Learn R Programming

landsepi (version 1.1.1)

epid_output: Generation of epidemiological and economic model outputs

Description

Generates epidemiological and economic outputs from model simulations.

Usage

epid_output(
  types = "all",
  time_param,
  Npatho,
  area,
  rotation,
  croptypes,
  cultivars_param,
  eco_param,
  GLAnoDis = cultivars_param$max_density[1],
  ylim_param = list(audpc = c(0, 0.76), audpc_rel = c(0, 1), gla = c(0, 1.48), gla_rel
    = c(0, 1), eco_cost = c(0, NA), eco_yield = c(0, NA), eco_product = c(0, NA),
    eco_margin = c(NA, NA)),
  writeTXT = TRUE,
  graphic = TRUE,
  path = getwd()
)

Arguments

types

a character string (or a vector of character strings if several outputs are to be computed) specifying the type of outputs to generate (see details):

  • "audpc": Area Under Disease Progress Curve

  • "audpc_rel": Relative Area Under Disease Progress Curve

  • "gla": Green Leaf Area

  • "gla_rel": Relative Green Leaf Area

  • "eco_yield": Total crop yield

  • "eco_cost": Operational crop costs

  • "eco_product": Crop products

  • "eco_margin": Margin (products - operational costs)

  • "HLIR_dynamics", "H_dynamics", "L_dynamics", "IR_dynamics", "HLI_dynamics", etc.: Epidemic dynamics related to the specified sanitary status (H, L, I or R and all their combinations). Graphics only, works only if graphic=TRUE.

  • "all": compute all these outputs (default).

time_param

list of simulation parameters:

  • Nyears = number cropping seasons,

  • nTSpY = number of time-steps per cropping season.

Npatho

number of pathogen genotypes.

area

a vector containing polygon areas (must be in square meters).

rotation

a dataframe containing for each field (rows) and year (columns, named "year_1", "year_2", etc.), the index of the cultivated croptype. Importantly, the matrix must contain 1 more column than the real number of simulated years.

croptypes

a dataframe with three columns named 'croptypeID' for croptype index, 'cultivarID' for cultivar index and 'proportion' for the proportion of the cultivar within the croptype.

cultivars_param

list of parameters associated with each host genotype (i.e. cultivars):

  • name = vector of cultivar names,

  • initial_density = vector of host densities (per square meter) at the beginning of the cropping season as if cultivated in pure crop,

  • max_density = vector of maximum host densities (per square meter) at the end of the cropping season as if cultivated in pure crop,

  • cultivars_genes_list = a list containing, for each host genotype, the indices of carried resistance genes.

eco_param

a list of economic parameters for each host genotype as if cultivated in pure crop:

  • yield_perHa = a dataframe of 4 columns for the theoretical yield associated with hosts in sanitary status H, L, I and R, as if cultivated in pure crops, and one row per host genotype (yields are expressed in weight or volume units / ha / cropping season),

  • planting_cost_perHa = a vector of planting costs (in monetary units / ha / cropping season),

  • market_value = a vector of market values of the production (in monetary units / weight or volume unit).

GLAnoDis

the value of absolute GLA in absence of disease (required to compute economic outputs).

ylim_param

a list of graphical parameters for each required output: bounds for y-axes for audpc, gla, gla_rel, eco_cost, eco_yield, eco_product, eco_margin.

writeTXT

a logical indicating if the output is written in a text file (TRUE) or not (FALSE).

graphic

a logical indicating if a tiff graphic of the output is generated (only if more than one year is simulated).

path

path of text file (if writeTXT = TRUE) and tiff graphic (if graphic = TRUE) to be generated.

Value

A list containing, for each required type of output, a matrix summarising the output for each year and cultivar (as well as the whole landscape). Each matrix can be written in a txt file (if writeTXT=TRUE), and illustrated in a graphic (if graphic=TRUE).

Details

Outputs are computed every year for every cultivar as well as for the whole landscape.

Epidemiological outputs.

The epidemiological impact of pathogen spread can be evaluated by different measures:

  1. Area Under Disease Progress Curve (AUDPC): average number of diseased host individuals (status I + R) per time step and square meter.

  2. Relative Area Under Disease Progress Curve (AUDPCr): average proportion of diseased host individuals (status I + R) relative to the total number of existing hosts (H+L+I+R).

  3. Green Leaf Area (GLA): average number of healthy host individuals (status H) per time step and per square meter.

  4. Relative Green Leaf Area (GLAr): average proportion of healthy host individuals (status H) relative to the total number of existing hosts (H+L+I+R).

Economic outputs.

The economic outcome of a simulation can be evaluated using:

  1. Crop yield: yearly crop yield (e.g. grains, fruits, wine) in weight (or volume) units per hectare (depends on the number of productive hosts and associated theoretical yield).

  2. Crop products: yearly product generated from sales, in monetary units per hectare (depends on crop yield and market value).

  3. Operational crop costs: yearly costs associated with crop planting in monetary units per hectare (depends on initial host density and planting cost).

  4. Crop margin, i.e. products - operational costs, in monetary units per hectare.

References

Rimbaud L., Papa<U+00EF>x J., Rey J.-F., Barrett L. G. and Thrall P. H. (2018). Assessing the durability and efficiency of landscape-based strategies to deploy plant resistance to pathogens. PLoS Computational Biology 14(4):e1006067.

See Also

evol_output

Examples

Run this code
# NOT RUN {
demo_landsepi()
# }

Run the code above in your browser using DataLab