Convert values of a categorical cover scale to percentage values.
This function requires as input a coverconvert object which contains the conversion tables.
In the case of vegtable objects, the conversion is already embedded
in the slot coverconvert.
Three rules are implemented for transformation, either top (values
transformed to the top of the range), middle (transformation at the
midpoint), and bottom (conversion at the lowest value of the
range). In the later case, transformation ranges starting at 0% of cover
can be set to a different value by the argument zeroto.
When replace=FALSE, existing values of cover in the vegtable
object will be maintained. Since there is not a standard naming of cover
values, in the transformation the name of cover variable should be
indicated in the argument to.
Arguments
- ...
Further arguments passed from or to other methods.
- _data, x
Either a factor or character vector, or a vegtable object.
- conversion
An object of class vegtable.
- from
Scale name of values in
xas character value.- to
Name of the column in slot
samplesfor writing converted values.- replace
Logical value indicating whether existing cover values should be replaced or not.
- rule
Rule applied for the conversion (see details).
- zeroto
Value used to replace levels with bottom at 0% cover.
Value
Either a vector or a vegtable object.
Author
Miguel Alvarez kamapu78@gmail.com