T2_stat: Hotelling T2-statistic for layer boundary determination

In maxgav13/GMisc: Miscellaneous Functions for Geology (and its areas)

Hotelling T2-statistic for layer boundary determination

Description

Calculates the T2-statistic and corresponding effect size (Mahalanobis distance) for a perforation log with more than 1 variable. The coefficient is used to find layer boundaries in a perforation log.

Usage

T2_stat(data, k = 50)

Arguments

data	A data frame containing the depth of perforation in the first column, and the variables of interest in the rest of the columns, for a CPTu test: point resistance (qc), sleeve friction (fs), and pore-water pressure (u)
k	The window length for the number of data points to include in the calculation of T2-statistic. Always and even (par) number. Larger values make the resulting statistic smoother

Details

The example data given is intended to show the structure needed for input data. The user should follow this structure, which in general corresponds with a data frame with a sequence in the first column and the observed/measured values in the second, third, and fourth columns

Value

ggplot and plotly objects showing the Mahalanobis D2 statistic and lines marking the critical values at 0.95, 0.99, and 0.999, and suggested boundaries

References

Davis, J. C. (2002). Statistical and Data Analysis in Geology. 3rd ed. John Wiley & Sons.

Examples

T2_stat(CPTu_data, k = 50)

maxgav13/GMisc documentation built on June 12, 2022, 3:48 a.m.