randport.eval {PortfolioProbe} | R Documentation

## Evaluate Each Random Portfolio

### Description

Takes a random portfolio object and evaluates each individual portfolio. Any set of components of the output of `trade.optimizer` can be saved.

### Usage

    randport.eval(x, keep = c("results", "alpha.values", "var.values",
            "utility.values"), subset = NULL, do.warn = FALSE,
            additional.args = NULL, checkinput = TRUE, FUN = NULL, ...)

### Arguments

`x` | required. An object that is the result of a call to `random.portfolio` or `random.portfolio.utility`.
`keep` | character vector of the names of components of the output of `trade.optimizer`. If this is `NULL`, then the slightly ironic result is that all components are kept.
`subset` | either `NULL` or a vector to subscript along the components of `x`.
`do.warn` | the control for the warnings coming from `trade.optimizer`. The default is `FALSE`, meaning all warnings are turned off that can be turned off. The two other likely values are: `TRUE` (turn on all warnings), and `NULL` (use the `do.warn` value that was in effect to start with). (A value of `NULL` here is not necessarily the same as `NULL` in `trade.optimizer`.) In general, this can be any value that the `do.warn` argument to `trade.optimizer` will accept.
`additional.args` | a list of arguments to `trade.optimizer` either not in the call to `random.portfolio` or that should be changed. In the latter case, argument names need to be given exactly the same as in the original – that is, with the same amount of abbreviation.
`checkinput` | a logical value. If `TRUE`, then a (fallible) check is made to see if there is a change in the value of `price`, `variance`, `expected.return` or `existing` between the current computation and the original computation. There is no warning about arguments that are in `additional.args`.
`FUN` | a function or a character string naming a function. Each portfolio trade object will be passed to the function.
`...` | additional arguments given to `FUN`.

### Value

a list as long as `x` (or by what is indicated by `subset` if given).
If `FUN` is not given, each component is a list containing the components of the output of `trade.optimizer` listed in `keep`.
If `FUN` is given, then each component is the result of `FUN` applied to the portfolio trade object for the component.

### Details

The objects that are involved (like prices and variances) need to be available in the current session, and presumably should be unchanged.

If you get a warning about a "checkinput difference" for one or more arguments, then you probably want to add those arguments to `additional.args`. Problems like this can arise because the arguments for the original computation were dependent on the iteration in a loop. Outside that original loop the value may be interpreted differently (or cause an error).

### Bugs

This depends on the default value of `out.trade` in `random.portfolio` (and `random.portfolio.utility`) remaining `FALSE`.

### Revision

This help was last revised 2010 January 02.

### See Also

`random.portfolio`, `trade.optimizer`, `random.portfolio.utility`.

### Examples

    randport1 <- random.portfolio(100, prices, variance=varian,
            long.only=TRUE, bench.constr=c(spx=.04^2/252),
            lin.constraints=cntrysect.conmat,
            lin.bounds=cntrysect.bounds, gross.value=1e6)

    randeval1 <- randport.eval(randport1)

    # look at linear constraints of the random portfolios
    randlincon1 <- randport.eval(randport1, keep="lin.realized")

    # returns the above plus more
    randsummary <- randport.eval(randport1, FUN=summary)

[Package PortfolioProbe version 1.00 Index]