GCubeR (version 0.1.3)

dagnelie_vc22_2: Two-entry Dagnelie volume (tarif 2)

Description

Computes the standing volume \(v_{c,22}\) (in cubic metres) using Dagnelie's two-entry tarif 2 equations. The volume is calculated from the stem circumference at 1.30 m (c130, in cm), the total height of the tree (htot, in m), and the tree species, using species-specific polynomial coefficients stored in dan2.

Usage

dagnelie_vc22_2(data, output = NULL)

Value

A data.frame identical to data but augmented with:

• the joined columns from dan2 (coeff_a, coeff_b, coeff_c, coeff_d, coeff_e, coeff_f, min_c130, max_c130, min_htot, max_htot),

• tarif2: the Dagnelie two-entry volume \(v_{c,22}\) in m\(^3\) per tree.

Arguments

data

A data.frame containing at least the columns c130 (stem circumference at 1.30 m, in cm), htot (height of the tree, in m), and species_code (character code of the tree species).

output

Optional file path where the resulting data frame should be exported as a CSV. If NULL (default), no file is written. Export is handled by the utility function export_output() and failures trigger warnings without interrupting execution.

Supported species

The following species codes are currently supported by dagnelie_vc22_2:

• "QUERCUS_SP"

• "QUERCUS_ROBUR"

• "QUERCUS_PETRAEA"

• "QUERCUS_PUBESCENS"

• "QUERCUS_RUBRA"

• "FAGUS_SYLVATICA"

• "ACER_PSEUDOPLATANUS"

• "FRAXINUS_EXCELSIOR"

• "ULMUS_SP"

• "PRUNUS_AVIUM"

• "BETULA_SP"

• "ALNUS_GLUTINOSA"

• "PICEA_ABIES"

• "PSEUDOTSUGA_MENZIESII"

• "LARIX_SP"

• "PINUS_SYLVESTRIS"

• "CRATAEGUS_SP"

• "PRUNUS_SP"

• "CARPINUS_SP"

• "CASTANEA_SATIVA"

• "CORYLUS_AVELLANA"

• "MALUS_SP"

• "PYRUS_SP"

• "SORBUS_ARIA"

• "SAMBUCUS_SP"

• "RHAMNUS_FRANGULA"

• "PRUNUS_CERASUS"

• "ALNUS_INCANA"

• "POPULUSxCANADENSIS"

• "POPULUS_TREMULA"

• "PINUS_NIGRA"

• "PINUS_LARICIO"

• "TAXUS_BACCATA"

• "ACER_PLATANOIDES"

• "ACER_CAMPESTRE"

• "SORBUS_AUCUPARIA"

• "JUNGLANS_SP"

• "TILLIA_SP"

• "PICEA_SITCHENSIS"

• "ABIES_ALBA"

• "TSUGA_CANADENSIS"

• "ABIES_GRANDIS"

• "CUPRESSUS_SP"

• "THUJA_PLICATA"

• "AESCULUS_HIPPOCASTANUM"

• "ROBINIA_PSEUDOACACIA"

• "SALIX_SP"

Details

The function:

• checks that the input data frame contains the required columns c130, htot and species_code,

• validates that all species codes are present in the dan2 table,

• merges the input data with dan2 to retrieve: coeff_a, coeff_b, coeff_c, coeff_d, coeff_e, coeff_f, as well as the species-specific valid ranges: min_c130, max_c130, min_htot, max_htot,

• issues a warning for trees whose c130 is outside the valid range [min_c130, max_c130],

• issues a warning for trees whose htot is outside the valid range [min_htot, max_htot],

• computes the tarif 2 volume using the species-specific polynomial: $$ v_{c,22} = coeff_a + coeff_b \cdot c130 + coeff_c \cdot c130^2 + coeff_d \cdot c130^3 + coeff_e \cdot htot + coeff_f \cdot c130^2 \cdot htot $$

Species codes must match those available in the dan2 reference table. If one or more species are not found, the function issues a warning.

For trees where c130 or htot is outside the species-specific validity ranges [min_c130, max_c130] and [min_htot, max_htot], warnings are issued, but the volume is still computed.

See Also

dan2 for the species-specific coefficients and ranges.

Examples

df <- data.frame(
  c130         = c(145, 156, 234, 233),
  htot         = c(25, 23, 45, 34),
  species_code = c("PINUS_SYLVESTRIS", "QUERCUS_RUBRA",
                   "QUERCUS_SP", "FAGUS_SYLVATICA")
)
dagnelie_vc22_2(data = df)