Tutorial by Examples: e

If realloc fails, it returns NULL. If you assign the value of the original buffer to realloc's return value, and if it returns NULL, then the original buffer (the old pointer) is lost, resulting in a memory leak. The solution is to copy into a temporary pointer, and if that temporary is not NULL, th...

Detailed instructions on getting asp.net-mvc-4 set up or installed.

To get the size of a communicator (e.g. MPI_COMM_WORLD) and the local process' rank inside it: int rank, size; int res; MPI_Comm communicator = MPI_COMM_WORLD; res = MPI_Comm_rank (communicator, &rank); if (res != MPI_SUCCESS) { fprintf (stderr, "MPI_Comm_rank failed\n"); ...

Before any MPI commands can be run, the environment needs to be initialized, and finalized in the end: int main(int argc, char** argv) { int res; res = MPI_Init(&argc,&argv); if (res != MPI_SUCCESS) { fprintf (stderr, "MPI_Init failed\n"); exit (...

Floating point types (float, double and long double) cannot precisely represent some numbers because they have finite precision and represent the values in a binary format. Just like we have repeating decimals in base 10 for fractions such as 1/3, there are fractions that cannot be represented fini...

PREPARE prepares a statement for execution EXECUTE executes a prepared statement DEALLOCATE PREPARE releases a prepared statement SET @s = 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse'; PREPARE stmt2 FROM @s; SET @a = 6; SET @b = 8; EXECUTE stmt2 USING @a, @b; Result: +------------+ |...

You can get the value of an entry in the dictionary using the 'Item' property: Dim extensions As New Dictionary(Of String, String) From { { "txt", "notepad" }, { "bmp", "paint" }, { "doc", "winword" } } Dim program As St...

WebGL is a browser technology so there isn't much to set up other than to have a browser. You can get started with WebGL on JSFiddle or Codepen or JSBIn or any number of other sites that let you edit HTML, CSS, and JavaScript online though there will be a few limitations (see below). You can also ho...

Two terms may be compared via the standard ordering: variables @< numbers @< atoms @< strings @< structures @< lists Notes: Structures compare alphabetically by functor first, then by arity and lastly by the comparison of each argument. Lists compare by length first, t...

Equality operatorSucceeds ifX = YX can be unified with YX \= YX cannot be unified with YX == YX and Y are identical (i.e. they unify with no variable bindings occurring)X \== YX and Y are not identicalX =:= YX and Y are arithmetically equalX =\= YX and Y are not arithmetically equal

The pickle module implements an algorithm for turning an arbitrary Python object into a series of bytes. This process is also called serializing the object. The byte stream representing the object can then be transmitted or stored, and later reconstructed to create a new object with the same charact...

Mutex locking in Go allows you to ensure that only one goroutine at a time has a lock: import "sync" func mutexTest() { lock := sync.Mutex{} go func(m *sync.Mutex) { m.Lock() defer m.Unlock() // Automatically unlock when this function returns // D...

Using the calendar module import calendar from datetime import date def monthdelta(date, delta): m, y = (date.month+delta) % 12, date.year + ((date.month)+delta-1) // 12 if not m: m = 12 d = min(date.day, calendar.monthrange(y, m)[1]) return date.replace(day=d,month=m, year=...

#include <stdlib.h> #include <stdio.h> int main(void) { result = EXIT_SUCCESS; char file_name[] = "outbut.bin"; char str[] = "This is a binary file example"; FILE * fp = fopen(file_name, "wb"); if (fp == NULL) /* If an erro...

To install v6.x update the packages curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - Using the apt package manager sudo apt-get install -y nodejs

Download driver via nuget. Using this command in the package manager console Install-Package mongocsharpdriver

#include <stdio.h> #include <stdlib.h> int main (void) { int * pdata; size_t n; printf ("Enter the size of the array: "); fflush(stdout); /* Make sure the prompt gets printed to buffered stdout. */ if (1 != scanf("%zu", &n)) /* If zu is n...

Vectors in R can have different types (e.g. integer, logical, character). The most general way of defining a vector is by using the function vector(). vector('integer',2) # creates a vector of integers of size 2. vector('character',2) # creates a vector of characters of size 2. vector('logical',2...

Detailed instructions on getting pymongo set up or installed. Installing with Pip To install pymongo for the first time: pip install pymongo Installing a specific version of pymongo: Where X.X.X is the version to be installed pip install pymongo==X.X.X Upgrading existing pymon...

Stanford CoreNLP is a popular Natural Language Processing toolkit supporting many core NLP tasks. To download and install the program, either download a release package and include the necessary *.jar files in your classpath, or add the dependency off of Maven central. See the download page for mor...