Common Operations on the PortfolioMAD Object

Naming a PortfolioMAD Object

To name aPortfolioMADobject, use theNameproperty.Nameis informational and has no effect on any portfolio calculations. If theNameproperty is nonempty,Nameis the title for the efficient frontier plot generated byplotFrontier. For example, if you set up an asset allocation fund, you could name thePortfolioMADobject Asset Allocation Fund:

p = PortfolioMAD('Name','Asset Allocation Fund'); disp(p.Name); AssetAllocationFund

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The fundamental quantity in thePortfolioMADobject is the number of assets in the asset universe. This quantity is maintained in theNumAssetsproperty. Although you can set this property directly, it is usually derived from other properties such as the number of assets in the scenarios or the initial portfolio. In some instances, the number of assets may need to be set directly. This example shows how to set up aPortfolioMADobject that has four assets:

p = PortfolioMAD('NumAssets', 4); disp(p.NumAssets)

After setting theNumAssetsproperty, you cannot modify it (unless no other properties are set that depend onNumAssets). The only way to change the number of assets in an existingPortfolioMADobject with a known number of assets is to create a newPortfolioMADobject.

Setting Up a List of Asset Identifiers

When working with portfolios, you must specify a universe of assets. Although you can perform a complete analysis without naming the assets in your universe, it is helpful to have an identifier associated with each asset as you create and work with portfolios. You can create a list of asset identifiers as a cell vector of character vectors in the propertyAssetList. You can set up the list using the next two methods.

Setting Up Asset Lists Using the PortfolioMAD Function

Suppose that you have aPortfolioMADobject,p, with assets with symbols'AA'','BA','CAT','DD', and'ETR'. You can create a list of these asset symbols in the object usingPortfolioMAD:

p = PortfolioMAD('assetlist', {'AA','BA','CAT','DD','ETR'});disp (p.AssetList)

'AA' 'BA' 'CAT' 'DD' 'ETR'

Notice that the propertyAssetListis maintained as a cell array that contains character vectors, and that it is necessary to pass a cell array intoPortfolioMADto setAssetList. In addition, notice that the propertyNumAssetsis set to5based on the number of symbols used to create the asset list:

disp(p.NumAssets)

Setting Up Asset Lists Using the setAssetList Function

You can also specify a list of assets using thesetAssetListfunction. Given the list of asset symbols'AA','BA','CAT','DD', and'ETR', you can usesetAssetListwith:

p = PortfolioMAD; p = setAssetList(p, {'AA','BA','CAT','DD','ETR'});disp (p.AssetList)

'AA' 'BA' 'CAT' 'DD' 'ETR'

setAssetListalso enables you to enter symbols directly as a comma-separated list without creating a cell array of character vectors. For example, given the list of assets symbols'AA','BA','CAT','DD', and'ETR', usesetAssetList:

p = PortfolioMAD; p = setAssetList(p,'AA','BA','CAT','DD','ETR'); disp(p.AssetList)

'AA' 'BA' 'CAT' 'DD' 'ETR'

setAssetListhas many additional features to create lists of asset identifiers. If you usesetAssetListwith just aPortfolioMADobject, it creates a default asset list according to the name specified in the hidden public propertydefaultforAssetList(which is'Asset'by default). The number of asset names created depends on the number of assets in the propertyNumAssets. IfNumAssetsis not set, thenNumAssetsis assumed to be1.

For example, if aPortfolioMADobjectpis created withNumAssets=5, then this code fragment shows the default naming behavior:

p = PortfolioMAD('numassets',5); p = setAssetList(p); disp(p.AssetList)

'Asset1' 'Asset2' 'Asset3' 'Asset4' 'Asset5'

Suppose that your assets are, for example, ETFs and you change the hidden propertydefaultforAssetListto'ETF', you can then create a default list for ETFs:

p = PortfolioMAD('numassets',5); p.defaultforAssetList ='ETF'; p = setAssetList(p); disp(p.AssetList)

'ETF1' 'ETF2' 'ETF3' 'ETF4' 'ETF5'

Truncating and Padding Asset Lists

如果NumAssetsproperty is already set and you pass in too many or too few identifiers, thePortfolioMADobject, and thesetAssetListfunction truncate or pad the list with numbered default asset names that use the name specified in the hidden public propertydefaultforAssetList. If the list is truncated or padded, a warning message indicates the discrepancy. For example, assume that you have aPortfolioMADobject with five ETFs and you only know the first three CUSIPs'921937835','922908769', and'922042775'. Use this syntax to create an asset list that pads the remaining asset identifiers with numbered'UnknownCUSIP'placeholders:

p = PortfolioMAD('numassets',5); p.defaultforAssetList ='UnknownCUSIP'; p = setAssetList(p,'921937835','922908769','922042775'); disp(p.AssetList)

Warning: Input list of assets has 2 too few identifiers. Padding with numbered assets. > In PortfolioMAD.setAssetList at 121 Columns 1 through 4 '921937835' '922908769' '922042775' 'UnknownCUSIP4' Column 5 'UnknownCUSIP5'

Alternatively, suppose that you have too many identifiers and need only the first four assets. This example illustrates truncation of the asset list using thePortfolioMADobject:

p = PortfolioMAD('numassets',4); p = PortfolioMAD(p,'assetlist', {'AGG','EEM','MDY','SPY','VEU'});disp (p.AssetList)

Warning: AssetList has 1 too many identifiers. Using first 4 assets. > In PortfolioMAD.checkarguments at 410 In PortfolioMAD.PortfolioMAD>PortfolioMAD.PortfolioMAD at 187 'AGG' 'EEM' 'MDY' 'SPY'

The hidden public propertyuppercaseAssetListis a Boolean flag to specify whether to convert asset names to uppercase letters. The default value foruppercaseAssetListisfalse. This example shows how to use theuppercaseAssetListflag to force identifiers to be uppercase letters:

p = PortfolioMAD; p.uppercaseAssetList = true; p = setAssetList(p, {'aa','ba','cat','dd','etr'});disp (p.AssetList)

'AA' 'BA' 'CAT' 'DD' 'ETR'