gazeplotter/dist/class/Eye/EyeClassifier/EyeClassifier.js

Gazeplotter is a Svelte application for visualizing eye-tracking data.

export class EyeClassifier {
    classify(slice) {
        const type = this.getTypeFromSlice(slice);
        if (type === 'unknown')
            throw new Error('Unknown file type');
        const rowDelimiter = '\r\n';
        const columnDelimiter = this.getColumnDelimiter(type, slice);
        const headerRowId = type === 'ogama' ? 8 : 0;
        return {
            type,
            rowDelimiter,
            columnDelimiter,
            userInputSetting: '',
            headerRowId,
        };
    }
    getTypeFromSlice(slice) {
        if (this.isTobii(slice)) {
            if (slice.includes('Event'))
                return 'tobii-with-event';
            return 'tobii';
        }
        if (this.isGazePoint(slice))
            return 'gazepoint';
        if (this.isBeGaze(slice))
            return 'begaze';
        if (this.isOgama(slice))
            return 'ogama';
        if (this.isVarjo(slice))
            return 'varjo';
        if (this.isCsv(slice))
            return 'csv';
        if (this.isCsvSegmented(slice))
            return 'csv-segmented';
        return 'unknown';
    }
    getColumnDelimiter(type, slice) {
        switch (type) {
            case 'tobii':
            case 'tobii-with-event':
            case 'begaze':
            case 'ogama':
                return '\t';
            case 'gazepoint':
                return ',';
            case 'csv':
            case 'csv-segmented':
                return this.determineCsvDelimiter(slice);
            case 'varjo':
                return ';';
            default:
                throw new Error('Unknown file type');
        }
    }
    isTobii(slice) {
        return slice.includes('Recording timestamp');
    }
    isGazePoint(slice) {
        return slice.includes('FPOGS') && slice.includes('FPOGD');
    }
    isBeGaze(slice) {
        return (slice.includes('Event Start Trial Time [ms]') &&
            slice.includes('Event End Trial Time [ms]'));
    }
    isOgama(slice) {
        return slice.includes('# Contents: Similarity Measurements of scanpaths.');
    }
    isVarjo(slice) {
        return slice.includes('Time') && slice.includes('Actor Label');
    }
    isCsv(slice) {
        return (slice.includes('Time') &&
            slice.includes('Participant') &&
            slice.includes('Stimulus') &&
            slice.includes('AOI'));
    }
    isCsvSegmented(slice) {
        return (slice.includes('From') &&
            slice.includes('To') &&
            slice.includes('Participant') &&
            slice.includes('Stimulus') &&
            slice.includes('AOI'));
    }
    /**
     * To determine the delimiter used in a CSV file, we count the number of occurrences of the two most common delimiters
     * (',' and ';') in the header row. The delimiter with the higher count is used.
     *
     * @param slice - Text content of the first slice of the file, containing the header row
     * @returns delimiter used in the CSV file (either ',' or ';')
     */
    determineCsvDelimiter(slice) {
        const internationalDelimiter = ',';
        const germanDelimiter = ';';
        const headerOnly = slice.split('\r\n')[0];
        const internationalDelimiterCount = headerOnly.split(internationalDelimiter).length;
        const germanDelimiterCount = headerOnly.split(germanDelimiter).length;
        return internationalDelimiterCount > germanDelimiterCount
            ? internationalDelimiter
            : germanDelimiter;
    }
}