# File Name: demo_Section4_T.r
# Description:
# The codes for the implementation of Section 4, the case of five toxicology
# models with Gaussian errors. We shown in this case how to use the PSO-QN
# algorithm to find the T-optimal designs for each pair discrimination.
# Then, we use the PSO-S-QN algorithm to find the max-min T-optimal design
# for discriminating among all five models.
# Reference:
# ----------------------------------------------------------------------------
# Load packages
library(DiscrimOD); library(Rcpp)
# ----------------------------------------------------------------------------
# 1. Create competing models using C++ codes (faster)
# ----------------------------------------------------------------------------
tox5 <- cppFunction('
Rcpp::NumericVector tox5(Rcpp::NumericMatrix x, Rcpp::NumericVector p) {
Rcpp::NumericVector eta(x.nrow());
for (int i = 0; i < x.nrow(); i++) {
eta(i) = p(0)*(p(2) - (p(2) - 1.0)*std::exp((-1.0)*std::pow(x(i,0)/p(1), p(3)))); }
return eta;
}')
tox4 <- cppFunction('
Rcpp::NumericVector tox4(Rcpp::NumericMatrix x, Rcpp::NumericVector p) {
Rcpp::NumericVector eta(x.nrow());
for (int i = 0; i < x.nrow(); i++) {
eta(i) = p(0)*(p(2) - (p(2) - 1.0)*std::exp((-1.0)*x(i,0)/p(1))); }
return eta;
}')
tox3 <- cppFunction('
Rcpp::NumericVector tox3(Rcpp::NumericMatrix x, Rcpp::NumericVector p) {
Rcpp::NumericVector eta(x.nrow());
for (int i = 0; i < x.nrow(); i++) {
eta(i) = p(0)*std::exp((-1.0)*std::pow(x(i,0)/p(1), p(2))); }
return eta;
}')
tox2 <- cppFunction('
Rcpp::NumericVector tox2(Rcpp::NumericMatrix x, Rcpp::NumericVector p) {
Rcpp::NumericVector eta(x.nrow());
for (int i = 0; i < x.nrow(); i++) {
eta(i) = p(0)*std::exp((-1.0)*x(i,0)/p(1)); }
return eta;
}')
tox1 <- cppFunction('
Rcpp::NumericVector tox1(Rcpp::NumericMatrix x, Rcpp::NumericVector p) {
Rcpp::NumericVector eta(x.nrow());
for (int i = 0; i < x.nrow(); i++) { eta(i) = p(0); }
return eta;
}')
# Or, create competing models using R codes
#tox5 <- function(x, p) p[1]*(p[3] - (p[3] - 1)*exp(-(x/p[2])^p[4]))
#tox4 <- function(x, p) p[1]*(p[3] - (p[3] - 1)*exp(-(x/p[2])))
#tox3 <- function(x, p) p[1]*exp(-(x/p[2])^p[3])
#tox2 <- function(x, p) p[1]*exp(-(x/p[2]))
#tox1 <- function(x, p) rep(p[1], length(x))
# ----------------------------------------------------------------------------
# 2. Set the discrimination design problem
# ----------------------------------------------------------------------------
# The true model is 'linlogi4' and we set the nominal values
para_tox_5 <- c(4.282, 835.571, 0.739, 3.515)
# Create a model list as the input of our PSO-QN algorithm
model_tox <- list(
# The fitst object should always be the true model
# Input the model function to the label 'model'
# Input the nominal values to the labal 'para'
list(model = tox5, para = para_tox_5),
# Starting from the second object, specify the rival models
# Input the model function to the label 'model'
# Input the lower and upper bounds for the rival parameters to the labal
# 'paraLower' and 'paraUpper' (based on experiences)
list(model = tox4, paraLower = c(0, 0, 0), paraUpper = c(20, 5000, 1)),
# The third model
list(model = tox3, paraLower = c(0, 0, 1), paraUpper = c(20, 5000, 15)),
# The fourth model
list(model = tox2, paraLower = c(0, 0), paraUpper = c(20, 5000)),
# The fifth model
list(model = tox1, paraLower = 0, paraUpper = 20)
)
# ----------------------------------------------------------------------------
# 3. Create distance function using C++ codes (faster)
# ----------------------------------------------------------------------------
# Square difference between two models
sq_diff <- cppFunction('
Rcpp::NumericVector gamma_diff(Rcpp::NumericVector xt, Rcpp::NumericVector xr) {
Rcpp::NumericVector div(xt.size()); double diff;
for (int i = 0; i < xt.size(); i++) {
diff = xt(i) - xr(i); div(i) = diff*diff;
}
return div;
}')
# Or, create distance function using R codes
#sq_diff <- function(xt, xr) (xt - xr)^2
