[Returnanalytics-commits] r2800 - in pkg/PortfolioAnalytics: R man

noreply at r-forge.r-project.org noreply at r-forge.r-project.org
Fri Aug 16 19:51:30 CEST 2013


Author: rossbennett34
Date: 2013-08-16 19:51:30 +0200 (Fri, 16 Aug 2013)
New Revision: 2800

Modified:
   pkg/PortfolioAnalytics/R/constraints.R
   pkg/PortfolioAnalytics/man/add.constraint.Rd
   pkg/PortfolioAnalytics/man/box_constraint.Rd
   pkg/PortfolioAnalytics/man/constraint.Rd
   pkg/PortfolioAnalytics/man/constraint_v2.Rd
   pkg/PortfolioAnalytics/man/diversification_constraint.Rd
   pkg/PortfolioAnalytics/man/factor_exposure_constraint.Rd
   pkg/PortfolioAnalytics/man/group_constraint.Rd
   pkg/PortfolioAnalytics/man/position_limit_constraint.Rd
   pkg/PortfolioAnalytics/man/return_constraint.Rd
   pkg/PortfolioAnalytics/man/turnover_constraint.Rd
   pkg/PortfolioAnalytics/man/weight_sum_constraint.Rd
Log:
updating documentation for constraints

Modified: pkg/PortfolioAnalytics/R/constraints.R
===================================================================
--- pkg/PortfolioAnalytics/R/constraints.R	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/R/constraints.R	2013-08-16 17:51:30 UTC (rev 2800)
@@ -154,13 +154,13 @@
 
 #' constructor for class v2_constraint
 #' 
-#' @param type character type of the constraint to add or update, currently 'weight_sum', 'box', or 'group'
+#' This function is called by the constructor for the specific constraint.
+#' 
+#' @param type character type of the constraint to add or update
 #' @param assets number of assets, or optionally a named vector of assets specifying seed weights
 #' @param ... any other passthru parameters
 #' @param constrclass character to name the constraint class
 #' @author Ross Bennett
-#' @aliases constraint
-#' @rdname constraint
 #' @export
 constraint_v2 <- function(type, enabled=TRUE, ..., constrclass="v2_constraint"){
   if(!hasArg(type)) stop("you must specify a constraint type")
@@ -181,18 +181,70 @@
 
