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Last data update: 2014.03.03

R: Tabulates vegetation tables from Turboveg database

tv.veg

R Documentation

Tabulates vegetation tables from Turboveg database

Description

Tabulates vegetation tables from Turboveg resp. VegetWeb database, including taxonomic emendation and layer combination. Using various default parameters for the included functions. It is a wrapper for tv.obs, taxval, tv.coverperc.

Usage

tv.veg(db, taxval=TRUE,tv_home,convcode=TRUE,lc = c("layer","mean","max","sum","first"), 
pseudo, values='COVER_PERC', spcnames=c('short','long','numbers'), dec = 0, 
cover.transform = c('no', 'pa', 'sqrt'), obs, refl, RelScale, ...)

Arguments

`db`	Name of your Turboveg database. Directory name containing tvabund.dbf, tvhabita.dbf and tvwin.set. Please specify pathnames below (if you sorted your databases in subfolders) but not above Turbowin/Data.
`tv_home`	Turbowin installation path.
`taxval`	Should taxonomic valuation (see `taxval`) be performed?
`convcode`	Should cover code be converted to percentage values?
`lc`	Layer combination type. Possible values: layer (default), sum, mean or max, see details
`pseudo`	List used for layer combinations, see details
`values`	Name of the variable which should be used for the vegetations matrix.
`spcnames`	Should species numbers be replaced by shortletters or real names?
`dec`	Number of decimals for cover values in the resulting vegetation matrix.
`cover.transform`	If you want to transform the abundancce values within your samples you can choose 'pa' for presence-absnece or 'squareroot' for the `dec` rounded square root.
`obs`	Observations, optional
`refl`	Taxonomic reference list, optional
`RelScale`	Vector with Cover Scale code per Releve.
`...`	additional arguments for included functions

Details

layer means, the different layers are combined assuming there independence (a species occuring in two layers with a cover of 50% will result in a overall cover of 75%. sum will sum up cover values of all layers

With option pseudo you can decide, which layers should be combined. Give a list with a combination data.frame (see lc and second the name of the column for combination. The default is pseudo = list(lc.1, c('LAYER')), where lc.1 is a data.frame data(lc.1), which will combine all tree layers, all shrub layers and all layers below shrubs. An alternative would be data(lc.all), combining all layers. With option pseudo=NULL there will be no layer aggregation.

Value

Function returns an object of class matrix with (combined) cover values.

Author(s)

Florian Jansen jansen@uni-greifswald.de

Examples

## Not run: 
vignette("vegdata")
# If you have Turboveg installed on your computer try for a beginning 
# tv.veg('databasename', tax=FALSE).
args(tv.veg)
help('taxval')

veg <- tv.veg('taxatest')
names(veg)
tv.veg('taxatest', uncertain=list('DET_CERT', data.frame(0:2,c('pres','agg','agg'))), 
pseudo=list(lc.0,'LAYER'), genus = 'delete')

## End(Not run)