在 MATLAB 中创建定点对象

使用 fi 和 numerictype 创建定点数据

您可以使用 Fixed-Point Designer™ fi 对象创建定点数据。在 fi 构造函数中，您可以指定 numerictype 和 fimath 属性。每个 fi 对象都有关联的 numerictype 对象。numerictype 对象存储关于 fi 对象的信息，包括字长、小数长度和符号性。numerictype 对象相当于 Simulink^® 中的 fixdt 对象。

函数

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构造定点数值对象

`fi`	构造定点数值对象
`sfi`	Construct signed fixed-point numeric object
`ufi`	Construct unsigned fixed-point numeric object

定点数学设置

`fimath`	Set fixed-point math settings
`fixed.fimathLike`	Return `fimath` object like the input
`globalfimath`	Configure global fimath and return handle object
`removefimath`	Remove fimath object from `fi` object
`removeglobalfimathpref`	Remove global fimath preference
`resetglobalfimath`	Set global fimath to MATLAB factory default
`setfimath`	Attach `fimath` object to `fi` object

定点预设项

`fipref`	Set fixed-point preferences
`savefipref`	Save `fi` preferences for next MATLAB session
`isfipref`	Determine whether input is `fipref` object

`fi` 对象的属性

`lowerbound`	`fi` 对象范围的下界
`lsb`	`fi` 对象的最低有效位的定标，或 `quantizer` 对象的最低有效位的值
`range`	`fi` 或 `quantizer` 对象的数值范围
`upperbound`	`fi` 对象范围的上界
`sort`	Sort elements of real-valued `fi` object in ascending or descending order

对象和属性

`fixed.aggregateType`	Compute aggregate numerictype
`get`	Property values of object
`isequal`	Determine whether real-world values of two `fi` objects are equal, or determine whether properties of two `fimath`, `numerictype`, or `quantizer` objects are equal
`isequaln`	Determine equality of fixed-point arrays, treating NaN values as equal
`reset`	将对象重置为初始条件
`set`	Set or display property values for `quantizer` objects
`mat2str`	将矩阵转换为字符串
`tostring`	Convert `fi`, `fimath`, `numerictype`, or `quantizer` object to string

类

numerictype Construct an embedded.numerictype object describing fixed-point or floating-point data type

主题

构造定点数值对象

在 MATLAB 中创建定点数据
定点基础知识。
正在执行定点算术。
执行定点算术。
查看定点数据
代码示例中使用的 fi 对象显示设置。
Ways to Construct fi Objects
Creation of fi objects.
Fixed-Point Versus Built-in Integer Types
Differences between fixed-point data types and built-in integer data types in MATLAB^®.
fi 对象函数
直接对 fi 对象执行运算的函数。
fi Object Properties
Defines the fi object properties.

定点数学设置

fimath Object Construction
Creation of fimath objects.
fimath Object Properties
Properties and property settings associated with fimath objects.
fimath Properties Usage for Fixed-Point Arithmetic
Fixed-point arithmetic using fimath objects to control the results.
fimath for Sharing Arithmetic Rules
Using a fimath object to share modular arithmetic information among multiple fi objects.
fimath for Rounding and Overflow Modes
Order setting for overflow action and rounding method.
fimath ProductMode and SumMode
Differences among the different settings of the ProductMode and SumMode properties.
How Functions Use fimath
Functions that ignore or discard fimath.

定点预设项

Set fi Object Display Preferences Using fipref
Examples of using fipref objects to set display preferences for fi objects.
Data Type Override Preferences Using fipref
Data type override using the fipref object.
Underflow and Overflow Logging Using fipref
Examples of using fipref objects to set logging preferences for fi objects.

数值类型信息

numerictype Object Construction
Construction of numerictype objects.
numerictype Object Properties
Properties and property settings associated with numerictype objects.
numerictype of Fixed-Point Objects
Fields and settings for the numerictype object.
numerictype Objects Usage to Share Data Type and Scaling Settings of fi objects
Example of using a numerictype object to share modular data type and scaling information among multiple fi objects.

应用领域

Fixed-Point Design Exploration in Parallel
This example shows how to explore and test fixed-point designs by distributing tests across many computers in parallel.
Real-Time Image Acquisition, Image Processing, and Fixed-Point Blob Analysis for Target Practice Analysis
Acquire real-time images from a webcam, process the images using fixed-point blob analysis, and determine world coordinates to score target practice using a laser pistol.
Fixed-Point Filter Design in MATLAB (DSP System Toolbox)
Design filters for use with fixed-point input.