 #' General interface for adding and/or updating optimization constraints.
 #' 
-#' This is the main function for adding and/or updating constraints in an object of type \code{\link{portfolio}}.
+#' This is the main function for adding and/or updating constraints to the \code{{portfolio}} object.
 #' 
-#' Special cases for the weight_sum constraint are "full_investment" and "dollar_nuetral" or "active" with appropriate values set for min_sum and max_sum. see \code{\link{weight_sum_constraint}}
+#' The following constraint types are supported:
+#' \itemize{
+#' \item{\code{weight_sum}, \code{weight}, \code{leverage}}{ Specify constraint on the sum of the weights, see \code{\link{weight_sum_constraint}}}
+#' \item{\code{full_investment}}{ Special case to set \code{min_sum=1} and \code{max_sum=1} of weight sum constraints}
+#' \item{\code{dollar_neutral}, \code{active}}{ Special case to set \code{min_sum=0} and \code{max_sum=0} of weight sum constraints}
+#' \item{\code{box}}{ Specify constraints for the individual asset weights, see \code{\link{box_constraint}}}
+#' \item{\code{long_only}}{ Special case to set \code{min=0} and \code{max=1} of box constraints}
+#' \item{\code{group}}{ Specify a constraint on the sum of weights within groups and the number of assets with non-zero weights in groups, see \code{\link{group_constraint}}}
+#' \item{\code{turnover}}{ Specify a constraint for target turnover. Turnover is calculated from a set of initial weights, see \code{\link{turnover_constraint}}}
+#' \item{\code{diversification}}{ Specify a constraint for target diversification of a set of weights, see \code{\link{diversification_constraint}}}
+#' \item{\code{position_limit}}{ Specify a constraint on the number of positions (i.e. assets with non-zero weights as well as the number of long and short positions, see \code{\link{position_limit_constraint}}}
+#' \item{\code{return}}{ Specify a constraint for target mean return, see \code{\link{return_constraint}}}
+#' \item{\code{factor_exposure}}{ Specify a constraint for risk factor exposures, see \code{\link{factor_exposure_constraint}}}
+#' }
 #' 
 #' @param portfolio an object of class 'portfolio' to add the constraint to, specifying the constraints for the optimization, see \code{\link{portfolio.spec}}
 #' @param type character type of the constraint to add or update, currently 'weight_sum' (also 'leverage' or 'weight'), 'box', 'group', 'turnover', 'diversification', 'position_limit', 'return', or 'factor_exposure'
-#' @param enabled TRUE/FALSE
+#' @param enabled TRUE/FALSE. The default is enabled=TRUE.
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify constraints
-#' @param indexnum if you are updating a specific constraint, the index number in the $objectives list to update
+#' @param indexnum if you are updating a specific constraint, the index number in the $constraints list to update
 #' @author Ross Bennett
-#' @seealso \code{\link{constraint_v2}}, \code{\link{weight_sum_constraint}}, \code{\link{box_constraint}}, \code{\link{group_constraint}}, \code{\link{turnover_constraint}}, \code{\link{diversification_constraint}}, \code{\link{position_limit_constraint}}
+#' @seealso \code{\link{weight_sum_constraint}}, \code{\link{box_constraint}}, \code{\link{group_constraint}}, \code{\link{turnover_constraint}}, \code{\link{diversification_constraint}}, \code{\link{position_limit_constraint}, \code{\link{return_constraint}, \code{\link{factor_exposure_constraint}}
+#' @examples
+#' data(edhec)
+#' returns <- edhec[, 1:4]
+#' fund.names <- colnames(returns)
+#' pspec <- portfolio.spec(assets=fund.names)
+#' # Add the full investment constraint that specifies the weights must sum to 1.
+#' pspec <- add.constraint(portfolio=pspec, type="weight_sum", min_sum=1, max_sum=1)
+#' # The full investment constraint can also be specified with type="full_investment"
+#' pspec <- add.constraint(portfolio=pspec, type="full_investment")
+#' 
+#' # Another common constraint is that portfolio weights sum to 0.
+#' pspec <- add.constraint(portfolio=pspec, type="weight_sum", min_sum=0, max_sum=0)
+#' pspec <- add.constraint(portfolio=pspec, type="dollar_neutral")
+#' pspec <- add.constraint(portfolio=pspec, type="active")
+#' 
+#' # Add box constraints
+#' pspec <- add.constraint(portfolio=pspec, type="box", min=0.05, max=0.4)
+#' 
+#' min and max can also be specified per asset
+#' pspec <- add.constraint(portfolio=pspec, type="box", min=c(0.05, 0, 0.08, 0.1), max=c(0.4, 0.3, 0.7, 0.55))
+#' # A special case of box constraints is long only where min=0 and max=1
+#' # The default action is long only if min and max are not specified
+#' pspec <- add.constraint(portfolio=pspec, type="box")
+#' pspec <- add.constraint(portfolio=pspec, type="long_only")
+#' 
+#' # Add group constraints
+#' pspec <- add.constraint(portfolio=pspec, type="group", groups=c(3, 1), group_min=c(0.1, 0.15), group_max=c(0.85, 0.55), group_labels=c("GroupA", "GroupB"), group_pos=c(2, 1))
+#' 
+#' # Add position limit constraint such that we have a maximum number of three assets with non-zero weights.
+#' pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos=3)
+#' 
+#' # Add diversification constraint
+#' pspec <- add.constraint(portfolio=pspec, type="diversification", div_target=0.7)
+#' 
+#' # Add turnover constraint
+#' pspec <- add.constraint(portfolio=pspec, type="turnover", turnover_target=0.2)
+#' 
+#' # Add target mean return constraint
+#' pspec <- add.constraint(portfolio=pspec, type="return", return_target=0.007)
 #' @export
 add.constraint <- function(portfolio, type, enabled=TRUE, message=FALSE, ..., indexnum=NULL){
   # Check to make sure that the portfolio passed in is a portfolio object
@@ -296,6 +348,7 @@
 
