Introduction to Packages for the TSMODEL Procedure
Chapter Organization
This book is organized as follows.
This chapter provides an overview that describes what packages for the TSMODEL procedure are and how they are used.
The remaining chapters describe the various packages that are available for the TSMODEL procedure. Each of these chapters is organized as follows:
The "Overview" section describes the broad purpose of the package; it describes which specific facet of the time series analysis problem the package is designed to tackle. It also provides a table that lists all the objects and functions that are offered by the package along with a brief description of each object’s functionalities. You can use the contents of this table to quickly locate an object that offers the functionalities you need. For packages that contain objects that interact with each other to perform larger and more complex tasks, a data flow diagram is also provided in this section to succinctly describe the interactions between the various objects via their methods. The direction of the arrows in this diagram indicates how the output of object methods feeds into other object methods. This section also describes the status codes that can be returned by an object methods and functions in the packages.
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A section for each object follows the "Overview" section. Sections for objects have the following structure:
The "Object Summary" section is divided into three parts: "Synopsis," "Data Flow Diagram," and "Methods." Each object that is offered by a package has its own "Object Summary" section, which starts with a detailed description of the functionality of the object. Read this section if you want to understand more about the inner workings of an object (for example, to find out mathematical techniques that an object uses internally). This section also includes a table that summarizes all the available object methods along with a brief description of their functionalities. Refer to this table to quickly determine how to control the behavior of an object. You can also search for the methods that are prefixed with "Set" and "Get." In addition, if the object is a collector, this section provides a table that describes the corresponding table schema that the object generates. The table schema description includes the name, SAS data type, and a brief description of each table column.
The "Synopsis" section shows how you can declare an instance of the object in your custom SAS code. This section describes the correct sequence of method calls (when a particular sequence is required) and indicates which method arguments are optional or mandatory. For example, for the FORENG object in the ATSM package, you provide forecast data to the FORENG object via its Initialize method, optionally set the forecast lead via the SetOption method, then run the forecast via its Run method, and optionally retrieve a forecast series via the GetForecast method. The "Synopsis" section also optionally offers a data flow diagram of the object that depicts the flow of data into and out of the object via its methods and the relevant data types that are required as arguments by each method. This diagram provides you with a visual overview of how to interact with the object from your program.
The "Methods" section provides a detailed description of the object’s methods. A subsection for each method includes its functionality and arguments. Method arguments are divided into either input or output arguments. Input arguments are not modified by a method internally. Output arguments can be modified by a method internally. The size and value of an output argument after the execution of a method might differ from its original size and value before the method call, but the data type always remains the same. The description of each argument also lists the SAS data types that are acceptable for that argument. Each method argument can accept one or more SAS data types.
The "Examples" section follows the detailed description of all the package’s objects. This section includes various examples that depict how the various objects provided by the package interact with each other and how they interact with objects in other packages to solve problems. These examples generally use almost all methods in each object and can provide a good starting point for your own custom implementations.
The "References" section contains references for the methodology and for examples of the procedure.