# ----------------------------------------------------------------------------
# 4. Set PSO-QN Algorithm Parameters
# ----------------------------------------------------------------------------
# Set PSO options for pariwise discrimination design cases
PSO_INFO <- getPSOInfo(nSwarm = 32, maxIter = 200)
# Set L-BFGS algorithm options
LBFGS_INFO <- getLBFGSInfo(LBFGS_RETRY = 4)
# ----------------------------------------------------------------------------
# 5-1. Run PSO-QN for the case: tox4 vs. tox5
# ----------------------------------------------------------------------------
# Get list for two models
two_model_tox_54 <- list(model_tox[[1]], model_tox[[2]])
# Run PSO-QN algorithm
res_tox_54 <- DiscrimOD(MODEL_INFO = two_model_tox_54, DISTANCE = sq_diff, nSupp = 3,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO,
seed = 10, verbose = TRUE)
# Check the result
names(res_tox_54)
# $BESTDESIGN: the best design found by the PSO-QN algorithm
# $BESTVAL: the criterion value of the best design
# $GBESTHIST: the updating path of the cirterion value in PSO loop
# $CPUTIME: the computing time
res_tox_54$BESTDESIGN
# dim_1 weight
#obs_1 0.0000 0.2490446
#obs_2 468.1551 0.4979529
#obs_3 1064.1772 0.2530025
res_tox_54$BESTVAL
# 0.02884558
# Check by the equivalence theorem
eqv_tox_54 <- equivalence(ngrid = 100, PSO_RESULT = res_tox_54,
MODEL_INFO = two_model_tox_54, DISTANCE = sq_diff,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO)
names(eqv_tox_54)
# $Grid_1: the grid on the design space
# $Grid_2: (currently not used)
# $DirDeriv: the values of directional derivative function on the grid
# $MAX_DD: the maximal value of the directional derivative function
eqv_tox_54$MAX_DD
# 5.778352e-06
# Draw the curve of directional derivative function
plot(eqv_tox_54$Grid_1, eqv_tox_54$DirDeriv, type = "l", col = "black",
xlab = "x", ylab = "Directional Derivative",
main = "T-optimal design for case tox_4 vs. tox_5")
abline(h = 0, col = "grey50", lty = 2)
points(res_tox_54$BESTDESIGN[,1], rep(0, nrow(res_tox_54$BESTDESIGN)), pch = 16)
# ----------------------------------------------------------------------------
# 5-2. Run PSO-QN for the case: tox_3 vs. tox_5
# ----------------------------------------------------------------------------
# Get list for two models
two_model_tox_53 <- list(model_tox[[1]], model_tox[[3]])
# Run PSO-QN algorithm
res_tox_53 <- DiscrimOD(MODEL_INFO = two_model_tox_53, DISTANCE = sq_diff, nSupp = 4,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO,
seed = 10, verbose = TRUE)
res_tox_53$BESTDESIGN
# dim_1 weight
#obs_1 0.0000 0.09163725
#obs_2 484.2106 0.27993154
#obs_3 963.1444 0.40728475
#obs_4 1250.0000 0.22114646
res_tox_53$BESTVAL
# 0.008210951
# Check by the equivalence theorem
eqv_tox_53 <- equivalence(ngrid = 100, PSO_RESULT = res_tox_53,
MODEL_INFO = two_model_tox_53, DISTANCE = sq_diff,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO)
eqv_tox_53$MAX_DD
# 2.259953e-06
# Draw the curve of directional derivative function
plot(eqv_tox_53$Grid_1, eqv_tox_53$DirDeriv, type = "l", col = "black",
xlab = "x", ylab = "Directional Derivative",
main = "T-optimal design for case tox_3 vs. tox_5")
abline(h = 0, col = "grey50", lty = 2)
points(res_tox_53$BESTDESIGN[,1], rep(0, nrow(res_tox_53$BESTDESIGN)), pch = 16)
# ----------------------------------------------------------------------------
# 5-3. Run PSO-QN for the case: tox_2 vs. tox_5
# ----------------------------------------------------------------------------
# Get list for two models
two_model_tox_52 <- list(model_tox[[1]], model_tox[[4]])
# Run PSO-QN algorithm
res_tox_52 <- DiscrimOD(MODEL_INFO = two_model_tox_52, DISTANCE = sq_diff, nSupp = 3,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO,
seed = 1, verbose = TRUE)
res_tox_52$BESTDESIGN
# dim_1 weight
#obs_1 0.0000 0.2490425
#obs_2 468.1555 0.4979458
#obs_3 1064.1777 0.2530117
res_tox_52$BESTVAL
