- •Matlab r2013a стр. 225
- •Continue Long Statements on Multiple Lines
- •Creating and Concatenating Matrices
- •Overview
- •Constructing a Simple Matrix
- •Entering Signed Numbers
- •Specialized Matrix Functions
- •Examples
- •Concatenating Matrices
- •Keeping Matrices Rectangular
- •Matrix Concatenation Functions
- •Examples
- •Generating a Numeric Sequence
- •The Colon Operator
- •Using the Colon Operator with a Step Value
- •Matrix Indexing
- •Accessing Single Elements
- •Linear Indexing
- •Functions That Control Indexing Style
- •Accessing Multiple Elements
- •Nonconsecutive Elements
- •The end Keyword
- •Specifying All Elements of a Row or Column
- •Using Logicals in Array Indexing
- •Logical Indexing – Example 1
- •Logical Indexing – Example 2
- •Logical Indexing with a Smaller Array
- •Single-Colon Indexing with Different Array Types
- •Indexing on Assignment
- •Arithmetic Operators
- •Arithmetic Operators and Arrays
- •Operator Precedence
- •Precedence of and and or Operators
- •Overriding Default Precedence
- •Relational Operators and Arrays
- •Relational Operators and Empty Arrays
- •Overview of the Logical Class
- •Logical Operators
- •Element-Wise Operators and Functions
- •Short-Circuit Operators
- •Precedence of and and or Operators
- •Symbol Reference
- •Asterisk — *
- •Filename Wildcard
- •Function Handle Constructor
- •Class Folder Designator
- •Line Continuation
- •Dynamic Structure Fields
- •Exclamation Point — !
- •Semicolon — ;
- •Array Row Separator
- •Output Suppression
- •Command or Statement Separator
- •Single Quotes — ' '
- •Square Brackets — [ ]
- •Fundamental matlab Classes
- •More About
- •Overview of Numeric Classes
- •Integers
- •Integer Classes
- •Creating Integer Data
- •Arithmetic Operations on Integer Classes
- •Largest and Smallest Values for Integer Classes
- •Integer Functions
- •Floating-Point Numbers
- •Double-Precision Floating Point
- •Single-Precision Floating Point
- •Creating Floating-Point Data
- •Creating Double-Precision Data
- •Creating Single-Precision Data
- •Arithmetic Operations on Floating-Point Numbers
- •Double-Precision Operations
- •Single-Precision Operations
- •Largest and Smallest Values for Floating-Point Classes
- •Largest and Smallest Double-Precision Values
- •Largest and Smallest Single-Precision Values
- •Accuracy of Floating-Point Data
- •Double-Precision Accuracy
- •Single-Precision Accuracy
- •Avoiding Common Problems with Floating-Point Arithmetic
- •Example 1 — Round-Off or What You Get Is Not What You Expect
- •Example 2 — Catastrophic Cancellation
- •Example 3 — Floating-Point Operations and Linear Algebra
- •Floating-Point Functions
- •Creating a Rectangular Character Array
- •Combining Strings Vertically
- •Combining Strings Horizontally
- •Identifying Characters in a String
- •Working with Space Characters
- •Expanding Character Arrays
- •String Comparisons
- •Comparing Strings for Equality
- •Comparing for Equality Using Operators
- •Categorizing Characters Within a String
- •Create a Structure Array
- •Access Data in a Structure Array
- •Concatenate Structures
- •Generate Field Names from Variables
- •Access Data in Nested Structures
- •Access Elements of a Nonscalar Struct Array
- •Create a Cell Array
- •Access Data in a Cell Array
- •Add Cells to a Cell Array
- •Delete Data from a Cell Array
- •Combine Cell Arrays
- •Pass Contents of Cell Arrays to Functions
- •Multilevel Indexing to Access Parts of Cells
- •Related Examples
- •What Is a Function Handle?
