Revised 2007-07-07 BEB

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Energy Model


The energy model provides an organism with a metabolic rate, which is proportional to its stored energy (shown below). An organism with a higher metabolic rate will pay more energy to execute instructions than one with a lower rate. An organism must pay both virtual CPU cycle and energy costs to execute instructions. As instructions are executed the organism's stored energy level is reduced. Energy can be taken up by the organism when it completes a task, among others.

Metabolic Rate = Stored Energy / NUM_INST_EXC_BEFORE_0_ENERGY


The settings below are defults from avida.cfg

# Energy Settings
ENERGY_ENABLED 0                       # Enable Energy Model. 0/1 (off/on)
ENERGY_GIVEN_ON_INJECT 0               # Energy given to organism upon injection.
ENERGY_GIVEN_AT_BIRTH 0                # Energy given to offspring upon birth.
FRAC_PARENT_ENERGY_GIVEN_AT_BIRTH 0.5  # Fraction of perent's energy given to offspring.
FRAC_ENERGY_DECAY_AT_BIRTH 0.0         # Fraction of energy lost due to decay during reproduction.
NUM_INST_EXC_BEFORE_0_ENERGY 0         # Number of instructions executed before energy is exhausted.
ENERGY_CAP -1                          # Maximum amount of energy that can be stored in an organism.
                                       # -1 means the cap is set to Max Int
APPLY_ENERGY_METHOD 0                  # When should rewarded energy be applied to current energy?
                                       # 0 = on divide
                                       # 1 = on completion of task
                                       # 2 = on sleep
FRAC_ENERGY_TRANSFER 0.0               # Fraction of replaced organism's energy take by new resident
LOG_SLEEP_TIMES 0                      # Log sleep start and end times. 0/1 (off/on)
                                       # WARNING: may use lots of memory.

Description of Settings


Flag that disables/enables the us of the energy model. 0 = off, 1 = on


How much energy is given to an injected organism. This number should be large enough to sustain the population until it can gather its own energy through tasks, etc..


How much energy is given to an organism when it is born.


Fraction of the parent(s) energy which is taken from the parent and given to the offspring at birth.


Fraction of energy that decays on birth.


Number of instructions an organism can execute before it runs out of energy assuming no new energy. Note: if instructions have energy costs > 0 then this options needs to be altered accordingly.


Maximum amount of energy that can be stored in an organism.


Specifies when newly received energy is applied to the organism energy store and metabolic rate. Note: the sleep instruction can also be used as an eat instructions if needed.


Fraction of a replaced organism's energy transfered to the replacing organism.


Logs start and end times, in updates, of all executions of the sleep instruction. Note: can use a lot of memory.

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