 #' constructor for box_constraint.
 #' 
+#' Box constraints specify the upper and lower bounds on the weights of the assets.
 #' This function is called by add.constraint when type="box" is specified. see \code{\link{add.constraint}}
 #'
 #' @param type character type of the constraint
@@ -416,6 +469,7 @@
 
 #' constructor for group_constraint
 #' 
+#' Group constraints specify the grouping of the assets, weights of the groups, and number of postions (i.e. non-zero weights) iof the groups.
 #' This function is called by add.constraint when type="group" is specified. see \code{\link{add.constraint}}
 #'
 #' @param type character type of the constraint
@@ -495,14 +549,14 @@
 
 #' constructor for weight_sum_constraint
 #' 
+#' THe constraint specifies the upper and lower bound that the weights sum to.
 #' This function is called by add.constraint when "weight_sum", "leverage", "full_investment", "dollar_neutral", or "active" is specified as the type. see \code{\link{add.constraint}}
-#' This function allows the user to specify the minimum and maximum that the weights sum to
 #' 
 #' Special cases for the weight_sum constraint are "full_investment" and "dollar_nuetral" or "active"
 #' 
-#' If type="full_investment", min_sum=1 and max_sum=1
+#' If \code{type="full_investment"}, \code{min_sum=1} and \code{max_sum=1}
 #' 
-#' If type="dollar_neutral" or type="active", min_sum=0, and max_sum=0
+#' If \code{type="dollar_neutral"} or \code{type="active"}, \code{min_sum=0}, and \code{max_sum=0}
 #' 
 #' @param type character type of the constraint
 #' @param min_sum minimum sum of all asset weights, default 0.99
@@ -511,6 +565,7 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify weight_sum constraints
 #' @author Ross Bennett
+#' @seealso \code{\link{add.constraint}}
 #' @examples
 #' data(edhec)
 #' ret <- edhec[, 1:4]
@@ -650,11 +705,13 @@
 
 #' constructor for turnover_constraint
 #' 
-#' This function is called by add.constraint when type="turnover" is specified. see \code{\link{add.constraint}}
-#' This function allows the user to specify a target turnover value
+#' The turnover constraint specifies a target turnover value. 
+#' This function is called by add.constraint when type="turnover" is specified, see \code{\link{add.constraint}}.
+#' Turnover is calculated from a set of initial weights.
 #' 
-#' Note that turnover constraint is currently only supported for global minimum 
-#' variance problem with ROI quadprog plugin
+#' Note that with the RO solvers, turnover constraint is currently only 
+#' supported for the global minimum variance and quadratic utility problems 
+#' with ROI quadprog plugin.
 #' 
 #' @param type character type of the constraint
 #' @param turnover_target target turnover value
@@ -662,6 +719,7 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify box and/or group constraints
 #' @author Ross Bennett
+#' @seealso \code{\link{add.constraint}}
 #' @examples
 #' data(edhec)
 #' ret <- edhec[, 1:4]
@@ -678,7 +736,8 @@
 
 #' constructor for diversification_constraint
 #' 
-#' This function is called by add.constraint when type="diversification" is specified, \code{\link{add.constraint}}
+#' The diversification constraint specifies a target diversification value. 
+#' This function is called by add.constraint when type="diversification" is specified, see \code{\link{add.constraint}}.
 #' 
 #' @param type character type of the constraint
 #' @param div_target diversification target value
@@ -686,6 +745,7 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify box and/or group constraints
 #' @author Ross Bennett
+#' @seealso \code{\link{add.constraint}}
 #' @examples
 #' data(edhec)
 #' ret <- edhec[, 1:4]
@@ -702,6 +762,7 @@
 
