如何计算高斯值？

Question

我只是想知道我应用公式时这个值是怎么来的，但我想我遗漏了什么有人能告诉我 please.I 是运行单个 ELK 堆栈版本 7.16

POST sneaker/_search
{
  "query": {
    "function_score": {
      "functions": [
        {
          "gauss": {
            "price": {
              "origin": "300",
              "scale": "200"
            }
          }
        }
      ]
    }
  }
  , "explain": true
}

查询结果

 "max_score" : 1.0,
    "hits" : [
      {
        "_shard" : "[sneaker][0]",
        "_node" : "29ds_f0VSM6_-eDNhdQPLw",
        "_index" : "sneaker",
        "_type" : "_doc",
        "_id" : "6",
        "_score" : 1.0,
        "_source" : {
          "brand" : "flite",
          "price" : 300,
          "rating" : 2,
          "release_date" : "2020-12-21"
        },
        "_explanation" : {
          "value" : 1.0,
          "description" : "function score, product of:",
          "details" : [
            {
              "value" : 1.0,
              "description" : "*:*",
              "details" : [ ]
            },
            {
              "value" : 1.0,
              "description" : "min of:",
              "details" : [
                {
                  "value" : 1.0,
                  "description" : "Function for field price:",
                  "details" : [
                    {
                      "value" : 1.0,
                      "description" : "exp(-0.5*pow(MIN[Math.max(Math.abs(300.0(=doc value) - 300.0(=origin))) - 0.0(=offset), 0)],2.0)/28853.900817779268)",
                      "details" : [ ]
                    }
                  ]
                },

我寻找高斯分布，但它与此不同。我想知道28853.900817779268值是怎么来的

Answer 1

如果您查看 gauss decay function 的官方文档，您会发现以下用于计算 sigma 的公式：

使用 scale = 200 和 decay = 0.5（如果未指定则为默认值），我们得到以下结果：

-200^2 / (2 * ln (0.5)) = -28853.90081

这就是您在查询解释中看到的内容。

如何计算高斯值？

How to calculate gauss value?

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