# plot_direction_Aopt: Verify the optimality condition for the A-optimal design In SLSEdesign: Optimal Regression Design under the Second-Order Least Squares Estimator

 plot_direction_Aopt R Documentation

## Verify the optimality condition for the A-optimal design

### Description

Verify the optimality condition for the A-optimal design

### Usage

``````plot_direction_Aopt(u, design, tt, FUN, theta)
``````

### Arguments

 `u` The discretized design points. `design` The A-optimal design that contains the design points and the associated weights `tt` The level of skewness. `FUN` The function to calculate the derivative of the given model. `theta` The parameter value of the model.

### Details

This function produces the figure for the directional derivative of the given A-optimal design of the compact supports. According to the general equivalence theorem, for an optimal design, all the negative value of the directional derivative should be below zero line.

### Value

The plot of the negative value of the directional derivative of an A-optimal design

### Examples

``````poly3 <- function(xi, theta){
matrix(c(1, xi, xi^2, xi^3), ncol = 1)
}
design = data.frame(location = c(-1, -0.464, 0.464, 1),
weight = c(0.151, 0.349, 0.349, 0.151))
u = seq(-1, 1, length.out = 201)
plot_direction_Aopt(u=u, design=design, tt=0, FUN = poly3, theta = rep(0,4))

``````

SLSEdesign documentation built on June 22, 2024, 9:45 a.m.