 #' constructor for return_constraint
 #' 
+#' The return constraint specifes a target mean return value.
 #' This function is called by add.constraint when type="return" is specified, \code{\link{add.constraint}}
 #' 
 #' @param type character type of the constraint
@@ -710,6 +771,7 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters
 #' @author Ross Bennett
+#' @seealso \code{\link{add.constraint}}
 #' @examples
 #' data(edhec)
 #' ret <- edhec[, 1:4]
@@ -728,6 +790,7 @@
 #' 
 #' This function is called by add.constraint when type="position_limit" is specified, \code{\link{add.constraint}}
 #' Allows the user to specify the maximum number of positions (i.e. number of assets with non-zero weights)
+#' as well as the maximum number of long and short positions.
 #' 
 #' @param type character type of the constraint
 #' @param max_pos maximum number of assets with non-zero weights
@@ -737,13 +800,15 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify position limit constraints
 #' @author Ross Bennett
-#' #' @examples
+#' @seealso \code{\link{add.constraint}}
+#' @examples
 #' data(edhec)
 #' ret <- edhec[, 1:4]
 #' 
 #' pspec <- portfolio.spec(assets=colnames(ret))
 #' 
 #' pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos=3)
+#' pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos_long=3, max_pos_short=1)
 #' @export
 position_limit_constraint <- function(type="position_limit", assets, max_pos=NULL, max_pos_long=NULL, max_pos_short=NULL, enabled=TRUE, message=FALSE, ...){
   # Get the length of the assets vector
@@ -793,6 +858,7 @@
 
 #' Constructor for factor exposure constraint
 #' 
+#' The factor exposure constraint sets upper and lower bounds on exposures to risk factors.
 #' This function is called by add.constraint when type="factor_exposure" is specified. see \code{\link{add.constraint}}
 #' 
 #' \code{B} can be either a vector or matrix of risk factor exposures (i.e. betas).
@@ -816,6 +882,7 @@
 #' @param message TRUE/FALSE. The default is message=FALSE. Display messages if TRUE.
 #' @param \dots any other passthru parameters to specify risk factor exposure constraints
 #' @author Ross Bennett
+#' @seealso \code{\link{add.constraint}}
 #' @export
 factor_exposure_constraint <- function(type="factor_exposure", assets, B, lower, upper, enabled=TRUE, message=FALSE, ...){
   # Number of assets

Modified: pkg/PortfolioAnalytics/man/add.constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/add.constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/add.constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -15,7 +15,7 @@
   'weight'), 'box', 'group', 'turnover', 'diversification',
   'position_limit', 'return', or 'factor_exposure'}
 
-  \item{enabled}{TRUE/FALSE}
+  \item{enabled}{TRUE/FALSE. The default is enabled=TRUE.}
 
   \item{message}{TRUE/FALSE. The default is message=FALSE.
   Display messages if TRUE.}
@@ -24,29 +24,97 @@
   constraints}
 
