/**
* Multiple Staircase Trial Handler
*
* @author Alain Pitiot
* @version 2021.2.3
* @copyright (c) 2017-2020 Ilixa Ltd. (http://ilixa.com) (c) 2020-2022 Open Science Tools Ltd.
* (https://opensciencetools.org)
* @license Distributed under the terms of the MIT License
*/
import {TrialHandler} from "./TrialHandler.js";
import {QuestHandler} from "./QuestHandler.js";
import * as util from "../util/Util.js";
import seedrandom from "seedrandom";
/**
* <p>A handler dealing with multiple staircases, simultaneously.</p>
*
* <p>Note that, at the moment, using the MultiStairHandler requires the jsQuest.js
* library to be loaded as a resource, at the start of the experiment.</p>
*
* @extends TrialHandler
*/
export class MultiStairHandler extends TrialHandler
{
/**
* @memberof module:data
* @param {Object} options - the handler options
* @param {module:core.PsychoJS} options.psychoJS - the PsychoJS instance
* @param {string} options.varName - the name of the variable / intensity / contrast
* / threshold manipulated by the staircases
* @param {MultiStairHandler.StaircaseType} [options.stairType="simple"] - the
* handler type
* @param {Array.<Object> | String} [options.conditions= [undefined] ] - if it is a string,
* we treat it as the name of a conditions resource
* @param {module:data.TrialHandler.Method} options.method - the trial method
* @param {number} [options.nTrials=50] - maximum number of trials
* @param {number} options.randomSeed - seed for the random number generator
* @param {string} options.name - name of the handler
* @param {boolean} [options.autoLog= false] - whether or not to log
*/
constructor({
psychoJS,
varName,
stairType,
conditions,
method = TrialHandler.Method.RANDOM,
nTrials = 50,
randomSeed,
name,
autoLog
} = {})
{
super({
psychoJS,
name,
autoLog,
seed: randomSeed,
// note: multiStairHandler is a sequential TrialHandler, we deal with randomness
// in _nextTrial
method: TrialHandler.Method.SEQUENTIAL,
trialList: Array(nTrials),
nReps: 1
});
// now that we have initialised a sequential TrialHandler, we update method:
this._multiMethod = method;
this._addAttribute("varName", varName);
this._addAttribute("stairType", stairType, MultiStairHandler.StaircaseType.SIMPLE);
this._addAttribute("conditions", conditions, [undefined]);
this._addAttribute("nTrials", nTrials);
if (typeof randomSeed !== "undefined")
{
this._randomNumberGenerator = seedrandom(randomSeed);
}
else
{
this._randomNumberGenerator = seedrandom();
}
this._prepareStaircases();
this._nextTrial();
}
/**
* Get the current staircase.
*
* @returns {TrialHandler} the current staircase, or undefined if the trial has ended
*/
get currentStaircase()
{
return this._currentStaircase;
}
/**
* Get the current intensity.
*
* @returns {number} the intensity of the current staircase, or undefined if the trial has ended
*/
get intensity()
{
if (this._currentStaircase instanceof QuestHandler)
{
return this._currentStaircase.getQuestValue();
}
// TODO similar for simple staircase:
// if (this._currentStaircase instanceof StaircaseHandler)
// {
// return this._currentStaircase.getStairValue();
// }
return undefined;
}
/**
* Add a response to the current staircase.
*
* @param{number} response - the response to the trial, must be either 0 (incorrect or
* non-detected) or 1 (correct or detected)
* @param{number | undefined} [value] - optional intensity / contrast / threshold
*/
addResponse(response, value)
{
// check that response is either 0 or 1:
if (response !== 0 && response !== 1)
{
throw {
origin: "MultiStairHandler.addResponse",
context: "when adding a trial response",
error: `the response must be either 0 or 1, got: ${JSON.stringify(response)}`
};
}
this._psychoJS.experiment.addData(this._name+'.response', response);
if (!this._finished)
{
// update the current staircase, but do not add the response again:
this._currentStaircase.addResponse(response, value, false);
// move onto the next trial:
this._nextTrial();
}
}
/**
* Validate the conditions.
*
* @protected
*/
_validateConditions()
{
try
{
// conditions must be a non empty array:
if (!Array.isArray(this._conditions) || this._conditions.length === 0)
{
throw "conditions should be a non empty array of objects";
}
// TODO this is temporary until we have implemented StairHandler:
if (this._stairType === MultiStairHandler.StaircaseType.SIMPLE)
{
throw "'simple' staircases are currently not supported";
}
for (const condition of this._conditions)
{
// each condition must be an object:
if (typeof condition !== "object")
{
throw "one of the conditions is not an object";
}
// each condition must include certain fields, such as startVal and label:
if (!("startVal" in condition))
{
throw "each condition should include a startVal field";
}
if (!("label" in condition))
{
throw "each condition should include a label field";
}
// for QUEST, we also need startValSd:
if (this._stairType === MultiStairHandler.StaircaseType.QUEST && !("startValSd" in condition))
{
throw "QUEST conditions must include a startValSd field";
}
}
}
catch (error)
{
throw {
origin: "MultiStairHandler._validateConditions",
context: "when validating the conditions",
error
};
}
}
/**
* Setup the staircases, according to the conditions.
