Getting started

After installation, the TAS server can be started with a default or manual configuration. Currently, an instance of GPRTASServer is used which implements the methodology described in the reference.

Run server

Run ariane-tas-server.

ariane-tas-server [-h] [-c CONFIG_FILE] [-s RANDOM_SEED] [-p PORT] [--version]

Start ARIANE server

optional arguments:
    -h, --help                                 show this help message and exit
    -c CONFIG_FILE, --config_file CONFIG_FILE  path to configuration file
    -s RANDOM_SEED, --random_seed RANDOM_SEED  seed for pseudo-random numbers
    -p PORT, --port PORT                       port number
    --version                                  show program's version number and exit

The following output should be visible:

(venv) user@host:path/to/folder$ ariane-tas-server
[server] Start GPRTASServer...
[server] GPRTASServer started.
[server] Wait for requests...

The server is now ready to receive requests from the client. For every experiment that is started by the client, the server creates .json files under logs/ to store acquired experimental data. In a typical workflow, three different experiment files are stored per experiment, each containing the same types of information:

  1. *_0_init.json (after initialization)

  2. *_1_interm.json (during the experiment after each new measurement point to store most current data)

  3. *_2_final.json (after the experiment)

These files are used to diagnose an experiment (see Diagnostics).

Configuration

The GPRTASServer can be configured by a .cfg configuration file with a corresponding section ariane-tas-server-gpr. For a list of available parameters, see Tab. 1 in the reference. The following table shows all parameters and brief descriptions. Any, except the first, parameter in the table is used for the server and thus can be set in the configuration file. The first parameter, \(N_{\textnormal{row}}\), needs to be set in the client.

Parameter

Notation

Description

\(N_{\textnormal{row}}\)

Number of rows in initialization grid, needs to be set in the client (default value is 11)

level_backgr_diffs_rel_max

\(\Delta^{\textnormal{rel}}_{\max}\)

Parameter for estimation of background level, see Eq. (45)

level_backgr_diffs_abs_min

\(\Delta^{\textnormal{abs}}_{\min}\)

Parameter for estimation of background level, see Eq. (45)

level_backgr_decile_max

\(l_{\max}\)

Maximum decile in estimation for backgroud level, see Eq. (45)

thresh_intens_fact

\(\beta\)

Parameter for estimation of intensity threshold, see Eq. (47)

num_kernel_optim_restarts

\(N_{\mathcal{H}}\)

Number of restarts of local kernel optimizations for a single global kernel optimization with GaussianProcessRegressor from scikit-learn

kernel_variance_bounds_min

Minimum value of kernel variance parameter

kernel_variance_bounds_max

Maximum value of kernel variance parameter

kernel_length_scales_bounds_min

Minimum value of kernel length scale parameters

kernel_length_scales_bounds_max

Maximum value of kernel length scale parameters

num_kernel_optims_min

\(N_{\textnormal{KO}}^{\min}\)

Minimum number of kernel optimizations

num_kernel_optims_max

\(N_{\textnormal{KO}}^{\max}\)

Maximum number of kernel optimizations

kernel_optims_stop_num_last

\(k_{\textnormal{KO}}\)

Parameter for stopping criterion for kernel optimizations, see Eq. (57)

kernel_optims_stop_eps

\(\varepsilon_{\textnormal{KO}}\)

Parameter for stopping criterion for kernel optimizations, see Eq. (57)

length_scales_min_fact

\(\delta^{-}\)

Parameter for detection of degenerate cases, see Eq. (64)

length_scales_max_fact

\(\delta^{+}\)

Parameter for detection of degenerate cases, see Eq. (64)

By default, ARIANE uses the configuration file $VENV_ROOT/config/ariane-tas-server-gpr.cfg in the root directory of your Python environment. The default parameter values set in this configuration file correspond to the values specified in Tab. 1 in the reference.

config/ariane-tas-server-gpr.cfg
[ariane-tas-server-gpr]
level_backgr_diffs_rel_max = 0.5
level_backgr_diffs_abs_min = 15
level_backgr_decile_max = 6
thresh_intens_fact = 0.5
num_kernel_optim_restarts = 100
kernel_variance_bounds_min = 1e-3
kernel_variance_bounds_max = 1e2
kernel_length_scales_bounds_min = 1e-3
kernel_length_scales_bounds_max = 1e2
num_kernel_optims_min = 25
num_kernel_optims_max = 75
kernel_optims_stop_num_last = 9
kernel_optims_stop_eps = 0.025
length_scales_min_fact = 1e-3
length_scales_max_fact = 1.