After you create a System object™, you use various object
methods to process data or obtain information from or about the object.
All methods that are applicable to an object are described in the
reference pages for that object. System object method names begin
with a lowercase letter and class and property names begin with an
uppercase letter. The syntax for using methods is
step(H), plus possible extra input arguments.
System objects use a minimum of two commands to process data—a constructor to create the object and the step method to run data through the object. This separation of declaration from execution lets you create multiple, persistent, reusable objects, each with different settings. Using this approach avoids repeated input validation and verification, allows for easy use within a programming loop, and improves overall performance. In contrast, MATLAB® functions must validate parameters every time you call the function.
These advantages make System objects particularly well suited for processing streaming data, where segments of a continuous data stream are processed iteratively. This ability to process streaming data provides the advantage of not having to hold large amounts of data in memory. Use of streaming data also allows you to use simplified programs that use loops efficiently.
step method is the key System object method.
step to process data using the algorithm
defined by that object. The
step method performs
other important tasks related to data processing, such as initialization
and handling object states. Every System object has its own customized
which is described in detail on the
page for that object. For more information about the step method and
other available methods, see the descriptions in Common Methods.
All System objects support the following methods, each of which is described in a method reference page associated with the particular object. In cases where a method is not applicable to a particular object, calling that method has no effect on the object.
Processes data using the algorithm defined by the
object. As part of this processing, it initializes needed resources,
returns outputs, and updates the object states. After you call the
Releases any special resources allocated by the
object, such as file handles and device drivers, and unlocks the object.
For System objects, use the
|Resets the internal states of a locked object to the initial values for that object and leaves the object locked|
|Returns the number of inputs (excluding the object itself)
expected by the |
|Returns the number of outputs expected from the |
|Returns the discrete states of the object
in a structure. If the object is unlocked (when the object is first
created and before you have run the |
|Creates another object of the same type with the same property values|
|Returns a logical value indicating whether the object is locked.|
|Applies to source objects only. Returns a logical value
indicating whether the step method has reached the end of the data
file. If a particular object does not have end-of-data capability,
this method value returns |
|Returns a structure containing characteristic information about the object. The fields of this structure vary depending on the object. If a particular object does not have characteristic information, the structure is empty.|
For a complete list of methods for writing new System objects, see System Objects Methods for Defining New Objects.