circular citation area radius
The circular citation area radius (Sangwal 2012) is an easy to calculate approximation of the h-index.
$$r=\sqrt{\frac{C^P}{\pi}}=\sqrt{\frac{\sum\limits_{i=1}^{P}{C_i}}{\pi}}$$History
| Year | r |
|---|---|
| 1997 | 0.7979 |
| 1998 | 2.2568 |
| 1999 | 3.7424 |
| 2000 | 5.2016 |
| 2001 | 6.8637 |
| 2002 | 9.0622 |
| 2003 | 11.2697 |
| 2004 | 14.2618 |
| 2005 | 17.3161 |
| 2006 | 20.7373 |
| 2007 | 23.8633 |
| 2008 | 26.7738 |
| 2009 | 29.5594 |
| 2010 | 32.6695 |
| 2011 | 35.9314 |
| 2012 | 38.8718 |
| 2013 | 41.8984 |
| 2014 | 44.5317 |
| 2015 | 47.0414 |
| 2016 | 49.4399 |
| 2017 | 51.4960 |
| 2018 | 53.5178 |
| 2019 | 55.4745 |
| 2020 | 57.3978 |
| 2021 | 59.3848 |
| 2022 | 61.2633 |
| 2023 | 62.8837 |
| 2024 | 64.4931 |
| 2025 | 65.3486 |
References
- Sangwal, K. (2012) On the relationship between citations of publication output and Hirsch index h of authors: Conceptualization of tapered Hirsch index hT, circular citation area radius R and ciation acceleration a. Scientometrics 93:987–1004.