Select the number of significant principal components of a matrix via adjust correlation threshold (ACT)
eigengap.act(covmat, nobs, maxcomp = NULL)
matrix to be decomposed
number of observations used to compute the covariance matrix
maximum number of eigenvalues to compute
Fan, J., Guo, j. and Zheng, S. (2020). Estimating number of factors by adjusted eigenvalues thresholding. Journal of the American Statistical Association, 117(538): 852--861