#' ---
#' title: "Multi Layer Optimization Demo"
#' author: Ross Bennett
#' date: "7/17/2014"
#' ---
#' Demonstrate multi layer portfolio optimization
#' The top level (i.e. layer) optimization problem is to minimize modified ES
#' with equal component contribution to modified ES of the two portfolios in
#' the lower layer.
#'
#' The sub portfolios consist of different assets and different objectives
#' relative to each other. The out of sample returns for each sub portfolio
#' are calculated based on their respective constraints, objectives, and
#' optimization parameters. The out of sample returns are then used as the
#' returns input for the top level optimization.
#' Load package and data.
library(PortfolioAnalytics)
data(edhec)
R <- edhec[, 1:10]
funds <- colnames(R)
#' The first sub-portfolio, portf1, will contain assets 1:5 of edhec
#' with an objective to minimize standard deviation.
portf1 <- portfolio.spec(assets=funds[1:5])
portf1 <- add.constraint(portfolio=portf1, type="weight_sum",
min_sum=0.99, max_sum=1.01)
portf1 <- add.constraint(portfolio=portf1, type="long_only")
portf1 <- add.objective(portfolio=portf1, type="risk", name="StdDev")
#' The second sub-portfolio, portf2, will contain assets 6:10 of edhec
#' with an objective to minimize expected shortfall.
portf2 <- portfolio.spec(assets=funds[6:10])
# portf2 <- portfolio.spec(assets=5)
portf2 <- add.constraint(portfolio=portf2, type="weight_sum",
min_sum=0.99, max_sum=1.01)
portf2 <- add.constraint(portfolio=portf2, type="long_only")
portf2 <- add.objective(portfolio=portf2, type="risk", name="ES",
arguments=list(p=0.9))
#' portf1 and portf2 have the same constraints so they can used the same
#' set of random portfolios.
set.seed(123)
rp <- random_portfolios(portf2, 2000)
#' The 'top level' portfolio has objectives for equal contribution to risk
#' where modified ES is the risk measure.
portf <- portfolio.spec(assets=paste("proxy",1:2, sep="."))
portf <- add.constraint(portfolio=portf, type="weight_sum",
min_sum=0.99, max_sum=1.01)
portf <- add.constraint(portfolio=portf, type="long_only")
portf <- add.objective(portfolio=portf, type="risk", name="ES",
arguments=list(p=0.9))
portf <- add.objective(portfolio=portf, type="risk_budget", name="ES",
arguments=list(p=0.9), min_concentration=TRUE)
#' Specify a mult-layer portfolio.
mult.portf <- mult.portfolio.spec(portf)
#' Add portf1 as a sub portfolio with optimization parameters specific to
#' running optimize.portfolio.rebalancing with portf1.
mult.portf <- add.sub.portfolio(mult.portf, portf1, rp=rp,
optimize_method="random",
rebalance_on="quarters",
training_period=136)
#' Add portf2 as a sub portfolio with optimization parameters specific to
#' running optimize.portfolio.rebalancing with portf2.
mult.portf <- add.sub.portfolio(mult.portf, portf2, rp=rp,
optimize_method="random",
rebalance_on="months",
training_period=136,
trailing_periods=48)
#' Generate random portfolios for the top layer optimization
set.seed(123)
rp.top <- random_portfolios(portf, 1000)
#' Run the multi layer optimization
opt.mult <- optimize.portfolio(R, mult.portf,
optimize_method="random",
trace=TRUE, rp=rp.top)
opt.mult
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