ACEt (version 1.3)

AtCtEp: The ACE(t)-p model

Description

The ACE(t)-p model with the A and C variance components as functions with respect to age modelled by P-splines.

Usage

AtCtEp(data_m, data_d, knot_a = 8, knot_c = 8, eps = 0.1)

Arguments

data_m

An $N_m$ x 3 data matrix for MZ twins. $N_m$ is the number of MZ twin pairs. The first two columns are traits and the third column is age (or other covariates).

data_d

An $N_d$ x 3 data matrix for DZ twins. $N_d$ is the number of DZ twin pairs. The first two columns are traits and the third column is age (or other covariates).

knot_a

The number of interior knots for the A component. The default value is 8.

knot_c

The number of interior knots for the C component. The default value is 8.

eps

Tolerance for convergence of the EM algorithm iterations. The default value is 0.1.

Value

• var
  The estimated variance of the E component.
• var_b_a
  The estimated variance for the penalized coefficient for the A components.
• var_b_c
  The estimated variance for the penalized coefficient for the C components.
• beta_c
  The estimated spline coefficients of the A component.
• beta_a
  The estimated spline coefficients of the C component.
• con
  The indicator of convergence of the optimization algorithm.
• lik
  The minus log marginal likelihood.
• knot_a
  The values of the knots for the A component.
• knot_c
  The values of the knots for the C component.

References

Liang He, Mikko J. Sillanp��, Karri Silventoinen, Jaakko Kaprio, Janne Pitk�niemi, Estimating modifying effect of age on genetic and environmental variance components in twin models. Genetics, 2016

Examples

# data(data_ace)

# result <- AtCtEp(data_ace$mz, data_ace$dz, knot_a = 8, knot_c = 8)