# Computes new design points for ATM `atm.nextpts` computes new design points to evaluate using a randomized orthogonal array (OA). package ```r atm.nextpts(atm.obj,reps=NULL) ``` ## Arguments - `atm.obj`: Current ATM object. - `reps`: Number of desired replications for OA. ## Examples ```r ## Not run: #################################################### # Example 1: detpep10exp (9-D) #################################################### nfact <- 9 #number of factors ntimes <- floor(nfact/3) #number of "repeats" for detpep10exp lev <- 4 #number of levels nlev <- rep(lev,nfact) #number of levels for each factor nelim <- 3 #number of level eliminations fn <- function(xx){detpep10exp(xx,ntimes,nlev)} #objective to minimize (assumed expensive) #initialize objects # (predicts & removes levels based on tuned ATM percentages) fit.atm <- atm.init(nfact,nlev) #initialize sel.min object # (predicts minimum using smallest observed value & removes levels with largest minima) fit.min <- atm.init(nfact,nlev) #Run for nelim eliminations: res.atm <- rep(NA,nelim) #for ATM results res.min <- rep(NA,nelim) #for sel.min results for (i in 1:nelim){ # ATM updates: new.des <- atm.nextpts(fit.atm) #get design points new.obs <- apply(new.des,1,fn) #sample function fit.atm <- atm.addpts(fit.atm,new.des,new.obs) #add data to object fit.atm <- atm.predict(fit.atm) #predict minimum setting idx.atm <- fit.atm$idx.opt res.atm[i] <- fn(idx.atm) fit.atm <- atm.remlev(fit.atm) #removes worst performing level # sel.min updates: new.des <- atm.nextpts(fit.min) #get design points new.obs <- apply(new.des,1,fn) #sample function fit.min <- atm.addpts(fit.min,new.des,new.obs) #add data to object fit.min <- atm.predict(fit.min, alphas=rep(0,nfact)) #find setting with smallest observation idx.min <- fit.min$idx.opt res.min[i] <- fn(idx.min) #check: min(fit.min$obs.all) fit.min <- atm.remlev(fit.min) #removes worst performing level } res.atm res.min #conclusion: ATM finds better solutions by learning & exploiting additive structure #################################################### # Example 2: camel6 (24-D) #################################################### nfact <- 24 #number of factors ntimes <- floor(nfact/2.0) #number of "repeats" for camel6 lev <- 4 nlev <- rep(lev,nfact) #number of levels for each factor nelim <- 3 #number of level eliminations fn <- function(xx){camel6(xx,ntimes,nlev)} #objective to minimize (assumed expensive) #initialize objects # (predicts & removes levels based on tuned ATM percentages) fit.atm <- atm.init(nfact,nlev) #initialize sel.min object # (predicts minimum using smallest observed value & removes levels with largest minima) fit.min <- atm.init(nfact,nlev) #Run for nelim eliminations: res.atm <- rep(NA,nelim) #for ATM results res.min <- rep(NA,nelim) #for sel.min results for (i in 1:nelim){ # ATM updates: new.des <- atm.nextpts(fit.atm) #get design points new.obs <- apply(new.des,1,fn) #sample function fit.atm <- atm.addpts(fit.atm,new.des,new.obs) #add data to object fit.atm <- atm.predict(fit.atm) #predict minimum setting idx.atm <- fit.atm$idx.opt res.atm[i] <- fn(idx.atm) fit.atm <- atm.remlev(fit.atm) #removes worst performing level # sel.min updates: new.des <- atm.nextpts(fit.min) #get design points new.obs <- apply(new.des,1,fn) #sample function fit.min <- atm.addpts(fit.min,new.des,new.obs) #add data to object fit.min <- atm.predict(fit.min, alphas=rep(0,nfact)) #find setting with smallest observation idx.min <- fit.min$idx.opt res.min[i] <- fn(idx.min) #check: min(fit.min$obs.all) fit.min <- atm.remlev(fit.min) #removes worst performing level } res.atm res.min #conclusion: ATM finds better solutions by learning & exploiting additive structure ## End(Not run) ```

atm.nextpts function