SSN2 (version 0.2.1)

ssn_get_netgeom: Extract netgeom column

Description

Extract topological information from netgeom column

Usage

ssn_get_netgeom(x, netvars = "all", reformat = FALSE)

Value

If more than one column is requested using netvars, the function returns a data.frame (default). If only one column is requested, the result is a vector.

Arguments

x

An sf data.frame found in an SSN object or the netgeom column as a vector

netvars

Network coordinate variables to return. Default is "all". For edges, valid column names include: "NetworkID", "SegmentID", and "DistanceUpstream". For point datasets, valid column names include "NetworkID", "SegmentID", "DistanceUpstream", "ratio", "pid", and "locID".

reformat

Convert network coordinate variables from character to numeric.

Details

When an SSN object is generated using the importSSN function, a text column named "netgeom" is added to the edges, observed sites, and prediction sites (if they exist) data.frames. The netgeom column contains data used to describe how edge and site features relate to one another in topological space. For edges, netgeom values contain the "ENETWORK" prefix, with 3 space delimited values in parentheses: "ENETWORK (NetworkID SegmentID DistanceUpstream)". For point datasets (observed and prediction sites), the values contain the "SNETWORK" prefix, followed by 6 space delimited values in parentheses: "SNETWORK (NetworkID SegmentID DistanceUpstream ratio pid locID)". The ssn_get_netgeom function extracts and converts these values from text to numeric, returning either a data.frame (default) or vector containing the variables requested via netvars.

Examples

# Copy the mf04p .ssn data to a local directory and read it into R
# When modeling with your .ssn object, you will load it using the relevant
# path to the .ssn data on your machine
copy_lsn_to_temp()
temp_path <- paste0(tempdir(), "/MiddleFork04.ssn")
mf04p <- ssn_import(temp_path, overwrite = TRUE)

ssn_get_netgeom(mf04p$obs)
ssn_get_netgeom(mf04p$edges, "DistanceUpstream")