subsetHz,SoilProfileCollection-method: Subset the horizons in a SoilProfileCollection using logical criteria
Description
subsetHz() is a function used for extracting horizons from a SoilProfileCollection based on logical criteria.
Usage
# S4 method for SoilProfileCollection
subsetHz(x, ..., drop = TRUE)
Value
a SoilProfileCollection with a subset of horizons, possibly with some sites removed
Arguments
x
a SoilProfileCollection
...
Comma-separated set of R expressions that evaluate as TRUE or FALSE in context of horizon data frame. Length for individual expressions matches number of horizons, in x.
drop
Default: TRUE. When drop=FALSE placeholder horizons (profile ID with all other values NA) are created where the specified filter results in removal of all horizons.
Details
To minimize likelihood of issues with non-standard evaluation context, especially when using subsetHz() inside another function, all expressions used in ... should be in terms of variables that are in the horizon data frame.