docs: add description for fieldNormWeight

Fixes #603
krisk · Dec 23, 2021 · 36bada4 · 36bada4
1 parent af78b2e
commit 36bada4
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Showing 3 changed files with 21 additions and 4 deletions.
diff --git a/docs/api/options.md b/docs/api/options.md
@@ -131,4 +131,11 @@ When `true`, the calculation for the relevance score (used for sorting) will ign
 The only time it makes sense to set `ignoreFieldNorm` to `true` is when it does not matter how many terms there are, but only that the query term exists.
 :::
 
+### `fieldNormWeight`
+
+- Type: `number`
+- Default: `1`
+
+Determines how much the [field-length norm](/concepts/scoring-theory.html#field-length-norm) affects scoring. A value of `0` is equivalent to ignoring the field-length norm. A value of `0.5` will greatly reduce the effect of field-length norm, while a value of `2.0` will greatly increase it.
+
 <Donate />
diff --git a/docs/concepts/scoring-theory.md b/docs/concepts/scoring-theory.md
@@ -37,7 +37,7 @@ User inputted weight of the key. The higher the weight, the higher its relevance
 The shorter the field, the higher its relevance. If a pattern matches a short field (such as a `title` field) it is likely to be more relevant than the same pattern matched with a bigger field. This is calculated at index time.
 
 ::: tip
-You can ignore the field-length norm by setting `ignoreFieldNorm` to `true`.
+You can ignore the field-length norm by setting `ignoreFieldNorm` to `true`. Alternatively, you can configure how much the field-length norm affects your scoring by setting `fieldNormWeight` to a value other than 1 (the default).
 :::
 
 <Donate />
diff --git a/src/tools/FuseIndex.js b/src/tools/FuseIndex.js
@@ -4,7 +4,10 @@ import normGenerator from './norm'
 import { createKey } from './KeyStore'
 
 export default class FuseIndex {
-  constructor({ getFn = Config.getFn, fieldNormWeight = Config.fieldNormWeight } = {}) {
+  constructor({
+    getFn = Config.getFn,
+    fieldNormWeight = Config.fieldNormWeight
+  } = {}) {
     this.norm = normGenerator(fieldNormWeight, 3)
     this.getFn = getFn
     this.isCreated = false
@@ -147,15 +150,22 @@ export default class FuseIndex {
   }
 }
 
-export function createIndex(keys, docs, { getFn = Config.getFn, fieldNormWeight = Config.fieldNormWeight } = {}) {
+export function createIndex(
+  keys,
+  docs,
+  { getFn = Config.getFn, fieldNormWeight = Config.fieldNormWeight } = {}
+) {
   const myIndex = new FuseIndex({ getFn, fieldNormWeight })
   myIndex.setKeys(keys.map(createKey))
   myIndex.setSources(docs)
   myIndex.create()
   return myIndex
 }
 
-export function parseIndex(data, { getFn = Config.getFn, fieldNormWeight = Config.fieldNormWeight } = {}) {
+export function parseIndex(
+  data,
+  { getFn = Config.getFn, fieldNormWeight = Config.fieldNormWeight } = {}
+) {
   const { keys, records } = data
   const myIndex = new FuseIndex({ getFn, fieldNormWeight })
   myIndex.setKeys(keys)