function Single(axisModel, ecModel, api) {

	        /**
	         * @type {string}
	         * @readOnly
	         */
	        this.dimension = 'single';

	        /**
	         * Add it just for draw tooltip.
	         *
	         * @type {Array.<string>}
	         * @readOnly
	         */
	        this.dimensions = ['single'];

	        /**
	         * @private
	         * @type {module:echarts/coord/single/SingleAxis}.
	         */
	        this._axis = null;

	        /**
	         * @private
	         * @type {module:zrender/core/BoundingRect}
	         */
	        this._rect;

	        this._init(axisModel, ecModel, api);

	        /**
	         * @type {module:echarts/coord/single/AxisModel}
	         */
	        this.model = axisModel;
	    }
Convert the local coord(processed by dataToCoord())
to global coord(concrete pixel coord).
designated by module:echarts/coord/single/Single.
@type {Function}