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.
as.count(a,add="") count(a) is.count(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
- 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 using
paste(). This is useful if the species names are integers because the display can become confusing
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.
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
as.count() coerces its argument to count form.
Returns an object of class count.
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.")