META-INF.assets.rjzjh.echarts.src.processor.dataSample.js Maven / Gradle / Ivy
define(function () {
var samplers = {
average: function (frame) {
var sum = 0;
var count = 0;
for (var i = 0; i < frame.length; i++) {
if (!isNaN(frame[i])) {
sum += frame[i];
count++;
}
}
// Return NaN if count is 0
return count === 0 ? NaN : sum / count;
},
sum: function (frame) {
var sum = 0;
for (var i = 0; i < frame.length; i++) {
// Ignore NaN
sum += frame[i] || 0;
}
return sum;
},
max: function (frame) {
var max = -Infinity;
for (var i = 0; i < frame.length; i++) {
frame[i] > max && (max = frame[i]);
}
return max;
},
min: function (frame) {
var min = Infinity;
for (var i = 0; i < frame.length; i++) {
frame[i] < min && (min = frame[i]);
}
return min;
},
// TODO
// Median
nearest: function (frame) {
return frame[0];
}
};
var indexSampler = function (frame, value) {
return Math.round(frame.length / 2);
};
return function (seriesType, ecModel, api) {
ecModel.eachSeriesByType(seriesType, function (seriesModel) {
var data = seriesModel.getData();
var sampling = seriesModel.get('sampling');
var coordSys = seriesModel.coordinateSystem;
// Only cartesian2d support down sampling
if (coordSys.type === 'cartesian2d' && sampling) {
var baseAxis = coordSys.getBaseAxis();
var valueAxis = coordSys.getOtherAxis(baseAxis);
var extent = baseAxis.getExtent();
// Coordinste system has been resized
var size = extent[1] - extent[0];
var rate = Math.round(data.count() / size);
if (rate > 1) {
var sampler;
if (typeof sampling === 'string') {
sampler = samplers[sampling];
}
else if (typeof sampling === 'function') {
sampler = sampling;
}
if (sampler) {
data = data.downSample(
valueAxis.dim, 1 / rate, sampler, indexSampler
);
seriesModel.setData(data);
}
}
}
}, this);
};
});