# How to calculate gauss value

I want to know how this gauss value is calculated.

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

query result

`````` "_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" : [ ]
}
]
},

``````

Referring to this Function score query doc

where is computed to assure that the score takes the value `decay` at distance `scale` from `origin` +- `offset`

I want to know how this standard deviation value is calculated.

"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)",

How this `28853.900817779268` value is calculated

Hi, this is the direct application of the formula for sigma-square:
decay is 0.5 (by default)