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