逐步完成前后端服务器

frontend/node_modules/echarts/lib/processor/dataSample.js

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+
+/*
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*   http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing,
+* software distributed under the License is distributed on an
+* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+* KIND, either express or implied.  See the License for the
+* specific language governing permissions and limitations
+* under the License.
+*/
+
+
+/**
+ * AUTO-GENERATED FILE. DO NOT MODIFY.
+ */
+
+/*
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*   http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing,
+* software distributed under the License is distributed on an
+* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+* KIND, either express or implied.  See the License for the
+* specific language governing permissions and limitations
+* under the License.
+*/
+import { isFunction, isString } from 'zrender/lib/core/util.js';
+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]);
+    }
+    // NaN will cause illegal axis extent.
+    return isFinite(max) ? max : NaN;
+  },
+  min: function (frame) {
+    var min = Infinity;
+    for (var i = 0; i < frame.length; i++) {
+      frame[i] < min && (min = frame[i]);
+    }
+    // NaN will cause illegal axis extent.
+    return isFinite(min) ? min : NaN;
+  },
+  // TODO
+  // Median
+  nearest: function (frame) {
+    return frame[0];
+  }
+};
+var indexSampler = function (frame) {
+  return Math.round(frame.length / 2);
+};
+export default function dataSample(seriesType) {
+  return {
+    seriesType: seriesType,
+    // FIXME:TS never used, so comment it
+    // modifyOutputEnd: true,
+    reset: function (seriesModel, ecModel, api) {
+      var data = seriesModel.getData();
+      var sampling = seriesModel.get('sampling');
+      var coordSys = seriesModel.coordinateSystem;
+      var count = data.count();
+      // Only cartesian2d support down sampling. Disable it when there is few data.
+      if (count > 10 && coordSys.type === 'cartesian2d' && sampling) {
+        var baseAxis = coordSys.getBaseAxis();
+        var valueAxis = coordSys.getOtherAxis(baseAxis);
+        var extent = baseAxis.getExtent();
+        var dpr = api.getDevicePixelRatio();
+        // Coordinste system has been resized
+        var size = Math.abs(extent[1] - extent[0]) * (dpr || 1);
+        var rate = Math.round(count / size);
+        if (isFinite(rate) && rate > 1) {
+          if (sampling === 'lttb') {
+            seriesModel.setData(data.lttbDownSample(data.mapDimension(valueAxis.dim), 1 / rate));
+          } else if (sampling === 'minmax') {
+            seriesModel.setData(data.minmaxDownSample(data.mapDimension(valueAxis.dim), 1 / rate));
+          }
+          var sampler = void 0;
+          if (isString(sampling)) {
+            sampler = samplers[sampling];
+          } else if (isFunction(sampling)) {
+            sampler = sampling;
+          }
+          if (sampler) {
+            // Only support sample the first dim mapped from value axis.
+            seriesModel.setData(data.downSample(data.mapDimension(valueAxis.dim), 1 / rate, sampler, indexSampler));
+          }
+        }
+      }
+    }
+  };
+}