6.6 KiB
jsPsych.data
The jsPsych.data module contains functions for interacting with the data generated by jsPsych plugins.
jsPsych.data.dataAsCSV
jsPsych.data.dataAsCSV(append_data)
Parameters
| Parameter | Type | Description |
|---|---|---|
| append_data | object | Object of key: value pairs. Each key will become a column in the CSV file, whose rows are all filled in with the specified value. |
Return value
Returns a string in CSV format
Description
Generate a CSV formatted string containing all of the data generated in the experiment.
Examples
Basic example
var csvString = jsPsych.data.dataAsCSV();
Appending a column with a subject ID
var subjectID = 14;
var csvString = jsPsych.data.dataAsCSV({subject: subjectID});
jsPsych.data.displayData
jsPsych.data.displayData(format)
Parameters
| Parameter | Type | Description |
|---|---|---|
| format | string | Specifies whether to display the data in 'csv' or 'json' format. |
Return value
Returns nothing.
Description
Outputs all of the data collected in the experiment to the screen in either JSON or CSV format. This is a useful method for quick debugging when developing an experiment.
Examples
Using the on_finish callback function to show data at the end of the experiment
jsPsych.init({
experiment_structure: exp,
on_finish: function() {
jsPsych.data.displayData('csv');
}
})
jsPsych.data.getData
jsPsych.data.getData()
Parameters
None.
Return value
Returns an array containing all of the data generated in the experiment. Each element of the array contains the data for a single trial. Each trial's data is stored as an object in key: value format.
Description
Gets all of the data generated by the experiment.
Example
var alldata = jsPsych.data.getData();
jsPsych.data.getLastChunkData
jsPsych.data.getLastChunkData()
Parameters
None.
Return value
Returns an array containing all of the data generated in the same chunk as the last trial. Each element of the array contains the data for a single trial. Each trial's data is stored as an object in key: value format.
Description
Gets all of the data generated in the same chunk as the last trial.
Example
var lastchunkdata = jsPsych.data.getLastChunkData();
jsPsych.data.getLastTrialData
jsPsych.data.getLastTrialData()
Parameters
None.
Return value
Returns an object in key: value format containing the data from the last trial.
Description
Gets the data generated by the last trial.
Example
var lasttrialdata = jsPsych.data.getLastTrialData();
jsPsych.data.getTrialsFromChunk
jsPsych.data.getTrialsFromChunk(chunk_id)
Parameters
| Parameter | Type | Description |
|---|---|---|
| chunk_id | string | The id of the chunk to get data from. |
Return value
Returns an array containing all of the data generated in a specified chunk. Each element of the array contains the data for a single trial. Each trial's data is stored as an object in key: value format.
Description
Get all the data generated by a specified chunk.
Example
var current_chunk_id = jsPsych.currentChunkID();
var data_from_current_chunk = jsPsych.data.getTrialsFromChunk(current_chunk_id);
jsPsych.data.getTrialsOfType
jsPsych.data.getTrialsOfType(type)
Parameters
| Parameter | Type | Description |
|---|---|---|
| type | string | Which plugin to get trial data from. |
Return value
Returns an array containing all of the data generated by a particular plugin. Each element of the array contains the data for a single trial. Each trial's data is stored as an object in key: value format.
Description
Gets all the data generated by trials from a particular plugin.
Examples
Basic example
var all_xab_trials = jsPsych.data.getTrialsOfType('xab');
Compute average RT over whole experiment
// this example shows how this method could be used to display data
// to the subject, by finding all trials of type 'single-stim' and
// calculating the average response time.
var debrief_block = {
type: "text",
text: function() {
return "<p>Your average response time was <strong>" +
getAverageResponseTime() + "ms</strong>. Press " +
"any key to complete the experiment. Thank you!</p>";
}
};
function getAverageResponseTime() {
var trials = jsPsych.data.getTrialsOfType('single-stim');
var sum_rt = 0;
var valid_trial_count = 0;
for (var i = 0; i < trials.length; i++) {
if (trials[i].rt > -1) {
sum_rt += trials[i].rt;
valid_trial_count++;
}
}
return Math.floor(sum_rt / valid_trial_count);
}
jsPsych.data.localSave
jsPsych.data.localSave(filename, format, append_data)
Parameters
| Parameter | Type | Description |
|---|---|---|
| filename | string | Filename of locally saved file |
| format | string | Specifies either 'csv' or 'json' format |
| append_data | object | Object of key: value pairs. Each key will become a column in the CSV file (or property of each trial object if saving in JSON format), whose rows are all filled in with the specified value. |
Return value
Returns nothing.
Description
Saves a CSV or JSON file on the computer running the experiment. If conducting an online experiment, this will download the file onto the subject's computer, and is therefore not a recommended data storage solution for online data collection.
Warning: This function relies on features which are currently not supported by all major web browsers, though adoption rates are increasing rapidly. It will work on the most recent versions of Chrome, Firefox, Safari, and Internet Explorer.
Example
jsPsych.data.localSave('mydata.csv', 'csv', {subject: 12});
jsPsych.data.write
jsPsych.data.write(data_object)
Parameters
| Parameter | Type | Description |
|---|---|---|
| data_object | object | Object of key: value pairs to store in jsPsych's data storage. |
Return value
Returns nothing.
Description
This is the only method available for storing data in jsPsych's data container. All plugins that write data do so using this method. It is not intended to be used outside of a plugin.
Examples
var trial_data = {
correct: true,
rt: 487
}
jsPsych.data.write(trial_data);