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What are the differences between numpy arrays and matrices? Which one should I use?
... here. Instead of performing fewer checks, using matrix*matrix requires an extra function call. So the advantage of using matrix is purely syntactic, not better performance.
– unutbu
Sep 18 '17 at 20:44
...
How to clear stringstream? [duplicate]
...
Typically to 'reset' a stringstream you need to both reset the underlying sequence to an empty string with str and to clear any fail and eof flags with clear.
parser.str( std::string() );
parser.clear();
Typically what happens is that the first ...
sed fails with “unknown option to `s'” error [closed]
...variable contains them and the final command will be something like sed "s/string/path/to/something/g", containing way too many slashes.
Since sed can take any char as delimiter (without having to declare the new delimiter), you can try using another one that doesn't appear in your replacement stri...
ifstream 线程安全读文件 - C/C++ - 清泛网 - 专注C/C++及内核技术
...件函数 safeGetline：std::istream& safeGetline(std::istream& is, std::string& t){ t clear(); 使用std::streambuf 函数 safeGetline：
std::istream& safeGetline(std::istream& is, std::string& t)
{
t.clear();
//这比使用std::istream逐个读取它们要快。
//以...
Naming convention for unique constraint
...imary key doesn't get a sequence number since there can be only one. The 2-char alpha suffix meanings are:
PK: Primary Key
AK: Alternate Key
FK: Foreign Key
IX: IndeX
CK: ChecK
DF: DeFault
I generally want to group metadata/system catalog data by the controlling object rather than by object type...
Difference between Hashing a Password and Encrypting it
...sible, you apply the secure hash algorithm and you cannot get the original string back. The most you can do is to generate what's called "a collision", that is, finding a different string that provides the same hash. Cryptographically secure hash algorithms are designed to prevent the occurrence of ...
Efficiency of Java “Double Brace Initialization”?
...Just for reference, double brace initialization is the following:
List<String> list = new ArrayList<String>() {{
add("Hello");
add("World!");
}};
It looks like a "hidden" feature of Java, but it is just a rewrite of:
List<String> list = new ArrayList<String>() {
...
Is “double hashing” a password less secure than just hashing it once?
...len($input); $i++) {
$result += ord($input[$i]);
}
return (string) ($result % 256);
}
Now it should be pretty obvious what this hash function does. It sums together the ASCII values of each character of input, and then takes the modulo of that result with 256.
So let's test it out:
...
What is the difference between up-casting and down-casting with respect to class variable
...og.
Police Dog - Police Dog extends Pet Dog.
public class Dog{
public String getType () {
System.out.println("NormalDog");
return "NormalDog";
}
}
/**
* Pet Dog has an extra method dogName()
*/
public class PetDog extends Dog{
public String getType () {
System.ou...
How do you select a particular option in a SELECT element in jQuery?
... will match pieces of text; problematic if any of your option text is a substring of another option text.
– Ryan
Nov 3 '14 at 21:56
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