   \item{indexnum}{if you are updating a specific
-  constraint, the index number in the $objectives list to
+  constraint, the index number in the $constraints list to
   update}
 }
 \description{
   This is the main function for adding and/or updating
-  constraints in an object of type \code{\link{portfolio}}.
+  constraints to the \code{{portfolio}} object.
 }
 \details{
-  Special cases for the weight_sum constraint are
-  "full_investment" and "dollar_nuetral" or "active" with
-  appropriate values set for min_sum and max_sum. see
-  \code{\link{weight_sum_constraint}}
+  The following constraint types are supported: \itemize{
+  \item{\code{weight_sum}, \code{weight}, \code{leverage}}{
+  Specify constraint on the sum of the weights, see
+  \code{\link{weight_sum_constraint}}}
+  \item{\code{full_investment}}{ Special case to set
+  \code{min_sum=1} and \code{max_sum=1} of weight sum
+  constraints} \item{\code{dollar_neutral}, \code{active}}{
+  Special case to set \code{min_sum=0} and \code{max_sum=0}
+  of weight sum constraints} \item{\code{box}}{ Specify
+  constraints for the individual asset weights, see
+  \code{\link{box_constraint}}} \item{\code{long_only}}{
+  Special case to set \code{min=0} and \code{max=1} of box
+  constraints} \item{\code{group}}{ Specify a constraint on
+  the sum of weights within groups and the number of assets
+  with non-zero weights in groups, see
+  \code{\link{group_constraint}}} \item{\code{turnover}}{
+  Specify a constraint for target turnover. Turnover is
+  calculated from a set of initial weights, see
+  \code{\link{turnover_constraint}}}
+  \item{\code{diversification}}{ Specify a constraint for
+  target diversification of a set of weights, see
+  \code{\link{diversification_constraint}}}
+  \item{\code{position_limit}}{ Specify a constraint on the
+  number of positions (i.e. assets with non-zero weights as
+  well as the number of long and short positions, see
+  \code{\link{position_limit_constraint}}}
+  \item{\code{return}}{ Specify a constraint for target
+  mean return, see \code{\link{return_constraint}}}
+  \item{\code{factor_exposure}}{ Specify a constraint for
+  risk factor exposures, see
+  \code{\link{factor_exposure_constraint}}} }
 }
+\examples{
+data(edhec)
+returns <- edhec[, 1:4]
+fund.names <- colnames(returns)
+pspec <- portfolio.spec(assets=fund.names)
+# Add the full investment constraint that specifies the weights must sum to 1.
+pspec <- add.constraint(portfolio=pspec, type="weight_sum", min_sum=1, max_sum=1)
+# The full investment constraint can also be specified with type="full_investment"
+pspec <- add.constraint(portfolio=pspec, type="full_investment")
+
+# Another common constraint is that portfolio weights sum to 0.
+pspec <- add.constraint(portfolio=pspec, type="weight_sum", min_sum=0, max_sum=0)
+pspec <- add.constraint(portfolio=pspec, type="dollar_neutral")
+pspec <- add.constraint(portfolio=pspec, type="active")
+
+# Add box constraints
+pspec <- add.constraint(portfolio=pspec, type="box", min=0.05, max=0.4)
+
+min and max can also be specified per asset
+pspec <- add.constraint(portfolio=pspec, type="box", min=c(0.05, 0, 0.08, 0.1), max=c(0.4, 0.3, 0.7, 0.55))
+# A special case of box constraints is long only where min=0 and max=1
+# The default action is long only if min and max are not specified
+pspec <- add.constraint(portfolio=pspec, type="box")
+pspec <- add.constraint(portfolio=pspec, type="long_only")
+
+# Add group constraints
+pspec <- add.constraint(portfolio=pspec, type="group", groups=c(3, 1), group_min=c(0.1, 0.15), group_max=c(0.85, 0.55), group_labels=c("GroupA", "GroupB"), group_pos=c(2, 1))
+
+# Add position limit constraint such that we have a maximum number of three assets with non-zero weights.
+pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos=3)
+
+# Add diversification constraint
+pspec <- add.constraint(portfolio=pspec, type="diversification", div_target=0.7)
+
+# Add turnover constraint
+pspec <- add.constraint(portfolio=pspec, type="turnover", turnover_target=0.2)
+
+# Add target mean return constraint
+pspec <- add.constraint(portfolio=pspec, type="return", return_target=0.007)
+}
 \author{
   Ross Bennett
 }
 \seealso{
-  \code{\link{constraint_v2}},
   \code{\link{weight_sum_constraint}},
   \code{\link{box_constraint}},
   \code{\link{group_constraint}},
   \code{\link{turnover_constraint}},
   \code{\link{diversification_constraint}},
-  \code{\link{position_limit_constraint}}
+  \code{\link{position_limit_constraint},
+  \code{\link{return_constraint},
+  \code{\link{factor_exposure_constraint}}
 }
 

