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Create Transition Metadata Table

Source: R/trans_meta_t.R
trans_meta_t.Rd

Creates a trans_meta_t table based on observed land use transitions in the LULC data. This function analyzes transition patterns and creates metadata entries for each viable transition type. The metadata is kept constant across runs, since comparisons of model performance should be based on the same set of transitions.

Usage

as_trans_meta_t(x)

create_trans_meta_t(
  transitions,
  min_cardinality_abs = NULL,
  min_frequency_rel = NULL,
  exclude_anterior = NULL,
  exclude_posterior = NULL
)

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

Arguments

transitions

A trans_v table, with columns id_coord, id_lulc_anterior, id_lulc_posterior, id_period; contains transitions and non-transitions (where anterior == posterior)

min_cardinality_abs

Minimum absolute number of transitions for viability (optional)

min_frequency_rel

Minimum relative frequency of transitions for viability (optional)

exclude_anterior

Vector of id_lulc values to exclude as anterior (source) classes

exclude_posterior

Vector of id_lulc values to exclude as posterior (target) classes

nrow

see data.table::print.data.table

...

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

Value

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

  • id_trans: Unique ID for each transition

  • id_lulc_anterior: Foreign key to lulc_meta_t (before transition)

  • id_lulc_posterior: Foreign key to lulc_meta_t (after transition)

  • cardinality: How many times this transition occurred

  • frequency_rel: Frequency relative to all transitions

  • frequency_abs: Frequency relative to all coordinate pairs

  • is_viable: Whether this transition is viable for modelling

Methods (by generic)

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

Functions

  • create_trans_meta_t(): Calculate the transition metadata and mark for modelling feasibility. Does not attribute id_trans; this only makes sense as part of a DB.