- •Creating a Function Handle
- •Maximum Length of a Function Name
- •The Role of Scope, Precedence, and Overloading When Creating a Function Handle
- •Obtaining Permissions from Class Methods
- •Example
- •Using Function Handles for Anonymous Functions
- •Arrays of Function Handles
- •Calling a Function Using Its Handle
- •Calling Syntax
- •Calling a Function with Multiple Outputs
- •Returning a Handle for Use Outside of a Function File
- •Example — Using Function Handles in Optimization
- •Preserving Data from the Workspace
- •Preserving Data with Anonymous Functions
- •Preserving Data with Nested Functions
- •Loading a Saved Handle to a Nested Function
- •Applications of Function Handles
- •Example of Passing a Function Handle
- •Pass a Function to Another Function
- •Example 1 — Run integral on Varying Functions
- •Example 2 — Run integral on Anonymous Functions
- •Example 3 — Compare integral Results on Different Functions
- •Capture Data Values For Later Use By a Function
- •Example 1 — Constructing a Function Handle that Preserves Its Variables
- •Example 2 — Varying Data Values Stored in a Function Handle
- •Example 3 — You Cannot Vary Data in a Handle to an Anonymous Function
- •Call Functions Outside of Their Normal Scope
- •Save the Handle in a mat-File for Use in a Later matlab Session
- •Parameterizing Functions
- •Overview
- •Parameterizing Using Nested Functions
- •Parameterizing Using Anonymous Functions
- •See Also
- •More About
- •Saving and Loading Function Handles
- •Invalid or Obsolete Function Handles
- •Advanced Operations on Function Handles
- •Examining a Function Handle
- •Converting to and from a String
- •Converting a String to a Function Handle
- •Converting a Function Handle to a String
- •Comparing Function Handles
- •Comparing Handles Constructed from a Named Function
- •Comparing Handles to Anonymous Functions
- •Comparing Handles to Nested Functions
- •Comparing Handles Saved to a mat-File
- •Overview of the Map Data Structure
- •Description of the Map Class
- •Properties of the Map Class
- •Methods of the Map Class
- •Creating a Map Object
- •Constructing an Empty Map Object
- •Constructing An Initialized Map Object
- •Combining Map Objects
- •Examining the Contents of the Map
- •Reading and Writing Using a Key Index
- •Reading From the Map
- •Adding Key/Value Pairs
- •Building a Map with Concatenation
- •Modifying Keys and Values in Map
- •Removing Keys and Values from the Map
- •Modifying Values
- •Modifying Keys
- •Modifying a Copy of the Map
- •Mapping to Different Value Types
- •Mapping to a Structure Array
- •Mapping to a Cell Array
Indexing on Assignment
When assigning values from one matrix to another matrix, you can use any of the styles of indexing covered in this section. Matrix assignment statements also have the following requirement.
In the assignment A(J,K,...) = B(M,N,...), subscripts J, K, M, N, etc. may be scalar, vector, or array, provided that all of the following are true:
The number of subscripts specified for B, not including trailing subscripts equal to 1, does not exceed ndims(B) (число измерений для B).
The number of nonscalar subscripts specified for A equals the number of nonscalar subscripts specified for B. For example, A(5, 1:4, 1, 2) = B(5:8) is valid because both sides of the equation use one nonscalar subscript.
The order and length of all nonscalar subscripts specified for A matches the order and length of nonscalar subscripts specified for B. For example, A(1:4, 3, 3:9) = B(5:8, 1:7) is valid because both sides of the equation (ignoring the one scalar subscript 3) use a 4-element subscript followed by a 7-element subscript.
R2013a>MATLAB>Language Fundamentals>Operators and Elementary Operations>Arithmetic
Arithmetic Operators
Arithmetic operators perform numeric computations, for example, adding two numbers or raising the elements of an array to a given power. The following table provides a summary. For more information, see the arithmetic operators (R2013a>MATLAB>Language Fundamentals>Operators and Elementary Operations>Arithmetic) reference page.
|
Operator |
Description |
|
+ |
Addition |
|
- |
Subtraction |
|
.* |
Multiplication |
|
./ |
Right division |
|
.\ |
Left division |
|
+ |
Unary plus |
|
- |
Unary minus |
|
: |
Colon operator |
|
.^ |
Power |
|
.' |
Transpose |
|
' |
Complex conjugate transpose |
|
* |
Matrix multiplication |
|
/ |
Matrix right division |
|
\ |
Matrix left division |
|
^ |
Matrix power |
Arithmetic Operators and Arrays
Except for some matrix operators, MATLAB® arithmetic operators work on corresponding elements of arrays with equal dimensions. For vectors and rectangular arrays, both operands must be the same size unless one is a scalar. If one operand is a scalar and the other is not, MATLAB applies the scalar to every element of the other operand—this property is known as scalar expansion.
This example uses scalar expansion to compute the product of a scalar operand and a matrix.
A = magic(3)
A =
8 1 6
3 5 7
4 9 2
3 * A
ans =
24 3 18
9 15 21
12 27 6
R2013a>MATLAB>Language Fundamentals>Operators and Elementary Operations>Arithmetic
Operator Precedence
You can build expressions that use any combination of arithmetic, relational, and logical operators. Precedence levels determine the order in which MATLAB evaluates an expression. Within each precedence level, operators have equal precedence and are evaluated from left to right. The precedence rules for MATLAB operators are shown in this list, ordered from highest precedence level to lowest precedence level:
Parentheses ()
Transpose (.'), power (.^), complex conjugate transpose ('), matrix power (^)
Unary plus (+), unary minus (-), logical negation (~)
Multiplication (.*), right division (./), left division (.\), matrix multiplication (*), matrix right division (/), matrix left division (\)
Addition (+), subtraction (-)
Colon operator (:)
Less than (<), less than or equal to (<=), greater than (>), greater than or equal to (>=), equal to (==), not equal to (~=)
Element-wise AND (&)
Element-wise OR (|)
Short-circuit AND (&&)
Short-circuit OR (||)