Table 3 Correlation and regression expression between shape parameters values and the Krumbein’s visual images
From: New parameter of roundness R: circularity corrected by aspect ratio
Shape parameters | Correlation coefficient | Regression expressions | References | |||
|---|---|---|---|---|---|---|
Individual valuesa (n = 81) | Adjusted coefficient of determination of individual values (n = 81) | Mean values (n = 9) | Adjusted coefficient of determination of mean values (n = 9) | |||
D | – | – | 0.778b | 0.549b | D = 1.0541 − 0.0335·R K | Vallejo and Zhou (1995) |
R K = 19.255 − 18.079·D c | ||||||
Mi | 0.940 | – | – | – | Mi = 28.38 − 46.18 R K + 21.71 R K 2 | Itabashi et al. (2004) |
FD | 0.939 | – | – | – | FD = 1.03655 − 0.05799·R K + 0.02698·R K 2 | Itabashi et al. (2004) |
FU d | 0.857 | – | – | – | FU = 0.0736 + 0.264·R K | Itabashi et al. (2004) |
rW | 0.919 | – | 0.992 | – | Roussillon et al. (2009) | |
R | 0.937 | 0.874 | 0.995 | 0.987 | R K = 6.9940 − 20.575·R + 15.349·R 2 | This study |