Translating pseudorandom function to PsychoJS

Online experiments
1

I created an experiment in Builder where I want my stimuli to be presented in pseudorandom order, e.g. without presenting more than 3 stimuli in the same condition in a row. I added a function called pseudoRand() in a Begin Experiment code component, adapted from here: Pseudo-randomization of stimuli trials in a loop

The following function works locally using PsychoPy:

import random

def pseudoRand(excelFile):

    # Load trials
    trials=data.importConditions(excelFile)
    conditionMet = False
    # Pseudo-randomize trials
    while conditionMet == False:
        random.shuffle(trials)
        conditions = []
        for row in range(len(trials)):
            conditions.append(trials[row]["stim_type"])  #Name of the conditions type column
        # Condition for pseudo-randomization: No consecutive same type
        for row in range(len(trials) - 3):
            if trials[row]["stim_type"] == trials[row + 1]["stim_type"] and trials[row]["stim_type"] == trials[row + 2]["stim_type"] and trials[row]["stim_type"] == trials[row + 3]["stim_type"]:
                conditionMet = False
                break
            elif trials[row]["question_num"] == trials[row + 1]["question_num"] and trials[row]["question_num"] == trials[row + 2]["question_num"] and trials[row]["question_num"] == trials[row + 3]["question_num"]:
                conditionMet = False
                break
            elif trials[row]["target_num"] == trials[row + 1]["target_num"] and trials[row]["target_num"] == trials[row + 2]["target_num"] and trials[row]["target_num"] == trials[row + 3]["target_num"]:
                conditionMet = False
                break
            elif trials[row]["target_phoneme"] == trials[row + 1]["target_phoneme"] and trials[row]["target_phoneme"] == trials[row + 2]["target_phoneme"] and trials[row]["target_phoneme"] == trials[row + 3]["target_phoneme"]:
                conditionMet = False
                break
            else:
                conditionMet = True
    # Save the final order of the trials
    customOrder = []
    for row in range(len(trials)):
        customOrder.append(trials[row]["stim_order"]) #Name of the original index column
    return customOrder

The function creates new random orders until all conditions are met (no more than 3 trials in each of the conditions of interest, namely “stim_type”, “question_num”, “target_num” and “target_phoneme”). I then call the function in the “Selected rows” property of my trial loop as:

$pseudoRand('List1_stim_data.csv')

To upload the experiment to Pavlovia, I edited the function in PsychoJS as follows:

shuffle = util.shuffle;
pseudoRand = function(excelFile) {
    var conditionMet, conditions, customOrder, trials;
    trials = data.importConditions(excelFile);
    conditionMet = false;
    while ((conditionMet === false)) {
        shuffle(trials);
        conditions = [];
        for (var row, _pj_c = 0, _pj_a = util.range(trials.length), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
            row = _pj_a[_pj_c];
            conditions.push(trials[row]["stim_type"]);
        }
        for (var row, _pj_c = 0, _pj_a = util.range((trials.length - 3)), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
            row = _pj_a[_pj_c];
            if ((((trials[row]["stim_type"] === trials[(row + 1)]["stim_type"]) && (trials[row]["stim_type"] === trials[(row + 2)]["stim_type"])) && (trials[row]["stim_type"] === trials[(row + 3)]["stim_type"]))) {
                conditionMet = false;
                break;
            } else {
                if ((((trials[row]["question_num"] === trials[(row + 1)]["question_num"]) && (trials[row]["question_num"] === trials[(row + 2)]["question_num"])) && (trials[row]["question_num"] === trials[(row + 3)]["question_num"]))) {
                    conditionMet = false;
                    break;
                } else {
                    if ((((trials[row]["target_num"] === trials[(row + 1)]["target_num"]) && (trials[row]["target_num"] === trials[(row + 2)]["target_num"])) && (trials[row]["target_num"] === trials[(row + 3)]["target_num"]))) {
                        conditionMet = false;
                        break;
                    } else {
                        if ((((trials[row]["target_phoneme"] === trials[(row + 1)]["target_phoneme"]) && (trials[row]["target_phoneme"] === trials[(row + 2)]["target_phoneme"])) && (trials[row]["target_phoneme"] === trials[(row + 3)]["target_phoneme"]))) {
                            conditionMet = false;
                            break;
                        } else {
                            conditionMet = true;
                        }
                    }
                }
            }
        }
    }
    customOrder = [];
    for (var row, _pj_c = 0, _pj_a = util.range(trials.length), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
        row = _pj_a[_pj_c];
        customOrder.push(trials[row]["stim_order"]);
    }
    return customOrder;
}

This first led to an error as “data.importConditions()” is not supported by PsychoJS. Following Access Condition File variables online experiement - #2 by hellenjingyuan I edited:

trials = data.importConditions(excelFile);

to:

trials = excelFile;

However I now get this error:

TypeError: Cannot assign to read only property '18' of string 'List1_stim_data.csv'

I’m not familiar with JavaScript so I’m not sure where the issue is in the code (e.g., whether the indexing is wrong). Thanks in advance for the help!

