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Defining partially observed bidimensional functional data terms in VDPO formulae

ffpo_2d.Rd

Auxiliary function used to define ffpo_2d terms within VDPO model formulae.

Usage

ffpo_2d(X, miss_points, missing_points, nbasis = rep(15, 4), bdeg = rep(3, 4))

Arguments

X

partially observed bidimensional functional covariate matrix.

miss_points, missing_points

list of missing observation points. See 'Details' for more information about the difference in structure between both.

nbasis

number of basis to be used.

bdeg

degree of the basis to be used.

Value

The function is interpreted in the formula of a VDPO model. list containing the following elements:

  • B_ffpo2d design matrix.

  • Phi_ffpo2d bidimensional B-spline basis used for the functional coefficient.

  • M_ffpo2d the missing_points used as input in the function.

  • nbasis number of the basis used.

Details

The difference between miss_points and missing_points is the format in which the data is presented.

miss_points is a list of lists where each inner list corresponds to the observation points in the y-axis and contains the observation points of the missing values for the x-axis. miss_points acts as a guide for identifying and addressing missing observations in functional data and is used for properly calculating the inner product matrix.

missing_points is a list where each element is a matrix containing the missing observations points.