Using Programs in Datastream

USING PROGRAMS WITHIN DATASTREAM

Programs, in combination with correct data codes, are what enable users of Datastream to obtain the specific information they need. After choosing the general format of output (Type of Request) and the general type of information (Type of Data), Datastream displays the programs available within those limits. The image above shows some of the programs available in time series statistics for economics data.

Programs are numbered. By specifying the type of request and type of data, you are trying to find the Datastream program your search will require. To select a program from the list displayed, click on the text of the particular program item with the left mouse button of the computer. After doing this, a program number will appear in the command line area of the Datastream window. You have successfully found part of the information required to execute a search. If you know the number of the program you wish to use, at any time, type the program number into the main command line area and press enter. Pressing enter is the equivalent of double-clicking on the selected program with the left mouse button.

Having selected a search program, the user will then be prompted to enter the parameters of the desired search. The types of input which will now be required can vary greatly with one's choice of program. Because programs require many different types of input, it is sometimes necessary to try a program once in order to determine what variables will be requested. Most programs in Datastream will require the user to enter a code to specify what series of data is to be displayed, followed by several other variables which will determine which parts and how much of the series of data should be displayed (i.e., monthly, from February through September of 1993). Finding correct data codes is equally important to finding correct programs.

CODES IN DATASTREAM

The thousands of types of data that are maintained by Datastream are only manageable through the use of codes. Codes allow the user to specify with precision exactly what the user wishes to obtain. Understanding codes and how they may be found is of the utmost importance if one is to learn how to use Datastream.

A code is simply a number or mnemonic assigned to a type of data to promote a uniformity in methods of series identification. For instance, if I wanted to know about the stock of Novell on a particular day, I could not simply select a program and enter the word Novell when prompted for an item to search for. I would first have to look up the code for Novell's stock, 729152. Finding the correct code, however, is a matter that requires care.

HOW TO FIND THE CODE YOU NEED

If you are familiar with programs in Datastream, you will find that the first thing you will want to look up when beginning a search is the data code you will be using. There are two useful methods for looking up data codes. The first is a program for looking up data codes by keyword that may be accessed by typing CODE in the program number box. This method is preferred for its specificity. One may enter a keyword and specify what type of financial instruments one wishes to search (i.e., equities, bonds, futures, etc.) and in what currency one would wish the data to be denominated. By entering the word Novell and choosing to search equities in US currency, four possible codes are obtained. The desired data code is easily chosen.

The second method of searching for codes in Datastream may be used by clicking on the CODE button at the top, left hand side of the Datastream windows. This program is similar to the program described above, but it differs in that it searches a collection of codes that resides on the particular computer you are using. The method discussed previously will search for codes online, where they are likely to be most up to date.

DATATYPES

The second part of finding a code is finding the correct datatype. Datatypes allow you to retrieve different types of data within one series. For instance, the default representation of the series code for the equity Novell is the closing price. To obtain the daily high price for Novell, append the datatype PH to the Novell series code @NOVL, making @NOVL(PH). For help finding the datatypes available for codes in Datastream use the program HELP DT?