Commonly Used Parameter Setting

In ZOOclient, The type Parameter defines all parameters used in the optimization algorithms. Commonly, five parameters are needed to be manually determined by users. Respectively are budget, evaluation_server_num, control_server_ip_port, objective_file and func.

par = Parameter(budget=10000, evaluation_server_num=10, control_server_ip_port="192.168.1.105:20000", 
objective_file="fx.py", func="ackley")

• budget means the number of calls to the objective function.
• evaluation_server_num is the number of evaluation servers client requires.
• control_server_ip_port is the control server's ip:port.
• objective_file is the file containing the objective funtion.
• func is the name of the objective function

The default algorithm used in ZOOclient is ASRacos (Asynchronous Sequential Racos). To use PPOSS method(Parallel Pareto Optimization for Subset Selection, IJCAI'16), the other method implemented in ZOOclient, the parameterconstraint="constraint_function_name" is needed and the constraint function should be defined in objective_file as well.

par = Parameter(budget=10000, evaluation_server_num=10, control_server_ip_port="192.168.1.105:20000", 
objective_file="sparse_mse.py", func="target_func")

Optional Parameters

1. init_sample

   init_set = [Solution(x = [...]), Solution(x = [...]), ...]
   par = Parameter(..., init_sample=init_set, ...)

   In some cases, users don't want to start the optimization from scratch. init_sample parameter is set for initiatial sample used by ZOOclient. Some known good solutions can be added in this set. The number of the solutions is unlimited.

2. show_x

   par = Parameter(..., show_x=true, ...)

   If show_x is set to true, ZOOclient will print the best solution's x as well as value every 10 seconds. Otherwise, best solution's x will not be printed.

3. output_file

   par = Parameter(..., output_file="log.txt", ...)

   If output_file is set, ZOOclient will output the the best solution's value every 10 seconds to this file. If show_x is true, best solution's x is also be output.