Package net.simplace.sim.components.experimental.livestock

Class LivestockFunctions

java.lang.Object
net.simplace.sim.components.experimental.livestock.LivestockFunctions
public class LivestockFunctions extends Object
Functions to calculate Livestock population See: M. Lesnoff, 2008, DynMod: A tool for demographic projections of tropical Livestock population under Microsoft Excel, User Manual, Version 1. CIRAD, ILRI
Author:
Gunther Krauss

  • Constructor Details

    • LivestockFunctions

      public LivestockFunctions()

  • Method Details

    • HfromP

      public static double HfromP(double p, double p2)
      Calculate hazard rate from probabilities
      Parameters:
      p - probability
      p2 - concurrent probability
      Returns:
      hazard rate

    • PfromH

      public static double PfromH(double h, double h2)
      Calculate probability from hazard rates
      Parameters:
      h - hazard rate
      h2 - concurrent hazard rate
      Returns:
      probability

    • HfromPOld

      public static double HfromPOld(double po, double pd)
      Estimates offtake hazard rate approximately from offtake and death probability ho and hd are dependent on po and ph, and therefore an equation system has to be solved. This method estimates hd by ignoring po and uses it to calculate ho by a root finding algorithm.
      Parameters:
      po - offtake probability
      pd - death probability
      Returns:
      offtake hazard rate

    • PRescaled

      public static double PRescaled(double p, double p2, double n)
      Rescales probability to different time unit
      Parameters:
      p - probability
      p2 - concurrent probability
      n - steps
      Returns:
      rescaled probability

    • surv

      public static double surv(double pd, double po)
      Calculates survive probability
      Parameters:
      pd - death probability
      po - offtake probability
      Returns:
      survive probability

    • gamma

      public static double gamma(double surv, double d)
      Calculates the transition probability from one age class to the next one
      Parameters:
      surv - survive probability
      d - duration of ageclass in timeunits
      Returns:
      transition probability

    • calculatePopulationRates

      public static LivestockFunctions.PopulationRates calculatePopulationRates(Double[] state, Double[] pdeath, Double[] pofftake, Double[] duration, Double[] intake, Double productionNutritionIndex, Double maintenanceNutritionIndex, Double MaintenanceNutritionMortalityFactor, Double[] aMax, Double prol, Double parturition, Double femaleproportion, int n)
      Rate function for livestock
      Parameters:
      state - array of actual states [animal]
      pdeath - array of death probabilities on yearly base [-]
      pofftake - array of death probabilities on yearly base [-] //TODO: change calculation: fraction daywise!
      duration - array of age class durations [year] //TODO: day?
      intake - array of yearly intake [animal day-1]
      productionNutritionIndex - limit population growth [0-1]
      maintenanceNutritionIndex - rises population death rate [0-1]
      aMax - array of maximal animal number [animal]
      prol - prolification rate [-]
      parturition - parturition rate [year-1]
      femaleproportion - proportion of females at birth [-]
      n - number of time steps per year [-]
      Returns:
      record containing the arrays with overall change rate dRate, dBirth, dDeath, dIntake, dOfftake [animal day-1], as well as Balance array with total, female and male balance

    • calculatePopulationRatesExcelCompatible

      public static LivestockFunctions.PopulationRatesExtra calculatePopulationRatesExcelCompatible(Double[] state, Double[] pdeath, Double[] pofftake, Double[] duration, Double[] intake, Double[] aMax, Double prol, Double parturition, Double femaleproportion, int n)
      Rate function for livestock (compatibility mode) Perform same calculation as in the Excel version. Differences are - sligthtly inaccurate rescaling of probabilities - calculating birth rates from next step's rate - estimate next step's rate to limit to maximal values The effect of using premature states for some rate calculations becomes negligible when calculating with higher timesteps (e.g. daily)
      Parameters:
      state - array of actual states [animal]
      pdeath - array of death probabilities on yearly base [-]
      pofftake - array of death probabilities on yearly base [-]
      duration - array of age class durations [year]
      intake - array of yearly intake [animal day-1]
      aMax - array of maximal animal number [animal]
      prol - prolification rate [-]
      parturition - parturition rate [year-1]
      femaleproportion - proportion of females at birth [-]
      n - number of time steps per year [-]
      Returns:
      record containing the arrays with overall change rate dRate, dBirth, dDeath, dIntake, dOfftake, dDeathNewBorn, dOfftakeNewBorn [animal day-1], as well as Balance array with total, female and male balance