Blame view

node_modules/echarts/src/processor/dataSample.js 3.44 KB
aaac7fed   liuqimichale   add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
  /*
  * 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.
  */
  
  
  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, value) {
      return Math.round(frame.length / 2);
  };
  
  export default function (seriesType) {
      return {
  
          seriesType: seriesType,
  
          modifyOutputEnd: true,
  
          reset: function (seriesModel, ecModel, api) {
              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) {
                          // Only support sample the first dim mapped from value axis.
                          seriesModel.setData(data.downSample(
                              data.mapDimension(valueAxis.dim), 1 / rate, sampler, indexSampler
                          ));
                      }
                  }
              }
          }
      };
  }