# 0.02884551
# Check by the equivalence theorem
eqv_tox_52 <- equivalence(ngrid = 100, PSO_RESULT = res_tox_52,
MODEL_INFO = two_model_tox_52, DISTANCE = sq_diff,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO)
eqv_tox_52$MAX_DD
# -1.243975e-07
# Draw the curve of directional derivative function
plot(eqv_tox_52$Grid_1, eqv_tox_52$DirDeriv, type = "l", col = "black",
xlab = "x", ylab = "Directional Derivative",
main = "T-optimal design for case tox_2 vs. tox_5")
abline(h = 0, col = "grey50", lty = 2)
points(res_tox_52$BESTDESIGN[,1], rep(0, nrow(res_tox_52$BESTDESIGN)), pch = 16)
# ----------------------------------------------------------------------------
# 5-4. Run PSO-QN for the case: tox_1 vs. tox_5
# ----------------------------------------------------------------------------
# Get list for two models
two_model_tox_51 <- list(model_tox[[1]], model_tox[[5]])
# Run PSO-QN algorithm
res_tox_51 <- DiscrimOD(MODEL_INFO = two_model_tox_51, DISTANCE = sq_diff, nSupp = 2,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO,
seed = 10, verbose = TRUE)
res_tox_51$BESTDESIGN
# dim_1 weight
#obs_1 0 0.5000002
#obs_2 1250 0.4999998
res_tox_51$BESTVAL
# 0.3021931
# Check by the equivalence theorem
eqv_tox_51 <- equivalence(ngrid = 100, PSO_RESULT = res_tox_51,
MODEL_INFO = two_model_tox_51, DISTANCE = sq_diff,
dsLower = 0, dsUpper = 1250, crit_type = "pair_fixed_true",
PSO_INFO = PSO_INFO, LBFGS_INFO = LBFGS_INFO)
eqv_tox_51$MAX_DD
# 1.317739e-07
# Draw the curve of directional derivative function
plot(eqv_tox_51$Grid_1, eqv_tox_51$DirDeriv, type = "l", col = "black",
xlab = "x", ylab = "Directional Derivative",
main = "T-optimal design for case tox_1 vs. tox_5")
abline(h = 0, col = "grey50", lty = 2)
points(res_tox_51$BESTDESIGN[,1], rep(0, nrow(res_tox_51$BESTDESIGN)), pch = 16)
# ----------------------------------------------------------------------------
# 6. Run PSO-S-QN for max-min KL-optimal design for all models
# ----------------------------------------------------------------------------
# Set PSO options for pariwise discrimination design cases
PSO_MM_INFO <- getPSOInfo(nSwarm = 32, maxIter = 400)
# Get the values of T-optimal criterion found previouly which will be
# the denominators of the T-efficiencies
eff_denom <- c(res_tox_54$BESTVAL, res_tox_53$BESTVAL, res_tox_52$BESTVAL, res_tox_51$BESTVAL)
res_tox <- DiscrimOD(MODEL_INFO = model_tox, DISTANCE = sq_diff, nSupp = 4,
dsLower = 0, dsUpper = 1250, crit_type = "maxmin_fixed_true",
MaxMinStdVals = eff_denom,
PSO_INFO = PSO_MM_INFO, LBFGS_INFO = LBFGS_INFO,
seed = 10, verbose = TRUE)
# Check the result
names(res_tox)
# $BESTDESIGN: the best design found by the PSO-QN algorithm
# $BESTVAL: the criterion value of the best design
# $GBESTHIST: the updating path of the cirterion value in PSO loop
# $CPUTIME: the computing time
res_tox$BESTDESIGN
# dim_1 weight
#obs_1 0.0000 0.2116546
#obs_2 425.7768 0.3443724
#obs_3 1026.8400 0.2526005
#obs_4 1250.0000 0.1913725
res_tox$BESTVAL
# 0.7741035
eqv_tox <- equivalence(ngrid = 100, PSO_RESULT = res_tox,
MODEL_INFO = model_tox, DISTANCE = sq_diff,
dsLower = 0, dsUpper = 1250, crit_type = "maxmin_fixed_true",
MaxMinStdVals = eff_denom,
PSO_INFO = PSO_MM_INFO, LBFGS_INFO = LBFGS_INFO)
names(eqv_tox)
# $Grid_1: the grid on the design space
# $Grid_2: (currently not used)
# $DirDeriv: the values of directional derivative function on the grid
# $MAX_DD: the maximal value of the directional derivative function
# $alpha: the best weight vector of the efficiency values
eqv_tox$MAX_DD
# 0.005925543
# Draw the curve of directional derivative function
plot(eqv_tox$Grid_1, eqv_tox$DirDeriv, type = "l", col = "black",
xlab = "x", ylab = "Directional Derivative",
main = "max-min T-optimal design for toxicology example")
abline(h = 0, col = "grey50", lty = 2)
points(res_tox$BESTDESIGN[,1], rep(0, nrow(res_tox$BESTDESIGN)), pch = 16)
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