count
Construct, coerce, and test for a count object
In package untb, ecosystem data is held in one of two preferred forms:
census data and count data. Function count creates an object
of class “count”, and as.count() coerces to this class.
- Keywords
- math
Usage
as.count(a,add="")
count(a)
is.count(a)Arguments
- a
- Ecosystem data. In function
as.count(), if a table, interpret as species count data; otherwise, interpret as census data. Special dispensation is made for single rows of a dataframe - add
- In function
as.count(), character argument with default""(empty string) meaning to leave the species names unchanged. A non-empty string is prepended to the species names usingpaste(). This is useful if the species names are integers because the display can become confusing
Details
A “count” object is a list of species together with their abundance. It also has class “table”; compare “census” objects. An object of class “count” is a table sorted from most to least abundant species. The singletons are thus tabulated last.
Function count() takes a vector, the elements of which are
interpreted as abundances. If any of the elements are named, the
names are interpreted as species names (unnamed elements are given the
null name). If the vector is unnamed, then the species names are
upper case letters, with the first element being named
“A”, the second “B”, and so on; this
behaviour is inherited from as.table(). Note that this means
that the species names are not necessarily in alphabetical order.
From version 1.6-9, zero elements are interpreted as zero abundance
species (ie extinct).
To access or change species names, use names() and
names<- respectively.
Function as.count() coerces its argument to count form.
Value
-
Returns an object of class “count”.
See Also
Examples
a <- c(rep("oak",5) ,rep("ash",2),rep("elm",3),rep("xx",4))
as.count(a)
data(saunders)
as.count(saunders[1,-(1:150)])
jj <- sample(1:5,5,replace=TRUE)
as.count(jj)
as.count(jj,add="spp.")