2

Hi! I’m wondering what you mean when you say you get

TypeError: Cannot assign to read only property '18' of string 'List1_stim_data.csv'

as an error. It seems like the code somewhere is trying to do: 'List1_stim_data.csv'['18'] which doesn’t make sense because it’s a string.

Is data, in your trials = data.importConditions(excelFile); defined anywhere else in your javascript?

My guess is that is not – or that data is not the right kind of object.

myData = new TrialHandler({
psychoJS: psychoJS,
nReps: 1, method: TrialHandler.Method.SEQUENTIAL,
extraInfo: expInfo, originPath: undefined,
trialList: 'conditions.xlsx',
seed: undefined, name: 'myData'});
3

SOLUTION FOUND!

Thanks so much for your help! You’re right, I was making some mistakes when importing the conditions file. I went through some more debugging and I think I’ve actually managed to successfully translate the function to JS! I’m copying the working version here in case it’s useful to anyone:

shuffle = util.shuffle;
range = function (size, startAt = 0) {
    return [...Array(size).keys()].map(i => i + startAt);
}


pseudoRand = function(excelFile) {

    var conditionMet, conditions, customOrder, trials;
    
    trials = new TrialHandler({
    psychoJS: psychoJS,
    nReps: 1, method: TrialHandler.Method.SEQUENTIAL,
    extraInfo: expInfo, originPath: undefined,
    trialList: excelFile,
    seed: undefined, name: 'trials'});

    conditionMet = false;
    while ((conditionMet === false)) {
        shuffle(trials.trialList);
        conditions = [];
        for (var row, _pj_c = 0, _pj_a = range(trials.trialList.length), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
            row = _pj_a[_pj_c];
            conditions.push(trials.trialList[row]["stim_type"]);
        }
        for (var row, _pj_c = 0, _pj_a = range((trials.trialList.length - 3)), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
            row = _pj_a[_pj_c];
            if ((((trials.trialList[row]["stim_type"] === trials.trialList[(row + 1)]["stim_type"]) && (trials.trialList[row]["stim_type"] === trials.trialList[(row + 2)]["stim_type"])) && (trials.trialList[row]["stim_type"] === trials.trialList[(row + 3)]["stim_type"]))) {
                conditionMet = false;
                break;
            } else {
                if ((((trials.trialList[row]["question_num"] === trials.trialList[(row + 1)]["question_num"]) && (trials.trialList[row]["question_num"] === trials.trialList[(row + 2)]["question_num"])) && (trials.trialList[row]["question_num"] === trials.trialList[(row + 3)]["question_num"]))) {
                    conditionMet = false;
                    break;
                } else {
                    if ((((trials.trialList[row]["target_num"] === trials.trialList[(row + 1)]["target_num"]) && (trials.trialList[row]["target_num"] === trials.trialList[(row + 2)]["target_num"])) && (trials.trialList[row]["target_num"] === trials.trialList[(row + 3)]["target_num"]))) {
                        conditionMet = false;
                        break;
                    } else {
                        if ((((trials.trialList[row]["target_phoneme"] === trials.trialList[(row + 1)]["target_phoneme"]) && (trials.trialList[row]["target_phoneme"] === trials.trialList[(row + 2)]["target_phoneme"])) && (trials.trialList[row]["target_phoneme"] === trials.trialList[(row + 3)]["target_phoneme"]))) {
                            conditionMet = false;
                            break;
                        } else {
                            conditionMet = true;
                        }
                    }
                }
            }
        }
    }
    customOrder = [];
    for (var row, _pj_c = 0, _pj_a = range(trials.trialList.length), _pj_b = _pj_a.length; (_pj_c < _pj_b); _pj_c += 1) {
        row = _pj_a[_pj_c];
        customOrder.push(trials.trialList[row]["stim_order"]);
    }
    return customOrder;
}
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