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 | 2.1851 |
| 1999 | 3.7424 |
| 2000 | 5.1709 |
| 2001 | 6.7937 |
| 2002 | 9.0270 |
| 2003 | 11.2697 |
| 2004 | 14.2841 |
| 2005 | 17.3528 |
| 2006 | 20.7986 |
| 2007 | 23.9099 |
| 2008 | 26.8094 |
| 2009 | 29.6025 |
| 2010 | 32.6841 |
| 2011 | 35.9668 |
| 2012 | 38.9454 |
| 2013 | 41.9516 |
| 2014 | 44.5531 |
| 2015 | 47.0617 |
| 2016 | 49.4721 |
| 2017 | 51.5331 |
| 2018 | 53.5683 |
| 2019 | 55.5118 |
| 2020 | 57.4117 |
| 2021 | 59.4357 |
| 2022 | 61.3334 |
| 2023 | 62.9470 |
| 2024 | 64.6065 |
| 2025 | 64.9921 |
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.