# CMS.INITBYPROB












Initializes a Count-Min Sketch to accommodate requested tolerances.

### Parameters:

* **key**: The name of the sketch.
* **error**: Estimate size of error. The error is a percent of total counted
    items. This effects the width of the sketch.
* **probability**: The desired probability for inflated count. This should
    be a decimal value between 0 and 1. This effects the depth of the sketch.
    For example, for a desired false positive rate of 0.1% (1 in 1000),
    error_rate should be set to 0.001. The closer this number is to zero, the
    greater the memory consumption per item and the more CPU usage per operation.

## Examples

```
redis> CMS.INITBYPROB test 0.001 0.01
OK
```

## Return information

{{< multitabs id=“cms-initbyprob-return-info" 
    tab1="RESP2" 
    tab2="RESP3" >}}

One of the following:

* [Simple string reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-strings) `OK` if executed correctly.
* [Simple error reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-errors) if the given key already exists.

-tab-sep-

One of the following:

* [Simple string reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-strings) `OK` if executed correctly.
* [Simple error reply](https://redis.io/docs/latest/develop/reference/protocol-spec#simple-errors) if the given key already exists.