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Split effort by strata

Source: R/das_effort_strata.R
das_effort_strata.Rd

Split DAS effort where it intersects with a stratum boundary

Usage

das_effort_strata(x, ...)

# S3 method for class 'data.frame'
das_effort_strata(x, ...)

# S3 method for class 'das_df'
das_effort_strata(x, strata.files, ...)

Arguments

x

an object of class das_df, or a data frame that can be coerced to class das_df

...

ignored

strata.files

list of path(s) of the stratum CSV file(s); see das_effort()

Value

The data frame x, with 1) columns added that indicate a) if the point was in a particular stratum (see das_intersects_strata()), and b) the index of the stratum in strata.files (column name 'stratum'; 0 if the point intersects with no strata), and 2) two rows added for each strata crossing that occurs between something other than an E and R. These rows are necessary because of how das_effort processes effort. The added rows are the same as the event previous to the strata crossing, except:

  • They have the event code "strataE" and "strataR", respectively

  • Their coordinates are the coordinates of the intersection of the effort line and the stratum boundary

  • Their 'idx_eff' values are plus 0.4 and 0.5, respectively

  • The second added row has the same stratum info as the point immediately after the stratum boundary crossing

Details

This function should only be called by das_effort(), i.e. it should not be called by users in their personal scripts. Practically speaking, this functions splits the effort line wherever it crosses a stratum line. This point of intersection is interpolated; specifically, it is determined using sf::st_intersection(). Thus, any effort will be first split at these effort-stratum boundary intersection points, and then using the specified method (e.g. condition).