define(function (require) {
    'use strict';
    var zrUtil = require('zrender/core/util');
    var Axis = require('../Axis');
    function RadiusAxis(scale, radiusExtent) {
        Axis.call(this, 'radius', scale, radiusExtent);
        /**
         * Axis type
         *  - 'category'
         *  - 'value'
         *  - 'time'
         *  - 'log'
         * @type {string}
         */
        this.type = 'category';
    }
    RadiusAxis.prototype = {
        constructor: RadiusAxis,
        dataToRadius: Axis.prototype.dataToCoord,
        radiusToData: Axis.prototype.coordToData
    };
    zrUtil.inherits(RadiusAxis, Axis);
    return RadiusAxis;
}); 
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