Growth ---------------------------------------- Individuals of a given school are assumed to grow in size and weight at a given time only when the amount of food they ingested fulfill maintenance requirements, i.e., only when their predation efficiency at that time is greater than the predation efficiency ensuring body maintenance of school. .. math:: G(s, a) = M_{\Delta}(s, a) \times \frac{S_R(s, a) - C_{S_R}(s)} {1 - C_{S_R}(s)}\ if\ S_R(s, a) \ge C_{S_R} G(s, a) = 0\ if\ S_R(s, a) \lt C_{S_R} with :math:C_{S_R} is the critical predation efficiency and :math:S_R the predation success rate of the school. :math:M_{\Delta}(s, a) = \lambda \times \Delta L(a) is the maximum growth rate at age :math:a and for species :math:s. :math:\Delta L(a) = L(a + 1) - L(a) is the mean length increase determined from a growth function (Von Bertalanffy or Gompertz growth function), while :math:\lambda is a factor that allows to control the maximum length at a given age. .. index:: growth.java.classname.sp#, predation.efficiency.critical.sp#, species.delta.lmax.factor.sp# .. table:: Growth parameters :align: center .. csv-table:: :delim: ; growth.java.classname.sp# ; Class name of the age to length conversion predation.efficiency.critical.sp# ; Critical predation success (:math:C_{S_R}) species.delta.lmax.factor.sp# ; :math:\lambda (default = 2) .. ipython:: python :suppress: import os import subprocess cwd = os.getcwd() fpath = "osmose/process/_static/plot_growth.py" with open(fpath) as f: with open(os.devnull, "w") as DEVNULL: subprocess.call(["python", fpath]) Von Bertalanffy growth @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ When the :samp:growth.java.classname.sp# is equal to :samp:fr.ird.osmose.process.growth.VonBertalanffyGrowth.java, a von Bertalanffy growth function is used. **It is the defaut one.** .. math:: L(a) = L_{egg}\ if\ a=0 L(a) = L_{egg} + (L_{thres} - L_{egg}) \times \left(\frac{a}{a_{thres}}\right)\ if\ a>0\ \&\ a0\ \& aa_{exp}\ \&\ a