Modified: pkg/PortfolioAnalytics/man/box_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/box_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/box_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -34,8 +34,10 @@
   constraints}
 }
 \description{
-  This function is called by add.constraint when type="box"
-  is specified. see \code{\link{add.constraint}}
+  Box constraints specify the upper and lower bounds on the
+  weights of the assets. This function is called by
+  add.constraint when type="box" is specified. see
+  \code{\link{add.constraint}}
 }
 \examples{
 data(edhec)

Modified: pkg/PortfolioAnalytics/man/constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -1,14 +1,10 @@
 \name{constraint}
 \alias{constraint}
-\alias{constraint_v2}
 \title{constructor for class constraint}
 \usage{
   constraint(assets = NULL, ..., min, max, min_mult,
     max_mult, min_sum = 0.99, max_sum = 1.01,
     weight_seq = NULL)
-
-  constraint_v2(type, enabled = TRUE, ...,
-    constrclass = "v2_constraint")
 }
 \arguments{
   \item{assets}{number of assets, or optionally a named
@@ -38,29 +34,14 @@
 
   \item{weight_seq}{seed sequence of weights, see
   \code{\link{generatesequence}}}
-
-  \item{type}{character type of the constraint to add or
-  update, currently 'weight_sum', 'box', or 'group'}
-
-  \item{assets}{number of assets, or optionally a named
-  vector of assets specifying seed weights}
-
-  \item{...}{any other passthru parameters}
-
-  \item{constrclass}{character to name the constraint
-  class}
 }
 \description{
   constructor for class constraint
-
-  constructor for class v2_constraint
 }
 \examples{
 exconstr <- constraint(assets=10, min_sum=1, max_sum=1, min=.01, max=.35, weight_seq=generatesequence())
 }
 \author{
   Peter Carl and Brian G. Peterson
-
-  Ross Bennett
 }
 

Modified: pkg/PortfolioAnalytics/man/constraint_v2.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/constraint_v2.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/constraint_v2.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -7,7 +7,7 @@
 }
 \arguments{
   \item{type}{character type of the constraint to add or
-  update, currently 'weight_sum', 'box', or 'group'}
+  update}
 
   \item{assets}{number of assets, or optionally a named
   vector of assets specifying seed weights}
@@ -18,7 +18,8 @@
   class}
 }
 \description{
-  constructor for class v2_constraint
+  This function is called by the constructor for the
+  specific constraint.
 }
 \author{
   Ross Bennett

Modified: pkg/PortfolioAnalytics/man/diversification_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/diversification_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/diversification_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -19,9 +19,10 @@
   and/or group constraints}
 }
 \description{
-  This function is called by add.constraint when
-  type="diversification" is specified,
-  \code{\link{add.constraint}}
+  The diversification constraint specifies a target
+  diversification value. This function is called by
+  add.constraint when type="diversification" is specified,
+  see \code{\link{add.constraint}}.
 }
 \examples{
 data(edhec)
@@ -34,4 +35,7 @@
 \author{
   Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 

Modified: pkg/PortfolioAnalytics/man/factor_exposure_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/factor_exposure_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/factor_exposure_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -29,9 +29,10 @@
   risk factor exposure constraints}
 }
 \description{
-  This function is called by add.constraint when
-  type="factor_exposure" is specified. see
-  \code{\link{add.constraint}}
+  The factor exposure constraint sets upper and lower
+  bounds on exposures to risk factors. This function is
+  called by add.constraint when type="factor_exposure" is
+  specified. see \code{\link{add.constraint}}
 }
 \details{
   \code{B} can be either a vector or matrix of risk factor
@@ -54,4 +55,7 @@
 \author{
   Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 

Modified: pkg/PortfolioAnalytics/man/group_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/group_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/group_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -35,8 +35,10 @@
   group constraints}
 }
 \description{
-  This function is called by add.constraint when
-  type="group" is specified. see
+  Group constraints specify the grouping of the assets,
+  weights of the groups, and number of postions (i.e.
+  non-zero weights) iof the groups. This function is called
+  by add.constraint when type="group" is specified. see
   \code{\link{add.constraint}}
 }
 \examples{

