R/508-acc.R
acc.Rd
Auto Cross Covariance (ACC) for Generating Scales-Based Descriptors of the Same Length
acc(mat, lag)
mat | A |
---|---|
lag | The lag parameter. Must be less than the amino acids. |
A length lag * p^2
named vector, the element names are
constructed by: the scales index (crossed scales index) and
lag index.
This function calculates the auto covariance and auto cross covariance for generating scale-based descriptors of the same length.
To know more details about auto cross covariance, see the references.
Wold, S., Jonsson, J., Sj\"orstr\"om, M., Sandberg, M., & R\"annar, S. (1993). DNA and peptide sequences and chemical processes multivariately modelled by principal component analysis and partial least-squares projections to latent structures. Analytica chimica acta, 277(2), 239--253.
Sj\"ostr\"om, M., R\"annar, S., & Wieslander, A. (1995). Polypeptide sequence property relationships in Escherichia coli based on auto cross covariances. Chemometrics and intelligent laboratory systems, 29(2), 295--305.
See extractPCMScales
for
generalized scales-based descriptors.
For more details, see extractPCMDescScales
and extractPCMPropScales
.
# NOT RUN { p = 8 # p is the scales number n = 200 # n is the amino acid number lag = 7 # the lag paramter mat = matrix(rnorm(p * n), nrow = p, ncol = n) acc(mat, lag) # }