
 val1 should be 2 and the number of measurements in val2 should be 1
 
 Thanks in advance for any help and suggestions
 Ulrik
 
   [[alternative HTML version deleted]]
 
 __
 R-help@stat.math.ethz.ch 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.
 
 
 


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