*
* @protected
*/
_prepareStaircases()
{
try
{
this._validateConditions();
this._staircases = [];
for (const condition of this._conditions)
{
let handler;
// QUEST handler:
if (this._stairType === MultiStairHandler.StaircaseType.QUEST)
{
const args = Object.assign({}, condition);
args.psychoJS = this._psychoJS;
args.varName = this._varName;
// label becomes name:
args.name = condition.label;
args.autoLog = this._autoLog;
if (typeof condition.nTrials === "undefined")
{
args.nTrials = this._nTrials;
}
handler = new QuestHandler(args);
}
// simple StairCase handler:
if (this._stairType === MultiStairHandler.StaircaseType.SIMPLE)
{
// TODO not supported just yet, an exception is raised in _validateConditions
continue;
}
this._staircases.push(handler);
}
this._currentPass = [];
this._currentStaircase = null;
}
catch (error)
{
throw {
origin: "MultiStairHandler._prepareStaircases",
context: "when preparing the staircases",
error
};
}
}
/**
* Move onto the next trial.
*
* @protected
*/
_nextTrial()
{
try
{
// if the current pass is empty, get a new one:
if (this._currentPass.length === 0)
{
this._currentPass = this._staircases.filter( handler => !handler.finished );
if (this._multiMethod === TrialHandler.Method.SEQUENTIAL)
{
// nothing to do
}
else if (this._multiMethod === TrialHandler.Method.RANDOM)
{
this._currentPass = util.shuffle(this._currentPass, this._randomNumberGenerator);
}
else if (this._multiMethod === TrialHandler.Method.FULL_RANDOM)
{
if (this._currentPass.length > 0)
{
// select a handler at random:
const index = Math.floor(this._randomNumberGenerator() * this._currentPass.length);
const handler = this._currentPass[index];
this._currentPass = [handler];
}
}
}
// pick the next staircase in the pass:
this._currentStaircase = this._currentPass.shift();
// test for termination:
if (typeof this._currentStaircase === "undefined")
{
this._finished = true;
// update the snapshots associated with the current trial in the trial list:
for (let t = 0; t < this._snapshots.length - 1; ++t)
{
// the current trial is the last defined one:
if (typeof this._trialList[t + 1] === "undefined")
{
this._snapshots[t].finished = true;
break;
}
}
return;
}
// get the value, based on the type of the trial handler:
let value = Number.MIN_VALUE;
if (this._currentStaircase instanceof QuestHandler)
{
value = this._currentStaircase.getQuestValue();
}
// TODO add a test for simple staircase:
// if (this._currentStaircase instanceof StaircaseHandler)
// {
// value = this._currentStaircase.getStairValue();
// }
this._psychoJS.logger.debug(`selected staircase: ${this._currentStaircase.name}, estimated value for variable ${this._varName}: ${value}`);
// update the next undefined trial in the trial list, and the associated snapshot:
for (let t = 0; t < this._trialList.length; ++t)
{
if (typeof this._trialList[t] === "undefined")
{
this._trialList[t] = {
[this._name+"."+this._varName]: value,
[this._name+".intensity"]: value
};
for (const attribute of this._currentStaircase._userAttributes)
{
// "name" becomes "label" again:
if (attribute === "name")
{
this._trialList[t][this._name+".label"] = this._currentStaircase["_name"];
}
else if (attribute !== "trialList" && attribute !== "extraInfo")
{
this._trialList[t][this._name+"."+attribute] = this._currentStaircase["_" + attribute];
}
}
if (typeof this._snapshots[t] !== "undefined")
{
let fieldName = /*this._name + "." +*/ this._varName;
this._snapshots[t][fieldName] = value;
this._snapshots[t].trialAttributes.push(fieldName);
fieldName = /*this._name + ".*/ "intensity";
this._snapshots[t][fieldName] = value;
this._snapshots[t].trialAttributes.push(fieldName);
for (const attribute of this._currentStaircase._userAttributes)
{
// "name" becomes "label" again:
if (attribute === 'name')
{
fieldName = /*this._name + ".*/ "label";
this._snapshots[t][fieldName] = this._currentStaircase["_name"];
this._snapshots[t].trialAttributes.push(fieldName);
}
else if (attribute !== 'trialList' && attribute !== 'extraInfo')
{
fieldName = /*this._name+"."+*/ attribute;
this._snapshots[t][fieldName] = this._currentStaircase["_" + attribute];
this._snapshots[t].trialAttributes.push(fieldName);
}
}
}
break;
}
}
}
catch (error)
{
throw {
origin: "MultiStairHandler._nextTrial",
context: "when moving onto the next trial",
error
};
}
}
}
/**
* MultiStairHandler staircase type.
*
* @enum {Symbol}
* @readonly
*/
MultiStairHandler.StaircaseType = {
/**
* Simple staircase handler.
*/
SIMPLE: Symbol.for("SIMPLE"),
/**
* QUEST handler.
*/
QUEST: Symbol.for("QUEST")
};
/**
* Staircase status.
*
* @enum {Symbol}
* @readonly
*/
MultiStairHandler.StaircaseStatus = {
/**
* The staircase is currently running.
*/
RUNNING: Symbol.for("RUNNING"),
/**
* The staircase is now finished.
*/
FINISHED: Symbol.for("FINISHED")
};