function get() {
	/* eslint-disable no-invalid-this */
	var scale = this.xScale;
	return xPos;

	/**
	* Maps a value to a x coordinate value.
	*
	* @private
	* @param {Array} d - datum
	* @returns {number} pixel value
	*/
	function xPos( d ) {
		var px = scale( d[0] );
		debug( 'Value: %d => Pixel: %d.', d[0], px );
		return px;
	}
}
Returns a function to map values to x coordinate values.

@private
@returns {Function} map function