dtmf meaning

The physical meaning of matrix and its transformation, eigenvalues and eigenvectorsRecently in the clustering of the use of PCA technology, which involves some of the matrix eigenvalues and eigenvectors of the content, on the Internet to find an article on the characteristics of the vector and its physical significance of the article, collation down, share.First, Matrix Foundation[1]：A matrix is an array that represents a two-dimensional space, and a

What is the meaning of a parameter in a method before it? For example, in this code publicfunctionupdate (Observable $ _ observable) {$ _ observable, what is the meaning of the Observable before, and what is the role of the novice for help! ------ Solution -------------------- it means that the final parameter must be an instance object of the Observable class. What is the

Beginners of discrete mathematics will certainly be confused about the meaning of disjunctive paradigm and combined paradigm. First of all, the use of its environment to analyze, the analysis paradigm has a little to think of the circuit or the door, the combined paradigm has a bit like the circuit and the door. And their truth-table is the exact same. We will wonder, how not to call "or take the Paradigm", "and take the Paradigm", this is not more cl

On the 25 th, I arrived at the school as I thought I had escaped. Then start a leisurely and lonely life until tonight. When I shut down my computer in the evening, I said to myself, what happened to the game? Everyone has a message and a reply. What If weibo has fans? What about Three Kingdoms? What if I talk to others on QQ? I remember the words written in my closed QQ space:No meaning unless awakened It is like the shining

The true meaning of android:layout_weight is that once the view has this property set (assuming it is valid), the view width is equal to the original width (android:layout_width) plus the amount of space remaining! Meaning: original width + remaining space ratioSet the screen width to L, the width of the two view is Match_parent, the original width is L, two of the view width is L, then the remaining width

Python core style: Avoid using underscores as the start of variable names.Because underscores have special meanings for the interpreter and are symbols used by built-in identifiers, we recommend that programmers avoid using underscores as the starting point for variable names. In general, variable name _xxx is considered " private "and cannot be used outside of a module or class. When a variable is private, it is good practice to use _xxx to represent variables. Because the variable name __xxx_

ANSI and Unicode encoding, TCHAR | LPSTR | LPCSTR | LPWSTR | LPCWSTR | LPTSTR | meaning of LPCTSTR, lpcstrlpwstr One character can be expressed in 1-byte, that is, ANSI encoding; A character can also be expressed in 2-bytes, that is, Unicode encoding (Unicode actually contains more content than 2-bytes ). Visual C ++ supports char and wchar_t as the original data types of ANSI and Unicode. For example char cResponse; // 'Y' or 'N'char sUsername[64];//

content to clipboardPHP Code:if ($a) {Include ("a.php");}and require () is different from include (), no matter what the value of $ A, the following code will include the file a.php into the file:Copy PHP content to clipboardPHP Code:if ($a) {Require ("a.php");}In the case of error handling, the include statement is used, and if an error occurs, the program skips the include statement, although an error message is displayed but the program continues! But Requre will give you a fatal error.Of co

Click to enter _ more _java thousand ask1, what is the meaning of 2 in the Java EE?The meaning of 2 in J2se,j2se,j2me is to be traced back to 1998 years.1998 Java 1.2 release, 1999 released the Java 1.2 Standard Edition, Enterprise Edition, mini version of the three versions, in order to differentiate these three versions, respectively, called Java2se,java2ee,java2me, referred to as J2SE,J2EE,J2ME. Therefor

/** 2, please explain the meaning of the characters ' \ ' in Java, what is the role?*Answer* In Java the backslash ' \ ' represents the meaning of the escape character, which is a marker** When the compiler reads this tag, it knows that the next character is not an ordinary character, but a translated character.* It will operate based on the meaning of the escape

PYTHON Specifies special variables/methods using underscores as variable prefixes and suffixes.There are four main cases1.1. Object # Public2. __object__ # Special, Python system use, user should not define like it3. __object # Private (name mangling during runtime)4. _object # Obey Coding Convention, consider it as privateCore style: Avoid using underscores as the start of variable names .Because underscores have special meanings for the interpreter and are symbols used by the built-in, we reco

;! function () {} (); ;! What's the use?Go from grammar to open. The semicolon in JavaScript indicates the end of the statement, plus at the beginning. It may be for compression and other methods to cut, indicating a new statement starts. So, let's say it's in a separate JS file. The beginning of the semicolon is no matter what the meaning, can be deleted.An exclamation point is a logical operator, which is "non", and is commonly written if (!true) {}

The meaning of the square operation of the adjacency matrix of a direction graph This is an assignment in the first chapter of graph theory algorithm application. Now, the linear algebra is too bad. Hey First code: #include The title requires the matrix to be written after the square of the adjacency matrix of the direction graph, then say the meaning of it, write code nearly one hours, want to

One, what is a single case mode? 1, meaningAs an object's creation pattern, the singleton pattern ensures that a class has only one instance, and instantiates it and provides it globally to the entire system. Instead of creating an instance copy, it returns a reference to an instance stored within a singleton class.2, the single example mode of the three points:(1). A static member variable is required to hold a unique instance of the class:private static $_instance;(2). Constructors and cloning

1 Preface In many foreign computer books and some of the third open source software demo often use two English words foo,bar. What the hell does that mean? From the IT life of the cock Silk circle simple These two words to now I still do not know the true meaning of these two words, today it is necessary to check the summary. 2 explanation on Wikipedia Original: The terms foobar, Foo, bar, Baz and Qux are sometimes, used as placeholder names (also

The purpose of forced type conversion in C language, the basic format, the essential meaning of variables in C, and the essence of Variables C forced type conversion Reading directory: 1. Purpose and basic format of forced type conversion Ii. Essential Meaning of variables in C Iii. Forced type conversion of common variables Iv. pointer variable type conversion 1. Purpose and basic format of forced type c

Call and apply the approximate use of the same, a simple look at the following example:We can call () and apply () as a method of an object, calling the function indirectly in the form of a calling method.That is, the method is the original method, but the parameter is the parameter of the object contained in call.The first parameter of the call function and the Apply method is the object to pass to the current object, and this inside the function. The arguments that follow are all arguments pas

The meaning of the four matching characters % indicates zero or multiple arbitrary characters. It indicates any character in the specified range []. Any single character [^] is not in the specified range. the character string must be enclosed in quotation marks, for example, the following example: LIKEBR % returns any string starting with BR. LIKEBr % returns The meaning of the four matching characters % i

Meaning: the transaction must have a very clear start and end point. Each data operation statement in SQL Server, such as SELECT, INSERT, UPDATE, and DELETE, is part of an implicit transaction. Even if there is only one statement, the system regards this statement as a transaction, either to execute all statements or to execute nothing. After the transaction starts, the firm Meaning: A transaction must have

From:http://www.jb51.net/article/71532.htm In JavaScript, Void is an operator that specifies that an expression is evaluated but does not return a value. I'd like to use Ajax for all the usual code like this: The code is as follows: But what is the meaning of void (0) here? The void operator uses the following format: 1. javascript:void (expression) 2. Javascript:void expression Expression is a standard of Javascript to evaluate. Parentheses on the o