# R hat of 1.01

**URL:** <https://discourse.mc-stan.org/t/r-hat-of-1-01/23145>\
**Category:** General\
**Created:** [June 23, 2021, 6:06am UTC](https://discourse.mc-stan.org/t/r-hat-of-1-01/23145 "2021-06-23T06:06:23Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Rehab](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@Rehab](https://discourse.mc-stan.org/u/Rehab)\
**Post date:** [June 23, 2021, 6:06am UTC](https://discourse.mc-stan.org/t/r-hat-of-1-01/23145/1 "2021-06-23T06:06:23Z")

</div>

Hello everyone

I came across a recent study entitled Rank-normalization, folding, and localization: An improved R hat for assessing convergence of MCMC, by Vehtari, Gelman, Simpson, Bob Carpenter, and Bürkner (2020).

What I understand, that it is recommended to use R hat of 1.01 in order to ensure chain convergence instead of the previous recommended value of 1.10 suggested by Gelman and Rubin (1992).

My question is, will this new value also be applied to the traditional computation of R hat? Because as far as I understand, the new value of 1.01 is associated with the new calculation of R hat that is based on rank normalizing.  
Is this new version of R hat incorporated in R program?

Thank you, and I am sorry if I misunderstand any part of this paper.  
Rehab

---

<div class="post-metadata">

**Author:** ![jonah](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/jonah/32/200_2.png) [@jonah](https://discourse.mc-stan.org/u/jonah)\
**Post date:** [June 23, 2021, 10:34pm UTC](https://discourse.mc-stan.org/t/r-hat-of-1-01/23145/2 "2021-06-23T22:34:33Z")

</div>

> [@Rehab](#):
>
> Is this new version of R hat incorporated in R program?

Yeah it’s available in our new package **posterior** :

> **[Tools for Working with Posterior Distributions](https://mc-stan.org/posterior/index.html)**
>
> Provides useful tools for both users and developers of packages 
> for fitting Bayesian models or working with output from Bayesian models. 
> The primary goals of the package are to: 
> (a) Efficiently convert between many different useful formats...

It’s not on CRAN quite yet but you can install it from github:

```r
remotes::install_github("stan-dev/posterior")

```

The new r-hat is computed by the `rhat()` function. The old version of r-hat is available via `rhat_basic()`.

---

<div class="post-metadata">

**Author:** ![Rehab](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@Rehab](https://discourse.mc-stan.org/u/Rehab)\
**Post date:** [June 24, 2021, 6:24am UTC](https://discourse.mc-stan.org/t/r-hat-of-1-01/23145/3 "2021-06-24T06:24:53Z")

</div>

Many thanks, Johan, for sharing this information.  
It helps a lot.