Tutorial by Examples: p

On a 8 cores Linux machine using GCC version 4.4, the C codes can be compiled and run the following way: $ gcc -std=c99 -O3 -fopenmp loop.c -o loopc -lm $ OMP_NUM_THREADS=1 ./loopc Computing 1000000 cosines and summing them with 1 threads took 0.095832s $ OMP_NUM_THREADS=2 ./loopc Computing 100...

Let f(n) and g(n) be two functions defined on the set of the positive real numbers, c, c1, c2, n0 are positive real constants. Notationf(n) = O(g(n))f(n) = Ω(g(n))f(n) = Θ(g(n))f(n) = o(g(n))f(n) = ω(g(n))Formal definition∃ c > 0, ∃ n0 > 0 : ∀ n ≥ n0, 0 ≤ f(n) ≤ c g(n)∃ c > 0, ∃ n0 > 0 ...

The PHP community has a lot of developers creating lots of code. This means that one library’s PHP code may use the same class name as another library. When both libraries are used in the same namespace, they collide and cause trouble. Namespaces solve this problem. As described in the PHP referenc...

Python changed it's sorting methods to accept a key function. Those functions take a value and return a key which is used to sort the arrays. Old comparison functions used to take two values and return -1, 0 or +1 if the first argument is small, equal or greater than the second argument respectivel...

realloc is conceptually equivalent to malloc + memcpy + free on the other pointer. If the size of the space requested is zero, the behavior of realloc is implementation-defined. This is similar for all memory allocation functions that receive a size parameter of value 0. Such functions may in fact ...

The following MATLAB script shows how to define and call a basic function: myFun.m: function [out1] = myFun(arg0, arg1) out1 = arg0 + arg1; end terminal: >> res = myFun(10, 20) res = 30

The following MATLAB script shows how to return multiple outputs in a single function: myFun.m: function [out1, out2, out3] = myFun(arg0, arg1) out1 = arg0 + arg1; out2 = arg0 * arg1; out3 = arg0 - arg1; end terminal: >> [res1, res2, res3] = myFun(...

Expression trees represent code in a tree-like data structure, where each node is an expression Expression Trees enables dynamic modification of executable code, the execution of LINQ queries in various databases, and the creation of dynamic queries. You can compile and run code represented by expr...

to check if the given path exists path = '/home/john/temp' os.path.exists(path) #this returns false if path doesn't exist or if the path is a broken symbolic link

to check if the given path is a directory dirname = '/home/john/python' os.path.isdir(dirname) to check if the given path is a file filename = dirname + 'main.py' os.path.isfile(filename) to check if the given path is symbolic link symlink = dirname + 'some_sym_link' os.path.islink(symli...

A common use of member functions is for encapsulation, using an accessor (commonly known as a getter) and a mutator (commonly known as a setter) instead of accessing fields directly. class Encapsulator { int encapsulated; public: int get_encapsulated() const { return encapsulated; }...

When a base class provides a set of overloaded functions, and a derived class adds another overload to the set, this hides all of the overloads provided by the base class. struct HiddenBase { void f(int) { std::cout << "int" << std::endl; } void f(bool) { std::cout &...

All non-static member functions have a hidden parameter, a pointer to an instance of the class, named this; this parameter is silently inserted at the beginning of the parameter list, and handled entirely by the compiler. When a member of the class is accessed inside a member function, it is silent...

configuration EnableIISFeature { node localhost { WindowsFeature IIS { Ensure = “Present” Name = “Web-Server” } } } If you run this configuration in Powershell (EnableIISFeature), it will produce a localho...

Sometimes it can be useful to test your Powershell data files and iterate through the nodes and servers. Powershell 5 (WMF5) added this neat little feature for doing this called Import-PowerShellDataFile . Example: $data = Import-PowerShellDataFile -path .\MydataFile.psd1 $data.AllNodes

Before you can use a resource in a configuration, you must explicitly import it. Just having it installed on your computer, will not let you use the resource implicitly. Import a resource by using Import-DscResource . Example showing how to import the PSDesiredStateConfiguration resource and the F...

In classic ASP we can specify a for loop with the for keyword. With the for statement we need the next statement which will increment the counter. For i = 0 To 10 Response.Write("Index: " & i) Next The step keyword can be used to changed the how the next statement will modify...

Do while is very similar to for loop however this generally is used if our loop repetitions is unknown. Do While: 'Continues until i is greater than 10 Do While i <= 10 i = i + 1 Loop 'Or we can write it so the first loop always executes unconditionally: 'Ends after our first loop as...

#!/usr/bin/env python """ An annotated simple socket server example in python. WARNING: This example doesn't show a very important aspect of TCP - TCP doesn't preserve message boundaries. Please refer to http://blog.stephencleary.com/2009/04/message-framing.html before adaptin...

#!/usr/bin/env python """ An annotated simple socket client example in python. WARNING: This example doesn't show a very important aspect of TCP - TCP doesn't preserve message boundaries. Please refer to http://blog.stephencleary.com/2009/04/message-framing.html before adaptin...