xs_cumulative_change: Cross Section Cumulative Change
In mkoohafkan/RAStestR: Functions for testing RAS outputs

Description Usage Arguments Details Examples

Compute cumulative cross section change directy from cross section data.

xs_cumulative_change(d, time.col = "Time", station.col = "Station",
  distance.col = "Distance", elevation.col = "Elevation",
  bank.stations = NULL, reference.elevation = NULL,
  bottom.elevation = NULL, station.lengths = NULL, over.time = TRUE,
  longitudinal = TRUE, direction = "downstream")

`d`	The cross section data, i.e. output of `read_xs`.
`time.col`	The column containing time stamps.
`station.col`	The column containing cross section station IDs.
`distance.col`	The column containing cross section distances.
`elevation.col`	The column containing cross section elevations.
`bank.stations`	A table defining the bank station distances to use when computing cross section area. If `NULL`, the full extent of each cross section will be used. See details for more information.
`reference.elevation`	Use predefined reference elevations when computing cross section area. Can be a constant or a two column station of cross section labels and associated reference elevation. If `NULL`, the maximum elevation of each cross section will be used.
`bottom.elevation`	Use predefined bottom elevations when computing cross section area. Can be a constant or a two column station of cross section labels and associated bottom elevation. If `NULL`, the minimum elevation of each cross section will be used.
`station.lengths`	The cross section length values.
`over.time`	If `TRUE`, accumulate data across time steps. This is generally valid only for data output at the computation time step.
`longitudinal`	If `TRUE`, accumulate data along the reach. This is generally only valid when all cross sections are included in `d`.
`direction`	Accumulate data in the downstream (descending order of cross section IDs) or upstream (ascending order) direction. Ignored if `longitudinal` is `FALSE`.

This is essentially a wrapper for processing cross section data through the sequence xs_area –> area_to_volume –> change_table –> cumulative_table.

simple.quasi = system.file("sample-data/SampleQuasiUnsteady.hdf",
  package = "RAStestR")

quasi.xs = read_xs(simple.quasi)
quasi.lengths = xs_lengths(read_station_lengths(simple.quasi))
xs_cumulative_change(quasi.xs, station.lengths = quasi.lengths)
xs_cumulative_change(quasi.xs, station.lengths = quasi.lengths,
  longitudinal = FALSE)
xs_cumulative_change(quasi.xs, station.lengths = quasi.lengths,
  over.time = FALSE, direction = "upstream")

quasi.banks = read_bank_stations(simple.quasi)
xs_cumulative_change(quasi.xs, station.lengths = quasi.lengths,
  bank.stations = quasi.banks, reference.elevation = 1200)