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Create Transition Rates Table

Source: R/trans_rates_t.R
trans_rates_t.Rd

Creates a trans_rates_t table that stores transition rates (probabilities) for each transition type in each time period. Historical rates are calculated from observed transitions, and future rates are extrapolated using linear regression.

Usage

as_trans_rates_t(x)

get_obs_trans_rates(self)

extrapolate_trans_rates(obs_rates, periods, coord_count = NA_integer_)

# S3 method for class 'trans_rates_t'
print(x, nrow = 10, ...)

Arguments

x

A list or data.frame coercible to a data.table

self

a DB instance

obs_rates

A trans_rates_t table of observed transition rates for historical periods

periods

A periods_t table with is_extrapolated = TRUE for future periods

coord_count

Optional integer specifying the number of coordinates (cells) for normalization

nrow

see data.table::print.data.table

...

passed to data.table::print.data.table

Value

A data.table of class "trans_rates_t" with columns:

  • id_run: Foreign key to runs_t

  • id_period: Foreign key to periods_t

  • id_trans: Foreign key to trans_meta_t

  • count: Absolute count of transitions

  • rate: Transition rate: count of transitions in (id_trans, id_period) over (id_period)

Methods (by generic)

  • print(trans_rates_t): Print a trans_rates_t object, passing params to data.table print

Functions

  • get_obs_trans_rates(): Calculate observed transition rates from historical data. For each period and transition type, calculates the rate as the proportion of id_lulc_anterior cells that transitioned to id_lulc_posterior.

  • extrapolate_trans_rates(): Return future transition rates using linear regression. For each id_run + id_trans, fits a linear model of rate vs period number and extrapolates to future periods. Negative predicted rates are set to 0.