Simulink.Parameter
Property Dialog BoxCreate a Simulink.Parameter
object to set the value of one or more block
parameters in a model, such as the Gain parameter of a
Gain block. For examples and programmatic information, see Simulink.Parameter
.
Ideal real-world value that the object stores. Block parameters that refer to the object use the value that you specify.
You can also use MATLAB® syntax to specify the value.
Example Expression | Description |
---|---|
15.23 |
Specifies a scalar value |
[3 4; 9 8] |
Specifies a matrix |
3+2i |
Specifies a complex value |
struct('A',20,'B',5) |
Specifies a structure with two fields,
Organize block parameters into structures (see Organize Related Block Parameter Definitions in Structures) or initialize the signal elements in a bus (see Specify Initial Conditions for Bus Signals). |
=myVar + myOtherVar | Specifies the expression myVar + myOtherVar where
myVar and
myOtherVar are other MATLAB variables or parameter objects.
Simulink®
Coder™ preserves this mathematical relationship
between the object and the variables. |
To use a Simulink.Parameter
object to store a value of a particular
numeric data type, specify the ideal value with the
Value property and control the type with the
Data type property.
If you set the Value property by using a typed expression such as
single(32.5)
, the Data type
property changes to reflect the new type. A best practice is to use an
expression that is not typed to avoid accumulating numerical error through
repeated quantizations or data type saturation, especially for fixed-point
data types.
When you specify an array with three or more dimensions, the
Value property displays the array as an expression
that contains a call to the reshape
function. To edit
the values in the array, modify the first argument of the
reshape
call, which contains all of the array
values in a serialized vector. When you add or remove elements along a
dimension, you must also correct the argument that represents the length of
the modified dimension.
To more easily edit a large vector, 2-D matrix, or structure that you store in a
Simulink.Parameter
object, consider using the
Variable Editor. See Manage and Edit Workspace Variables.
Data type of the parameter value in the Value
property, specified as 'auto'
or a character vector. When
you simulate the model or generate code, Simulink casts the value to the specified data type.
If you select auto
, the default setting, the
parameter object uses the same data type as the block parameters that use
the object. See Reduce Maintenance Effort with Data Type Inheritance.
When you set the Value property to something other
than a double
number, the object typically sets the
Data type property based on the value of the
Value property. For example, when you set the
Value property to int8(5)
, the
object sets the value of the Data type property to
int8
.
You can select a data type from the drop-down list or specify the name of a data type with text.
To explicitly specify a built-in data type (see Data Types Supported by Simulink), use one of these options:
double
single
half
int8
uint8
int16
uint16
int32
uint32
boolean
To specify a fixed-point data type, use the fixdt
function. For
example, specify fixdt(1,16,5)
.
If you use a Simulink.AliasType
or
Simulink.NumericType
object
to create and share custom data types in your model, specify the name of the
object.
To specify an enumerated data type, use the name of the type preceded by
Enum:
. For example, specify Enum:
myEnumType
.
When you store a structure or array of structures in the
Value property of the object, the object sets the
Data type property to
struct
. To specify a Simulink.Bus
object as the data type, use the name of the bus
object preceded by Bus:
. For example, specify
Bus: myBusObject
.
Click the Show data type assistant button
to display the Data Type
Assistant, which helps you set the Data
type parameter. For more information, see Specify Data Types Using Data Type Assistant.
Dimensions of the parameter value.
When you set the Value property of the object, the
object sets the value of the Dimensions property to a
double
row vector. The vector is the same vector that
the size
function
returns.
To use symbolic dimensions, see Implement Dimension Variants for Array Sizes in Generated Code (Embedded Coder).
Numeric complexity of the parameter value. Simulink determines the complexity from the parameter value that you specify in the Value property. This property is read only.
Minimum value that the parameter can have. The default value is empty,
which means the parameter value does not have a minimum. Specify a real
double
scalar.
If you store a complex number in the Value property, the Minimum property applies separately to the real and imaginary parts.
If you store a structure in the Value property, the
object ignores the Minimum property. Instead, use a
Simulink.Bus
object as the data type
of the parameter object and specify a minimum value for each field by using
the elements of the bus object. See Control Field Data Types and Characteristics by Creating Parameter Object.
If Value is less than the minimum value or if the minimum value is outside the range of the object data type, Simulink generates a warning. When updating the diagram or starting a simulation, Simulink generates an error.
For more information about how Simulink uses this property, see Specify Minimum and Maximum Values for Block Parameters.
Maximum value that the parameter can have. The default value is empty,
which means the parameter value does not have a maximum. Specify a real
double
scalar.
If you store a complex number in the Value property, the Maximum property applies separately to the real and imaginary parts.
If you store a structure in the Value property, the
object ignores the Maximum property. Instead, use a
Simulink.Bus
object as the data type
of the parameter object and specify a maximum value for each field by using
the elements of the bus object. See Control Field Data Types and Characteristics by Creating Parameter Object.
If Value is greater than the maximum value or if the maximum value is outside the range of the object data type, Simulink generates a warning. When updating the diagram or starting a simulation, Simulink generates an error.
For more information about how Simulink uses this property, see Specify Minimum and Maximum Values for Block Parameters.
For parameter objects with a fixed-point data type, the minimum value that the parameter can have, specified as a stored integer value. The value is derived from the real-world value Minimum. This property is available only in the property dialog box.
For parameter objects with a fixed-point data type, the maximum value that the parameter can have, specified as a stored integer value. The value is derived from the real-world value Maximum. This property is available only in the property dialog box.
Physical unit in which this value is expressed (for example, inches). To specify a unit, begin typing in the text box. As you type, the parameter displays potential unit string matches. For more information, see Unit Specification in Simulink Models.
Storage class of this parameter object. Simulink code generation toolboxes use this property to allocate memory for this parameter object in the generated code.
For more information, see C Code Generation Configuration for Model Interface Elements (Simulink Coder) and Choose Storage Class for Controlling Data Representation in Generated Code (Embedded Coder).
Alternative name for this parameter in the generated code.
Data alignment boundary for code generation, specified in number of bytes.
The starting memory address for the data allocated for the parameter is a
multiple of the Alignment setting. The default value is
-1
, which specifies that the code generator determine
an optimal alignment based on usage. Otherwise, specify a positive integer
that is a power of 2, not exceeding 128. For more information, see Data Alignment for Code Replacement (Embedded Coder).
Specification to configure the parameter object as a model argument (see Parameterize Instances of a Reusable Referenced Model). This property appears only if the parameter object is in a model workspace.
Custom description of this parameter object. Use this property to document the significance that the parameter object has in your algorithm.
If you have an Embedded Coder® license, you can configure this description to appear in the generated code as a comment. See Simulink data object descriptions (Embedded Coder).