{
  "schema_version": 2,
  "id": "commands/tdigest.byrevrank",
  "title": "TDIGEST.BYREVRANK",
  "url": "https://redis.io/docs/latest/commands/tdigest.byrevrank/",
  "summary": "Returns, for each input reverse rank, an estimation of the floating-point value with that reverse rank",
  "since": "2.4.0",
  "tags": [
    "docs",
    "develop",
    "stack",
    "oss",
    "rs",
    "rc",
    "oss",
    "kubernetes",
    "clients"
  ],
  "last_updated": "2026-09-18T09:48:54+01:00",
  "page_type": "content",
  "content_hash": "d5e953b92a4ed2a81672a030aa66bca79bb3811d7f73bc57daa55cb7518ae6e2",
  "sections": [
    {
      "id": "overview",
      "title": "Overview",
      "role": "overview",
      "text": "Returns, for each input reverse rank (`revrank`), an estimation of the floating-point value with that reverse rank.\nMultiple estimations can be retrieved in a single call."
    },
    {
      "id": "required-arguments",
      "title": "Required arguments",
      "role": "content",
      "text": "<details open><summary><code>key</code></summary>\n\nis the key name of an existing t-digest sketch.\n</details>\n\n<details open><summary><code>revrank</code></summary>\n\nReverse ranks for which the values should be retrieved.\n\n0 is the reverse rank of the value of the largest observation.\n  \n_n_-1 is the reverse rank of the value of the smallest observation, where _n_ denotes the number of observations added to the sketch.\n</details>"
    },
    {
      "id": "examples",
      "title": "Examples",
      "role": "example",
      "text": "redis> TDIGEST.CREATE t COMPRESSION 1000\nOK\nredis> TDIGEST.ADD t 1 2 2 3 3 3 4 4 4 4 5 5 5 5 5\nOK\nredis> TDIGEST.BYREVRANK t 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15\n 1) \"5\"\n 2) \"5\"\n 3) \"5\"\n 4) \"5\"\n 5) \"5\"\n 6) \"4\"\n 7) \"4\"\n 8) \"4\"\n 9) \"4\"\n10) \"3\"\n11) \"3\"\n12) \"3\"\n13) \"2\"\n14) \"2\"\n15) \"1\"\n16) \"-inf\""
    },
    {
      "id": "redis-software-and-redis-cloud-compatibility",
      "title": "Redis Software and Redis Cloud compatibility",
      "role": "content",
      "text": "| Redis<br />Software | Redis<br />Cloud | <span style=\"min-width: 9em; display: table-cell\">Notes</span> |\n|:----------------------|:-----------------|:------|\n| <span title=\"Supported\">&#x2705; Supported</span><br /> | <span title=\"Supported\"><nobr>&#x2705; Flexible & Annual</nobr></span><br /><span title=\"Supported\">&#x2705; Free & Fixed</nobr></span> |  |"
    },
    {
      "id": "return-information",
      "title": "Return information",
      "role": "returns",
      "text": "**RESP2:**\n\nOne of the following:\n\n* [Array](https://redis.io/docs/latest/develop/reference/protocol-spec#arrays) of [bulk strings](https://redis.io/docs/latest/develop/reference/protocol-spec#bulk-strings) as floating-points, populated with value_1, value_2, ..., value_R:\n    * an accurate result when `rank` is `0`, the value of the largest observation.\n    * an accurate result when `rank` is _n_-1, the value of the smallest observation, where _n_ denotes the number of observations added to the sketch.\n    * `inf` when `rank` is equal to _n_ or larger than _n_.\n    * `nan` for all ranks when the given sketch is empty.\n* [Simple error reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-errors) in these cases: the given key does not exist or is of an incorrect type, rank parsing errors, or an incorrect number of arguments.\n\n**RESP3:**\n\nOne of the following:\n\n* [Array](https://redis.io/docs/latest/develop/reference/protocol-spec#arrays) of [doubles](https://redis.io/docs/latest/develop/reference/protocol-spec#doubles) as floating-points, populated with value_1, value_2, ..., value_R:\n    * an accurate result when `rank` is `0`, the value of the largest observation.\n    * an accurate result when `rank` is _n_-1, the value of the smallest observation, where _n_ denotes the number of observations added to the sketch.\n    * `inf` when `rank` is equal to _n_ or larger than _n_.\n    * `nan` for all ranks when the given sketch is empty.\n* [Simple error reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-errors) in these cases: the given key does not exist or is of an incorrect type, rank parsing errors, or an incorrect number of arguments."
    }
  ],
  "examples": []
}