step_earthtide: Earth tide response
In hydrorecipes: Hydrogeology Steps for the 'recipes' Package

View source: R/step_earthtide.R

step_earthtide

R Documentation

Earth tide response

Description

step_earthtide creates a specification of a recipe step that are the Earth tide harmonics for a particular location. This step requires the earthtide package.

Usage

step_earthtide(
  recipe,
  ...,
  role = "predictor",
  trained = FALSE,
  do_predict = FALSE,
  method = "gravity",
  astro_update = 1L,
  latitude = 0,
  longitude = 0,
  elevation = 0,
  azimuth = 0,
  gravity = 0,
  earth_radius = 6378136.3,
  earth_eccen = 0.0066943979514,
  cutoff = 1e-06,
  wave_groups = NULL,
  catalog = "ksm04",
  eop = NULL,
  scale = TRUE,
  prefix = "earthtide_",
  columns = NULL,
  keep_original_cols = FALSE,
  skip = FALSE,
  id = rand_id("earthtide")
)

Arguments

`recipe`	A recipe object. The step will be added to the sequence of operations for this recipe.
`...`	One or more selector functions to choose which variables are affected by the step. See `selections()` for more details. For the `tidy` method, these are not currently used.
`role`	Defaults to "earthtide"
`trained`	A logical to indicate if the quantities for preprocessing have been estimated.
`do_predict`	run in predict or analyze mode
`method`	One or more of "gravity", "tidal_potential", "tidal_tilt", "vertical_displacement", "horizontal_displacement", "n_s_displacement", "e_w_displacement", "vertical_strain", "areal_strain", "volume_strain", "horizontal_strain", or "ocean_tides", "pole_tide", "lod_tide". The pole tide and lod_tide are used in predict mode even if do_predict is FALSE. More than one value can only be used if do_predict == TRUE.
`astro_update`	Integer that determines how often to phases are updated in number of samples. Defaults to 1 (every sample), but speed gains are realized with larger values. Typically updating every hour will have speed gains and keep precision (ie 3600 for one second data, 60 for minute data, 1 for hourly data).
`latitude`	The station latitude (numeric) defaults to 0.
`longitude`	The station longitude (numeric) defaults to 0.
`elevation`	The station elevation (m) (numeric) defaults to 0.
`azimuth`	Earth azimuth (numeric) defaults to 0.
`gravity`	Gravity at the station (m/s^2) (numeric) 0 to estimate gravity from elevation and latitude.
`earth_radius`	Radius of earth (m) (numeric) defaults to 6378136.3
`earth_eccen`	Eccentricity of earth (numeric) defaults to 6.69439795140e-3
`cutoff`	Cutoff amplitude for constituents (numeric) defaults to 1e-6.
`wave_groups`	Two column data.frame having start and end of frequency groups (data.frame). This data.frame must have two columns with the names 'start', and 'end' signifying the start and end of the wave groupings. An optional third column 'multiplier' can be provided to scale the particular wave group. If column names do no match, the inferred column positions are start, end, multiplier.
`catalog`	Use the "hw95s" catalog or "ksm04" catalog (character).
`eop`	User defined Earth Orientation Parameter (EOP) data.frame with the following columns: datetime, ddt, ut1_utc, lod, x, y, dx, dy
`scale`	Scale results when do_predict is FALSE
`prefix`	A prefix for generated column names, default to "earthtide_".
`columns`	A character string of variable names that will be populated (eventually) by the `terms` argument.
`keep_original_cols`	A logical to keep the original variables in the output. Defaults to `FALSE`.
`skip`	A logical. Should the step be skipped when the recipe is baked by `bake()`? While all operations are baked when `prep()` is run, some operations may not be able to be conducted on new data (e.g. processing the outcome variable(s)). Care should be taken when using `skip = TRUE` as it may affect the computations for subsequent operations.
`id`	A character string that is unique to this step to identify it.

Details

There are many waves (thousands) that make up a tidal signal. step_earthtide calculates the Earth tide signal for a time and location. The tidal signal can be estimated as a single summed curve when do_predict = TRUE or as a set of wave groups when do_predict = FALSE. Wave groups are ranges of frequencies identified by start and end frequencies. For example, if you have one month of data the M2 signal could be described as the sum of all the waves between 1.914129 and 1.950419 cycles per day. The regressors for each wave group have a sin and cos component. See recipes::step_harmonic() for a simplified version of this where each sin and cos curve corresponds to a single wave.

Value

An updated version of recipe with the new step added to the sequence of existing steps (if any).

Examples

library(earthtide)
data(eterna_wavegroups)
data(transducer)

transducer <- transducer[, c('datetime', 'wl'),]
t_sub <- transducer[(as.numeric(transducer$datetime) %% 14400) == 0, ]
wg <- na.omit(eterna_wavegroups[eterna_wavegroups$time == '1 month',])

recipe(wl ~ ., data = t_sub) |>
  step_earthtide(datetime,
                 latitude = 34,
                 longitude = -118.5,
                 wave_groups = wg,
                 do_predict = FALSE) |>
  prep()

recipe(wl ~ ., data = t_sub) |>
  step_earthtide(datetime,
                 latitude = 34,
                 longitude = -118.5,
                 wave_groups = wg,
                 do_predict = TRUE) |>
  prep()

hydrorecipes documentation built on June 27, 2022, 9:06 a.m.