When implementing an Anhui province map in ECharts, the built-in version contained outdated administrative boundaries including Chaohu City, which was no longer acceptable. The ECharts Map Data Tool (http://ecomfe.github.io/echarts-map-tool/) provided updated GeoJSON data for Anhui province.

Initial attempts using the extension map functionality encountered issues with the echart.util module. After consulting the API documentation, the correct approach was identifeid:

require('echarts/util/mapData/params').params.anhui = {
    getGeoJson: function (callback) {
        $.getJSON('geoJson/anhui.json', function (data) {
            callback(require('echarts/util/mapData/params').decode(data));
        });
    }
};

The key discovery was that compressed map data requires proper decoding. The correct method chain is require('echarts/util/mapData/params').decode(data) rather than require('echarts/util/mapData/params').params.decode(data).

For enhanced functionality, mouse hover events can be implemented:

var chartConfig = require('echarts/config');
chartInstance.on(chartConfig.EVENT.HOVER, function (eventParams) {
    var cityName = eventParams.name;
    displayCityInfo(cityName);
});

Custom tooltip formatters allow displaying multiple data points:

var schoolData = [
    { name: 'Hefei', value: 15 },
    { name: 'Wuhu', value: 12 },
    { name: 'Bengbu', value: 8 }
];

var programData = [
    { name: 'Hefei', value: 25 },
    { name: 'Wuhu', value: 18 },
    { name: 'Bengbu', value: 14 }
];

var chartOptions = {
    tooltip: {
        trigger: 'item',
        formatter: function (params) {
            var tooltipContent = params.name + '<br/>Total: ' + params.value + ' projects';
            
            for (var i = 0; i < schoolData.length; i++) {
                if (params.name === schoolData[i].name) {
                    tooltipContent += '<br/>Schools: ' + schoolData[i].value;
                }
                if (params.name === programData[i].name) {
                    tooltipContent += '<br/>Programs: ' + programData[i].value;
                }
            }
            return tooltipContent;
        }
    },
    series: [{
        type: 'map',
        mapType: 'anhui',
        data: [
            { name: 'Hefei', value: Math.floor(Math.random() * 100) },
            { name: 'Wuhu', value: Math.floor(Math.random() * 100) },
            { name: 'Bengbu', value: Math.floor(Math.random() * 100) }
        ]
    }]
};

The complete implementation ensures the updated Anhui province boundaries are displayed correctly, excluding the deprecated Chaohu City region.