as.mefa {mefa} | R Documentation |
Conversion Among Various Object Classes
Description
These functions coerce into class 'mefa' or 'stcs'; or converts 'mefa' or 'stcs' obects into a 'data.frame', 'matrix', 'array', 'list'.
Usage
as.stcs(x, ...)
## Default S3 method:
as.stcs(x, ...)
as.mefa(x, ...)
as.Mefa(x, ...)
as.Xtab(x, ...)
## Default S3 method:
as.mefa(x, samp, taxa, ...)
## S3 method for class 'array'
as.mefa(x, ...)
## S3 method for class 'list'
as.mefa(x, ...)
## S3 method for class 'mefa'
as.matrix(x, ...)
## S3 method for class 'mefa'
as.array(x, ...)
## S3 method for class 'mefa'
as.list(x, ...)
## S3 method for class 'stcs'
as.data.frame(x, ...)
## S3 method for class 'mefa'
as.data.frame(x, ..., fun, name, make.unique = FALSE)
mss(x, name, make.unique = FALSE, ...)
msr(x, name, make.unique = FALSE, ...)
mts(x, name, make.unique = FALSE, ...)
mtr(x, name, make.unique = FALSE, ...)
Arguments
x |
an object of class 'mefa'. |
samp |
a data frame containing rows for samples, or |
taxa |
a data frame containing rows for taxa, or |
fun |
a function to determine what to return, see details. It has no default, because the choice is not trivial. |
name |
optional character vector, names to return if not all possible elements are needed, see details. |
make.unique |
logical, useful to use |
... |
other arguments passed to the generic function |
Details
The usage of most of these coercion methods is trivial. Arrays and lists can be coerced into 'mefa' objects as if those were the segm
element of it (either nested, or non nested). The reverse is true, when coercing an object of class 'mefa' into list or array, the segm
element is used.
Coercing among object classes 'matrix' and 'mefa' is done via using the xtab
element.
By as.data.frame.mefa
, four kinds of data frames can be returned, depending on the function used as the fun
argument:
mss
returns summary statistics for samples (richness and abundance) and x$samp
;
msr
returns raw data (x$xtab
) and x$samp
;
mts
returns summary statistics for taxa (occurrence and abundance) and x$taxa
;
mtr
returns raw data (t(x$xtab)
) and x$taxa
.
The name
can be used if only a subset of the summary statistics, or raw data should be returned. The character vector should contain names of elements to return (see examples).
It might (rarely) occur, that names of the summary statistics, or the raw data and the column names of the sample/taxa table overlap (contains names that are common in the two set). In this case, the make.unique = TRUE
can be used to resolve non-uniqueness and avoid the error message produced otherwise.
The functions supplied as the fun
argument can be used separately. Although the usage of the as.data.frame
method is more transparent.
Value
An object of class 'stcs', 'mefa', 'matrix', 'array', 'list' or 'data.frame', depending on the method used.
Author(s)
P\'eter S\'olymos, solymos@ualberta.ca
References
S\'olymos P. (2008) mefa: an R package for handling and reporting count data. Community Ecology 9, 125–127.
S\'olymos P. (2009) Processing ecological data in R with the mefa package. Journal of Statistical Software 29(8), 1–28. doi:10.18637/jss.v029.i08
http://mefa.r-forge.r-project.org/
See Also
mefa
, stcs
, as.matrix
, as.list
, as.array
, as.data.frame
Examples
data(dol.count, dol.samp, dol.taxa)
x <- mefa(stcs(dol.count), dol.samp, dol.taxa)
## These two are equivalent
as.data.frame(x, fun = mss)
mss(x)
## Return only two species
as.data.frame(x, fun = msr, c("iiso", "ppyg"))
## Taxa table and summary
as.data.frame(x, fun = mts)
## Taxa table and raw data transpose
as.data.frame(x, fun = mtr)
## Why is it useful?
## Instead of
glm(x$xtab[,"amin"] ~ microhab + method, data = x$samp, family = poisson)
## it is more convenient to use
glm(amin ~ microhab + method, data = msr(x), family = poisson)