Modified: pkg/PortfolioAnalytics/man/position_limit_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/position_limit_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/position_limit_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -32,7 +32,8 @@
   type="position_limit" is specified,
   \code{\link{add.constraint}} Allows the user to specify
   the maximum number of positions (i.e. number of assets
-  with non-zero weights)
+  with non-zero weights) as well as the maximum number of
+  long and short positions.
 }
 \examples{
 data(edhec)
@@ -41,8 +42,12 @@
 pspec <- portfolio.spec(assets=colnames(ret))
 
 pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos=3)
+pspec <- add.constraint(portfolio=pspec, type="position_limit", max_pos_long=3, max_pos_short=1)
 }
 \author{
-  Ross Bennett #'
+  Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 

Modified: pkg/PortfolioAnalytics/man/return_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/return_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/return_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -18,7 +18,8 @@
   \item{\dots}{any other passthru parameters}
 }
 \description{
-  This function is called by add.constraint when
+  The return constraint specifes a target mean return
+  value. This function is called by add.constraint when
   type="return" is specified, \code{\link{add.constraint}}
 }
 \examples{
@@ -32,4 +33,7 @@
 \author{
   Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 

Modified: pkg/PortfolioAnalytics/man/turnover_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/turnover_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/turnover_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -19,15 +19,16 @@
   and/or group constraints}
 }
 \description{
-  This function is called by add.constraint when
-  type="turnover" is specified. see
-  \code{\link{add.constraint}} This function allows the
-  user to specify a target turnover value
+  The turnover constraint specifies a target turnover
+  value. This function is called by add.constraint when
+  type="turnover" is specified, see
+  \code{\link{add.constraint}}. Turnover is calculated from
+  a set of initial weights.
 }
 \details{
-  Note that turnover constraint is currently only supported
-  for global minimum variance problem with ROI quadprog
-  plugin
+  Note that with the RO solvers, turnover constraint is
+  currently only supported for the global minimum variance
+  and quadratic utility problems with ROI quadprog plugin.
 }
 \examples{
 data(edhec)
@@ -40,4 +41,7 @@
 \author{
   Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 

Modified: pkg/PortfolioAnalytics/man/weight_sum_constraint.Rd
===================================================================
--- pkg/PortfolioAnalytics/man/weight_sum_constraint.Rd	2013-08-16 16:45:23 UTC (rev 2799)
+++ pkg/PortfolioAnalytics/man/weight_sum_constraint.Rd	2013-08-16 17:51:30 UTC (rev 2800)
@@ -23,21 +23,21 @@
   weight_sum constraints}
 }
 \description{
-  This function is called by add.constraint when
-  "weight_sum", "leverage", "full_investment",
-  "dollar_neutral", or "active" is specified as the type.
-  see \code{\link{add.constraint}} This function allows the
-  user to specify the minimum and maximum that the weights
-  sum to
+  THe constraint specifies the upper and lower bound that
+  the weights sum to. This function is called by
+  add.constraint when "weight_sum", "leverage",
+  "full_investment", "dollar_neutral", or "active" is
+  specified as the type. see \code{\link{add.constraint}}
 }
 \details{
   Special cases for the weight_sum constraint are
   "full_investment" and "dollar_nuetral" or "active"
 
-  If type="full_investment", min_sum=1 and max_sum=1
+  If \code{type="full_investment"}, \code{min_sum=1} and
+  \code{max_sum=1}
 
-  If type="dollar_neutral" or type="active", min_sum=0, and
-  max_sum=0
+  If \code{type="dollar_neutral"} or \code{type="active"},
+  \code{min_sum=0}, and \code{max_sum=0}
 }
 \examples{
 data(edhec)
@@ -58,4 +58,7 @@
 \author{
   Ross Bennett
 }
+\seealso{
+  \code{\link{add.constraint}}
+}
 



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