Description Usage Arguments Details Value Author(s) Examples
The function allows for an easy transformation of Braun-Blanquet (or any other phytosciological scale) data to numeric values for numerical analysis or vice versa. Be aware that this transformation is not losless regarding the information content.
1 2 |
dat |
A species matrix. |
from |
Definition of the imput scale. Per default the transformation is done from the classic Braun-Blanquet scale to cover percentages. For transformation from numerical values to a phytosociological scale see details and example. |
to |
Definition of the output scale. The default are the recommended class centers when transforming BB to percentage cover values. Can be changed according to your needs. See details. |
When transforming from a phytosociological scale to Braun-Blanquetfrom
and to
have to be the same length. In case of transformation from numerical cover values to a phytosociological scale the function expects a numerical vector in from
that, for each class, gives the lower and upper limit. Thus, length(from) == 2*length(to)
in this case.
Returns a species matrix in the specified format.
Gerald Jurasinski gerald.jurasinski@uni-rostock.de
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | ## Create a species that occurs on 7 plots
## with all the different possibilities of
## the BB scale
spec <- c("r", "+", "0", "1", "2", "3", "4", "5")
## Create a highly artificial species matrix.
## All species are the same for simplicity
dat.bb <- data.frame(spec, spec, spec, spec, spec, spec)
## Transform from BB scale to percentage values
dat.proc <- bb2num(dat.bb)
## When transforming back the class definitions are a little
## more complicated. Just give the lower and upper limits for
## each class in the from vector class for class.
from <- c(0, 0.1, 0.1, 2, 2, 5, 5, 25, 25, 50, 50, 75, 75, 100)
to <- c("r", "+", "1", "2", "3", "4", "5")
bb2num(dat.proc, from=from, to=to)
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