decide¶
Commands and settings related to the selection of operators during the Soar decision process
Synopsis¶
Summary Screen¶
Using the decide command without any arguments will display key elements of
Soar's current decision settings:
decide numeric-indifferent-mode¶
The numeric-indifferent-mode command sets how multiple numeric indifferent
preference values given to an operator are combined into a single value for use
in random selection.
The default procedure is --sum which sums all numeric indifferent preference
values given to the operator, defaulting to 0 if none exist. The alternative
--avg mode will average the values, also defaulting to 0 if none exist.
decide indifferent-selection¶
The indifferent-selection command allows the user to set options relating to
selection between operator proposals that are mutually indifferent in preference
memory.
The primary option is the exploration policy (each is covered below). When Soar starts, softmax is the default policy.
Note: As of version 9.3.2, the architecture no longer automatically changes the policy to epsilon-greedy the first time Soar-RL is enabled.
Some policies have parameters to temper behavior. The indifferent-selection command provides basic facilities to automatically reduce these parameters exponentially and linearly each decision cycle by a fixed rate. In addition to setting these policies/rates, the auto-reduce option enables the automatic reduction system (disabled by default), for which the Soar decision cycle incurs a small performance cost.
indifferent-selection options¶
| Option | Description |
|---|---|
-s, --stats |
Summary of settings |
policy |
Set exploration policy |
parameter [exploration policy parameters] |
Get/Set exploration policy parameters (if value not given, returns the current value) |
parameter [reduction_policy](value] |
Get/Set exploration policy parameter reduction policy (if policy not given, returns the current) |
parameter reduction_policy [exploration policy parameter] |
Get/Set exploration policy parameter reduction rate for a policy (if rate not give, returns the current) |
-a, --auto-reduce [on,off](reduction-rate] |
Get/Set auto-reduction setting (if setting not provided, returns the current) |
indifferent-selection exploration policies¶
| Option | Description |
|---|---|
-b, --boltzmann |
Tempered softmax (uses temperature) |
-g, --epsilon-greedy |
Tempered greedy (uses epsilon) |
-x, --softmax |
Random, biased by numeric indifferent values (if a non-positive value is encountered, resorts to a uniform random selection) |
-f, --first |
Deterministic, first indifferent preference is selected |
-l, --last |
Deterministic, last indifferent preference is selected |
indifferent-selection exploration policy parameters¶
| Parameter Name | Acceptable Values | Default Value |
|---|---|---|
-e, --epsilon |
[0, 1] |
0.1 |
-t, --temperature |
(0, inf) |
25 |
indifferent-selection auto-reduction policies¶
| Parameter Name | Acceptable Values | Default Value |
|---|---|---|
exponential default |
[0, 1] |
1 |
linear |
[0, inf] |
0 |
decide predict¶
The predict command determines, based upon current operator proposals, which operator will be chosen during the next decision phase. If predict determines an operator tie will be encountered, "tie" is returned. If predict determines no operator will be selected (state no-change), "none" is returned. If predict determines a conflict will arise during the decision phase, "conflict" is returned. If predict determines a constraint failure will occur, "constraint" is returned. Otherwise, predict will return the id of the operator to be chosen. If operator selection will require probabilistic selection, and no alterations to the probabilities are made between the call to predict and decision phase, predict will manipulate the random number generator to enforce its prediction.
decide select¶
The select command will force the selection of an operator, whose id is supplied as an argument, during the next decision phase. If the argument is not a proposed operator in the next decision phase, an error is raised and operator selection proceeds as if the select command had not been called. Otherwise, the supplied operator will be selected as the next operator, regardless of preferences. If select is called with no id argument, the command returns the operator id currently forced for selection (by a previous call to select), if one exists.
Example¶
Assuming operator "O2" is a valid operator, this would select it as the next operator to be selected:
decide set-random-seed¶
Seeds the random number generator with the passed seed. Calling decide
set-random-seed (or equivalently, decide srand) without providing a seed will
seed the generator based on the contents of /dev/urandom (if available) or else
based on time() and clock() values.