Tutorial by Examples: u

A subprogram is said to be external when it is not contained in the main program, nor in a module or antoher subprogram. In particular it can be defined by means of a programming language other than Fortran. When an external subprogram is invoked, the compiler cannot access to its code, so all the ...

Most advanced user interfaces require the user to be able to pass information between the various functions which make up a user interface. MATLAB has a number of different methods to do so. guidata MATLAB's own GUI Development Environment (GUIDE) prefers to use a struct named handles to pass da...

Uncontrolled components are inputs that do not have a value property. In opposite to controlled components, it is the application's responsibility to keep the component state and the input value in sync. class Form extends React.Component { constructor(props) { super(props); th...

Floating-point numbers cannot represent all real numbers. This is known as floating point inaccuracy. There are infinitely many floating points numbers and they can be infinitely long (e.g. π), thus being able to represent them perfectly would require infinitely amount of memory. Seeing this was a ...

Steps to create Hello Spring: Investigate Spring Boot to see if that would better suit your needs. Have a project set up with the correct dependencies. It is recommended that you are using Maven or Gradle. create a POJO class, e.g. Employee.java create a XML file where you can define your clas...

for comprehensions in Scala are just syntactic sugar. These comprehensions are implemented using the withFilter, foreach, flatMap and map methods of their subject types. For this reason, only types that have these methods defined can be utilized in a for comprehension. A for comprehension of the fo...

To the average R user, the list structure may appear to be the one of the more complicated data structures to manipulate. There are no guarantees that all the elements within it are of the same type; There is no guaranteed structure of how complicated/non-complicated that the list would be (An eleme...

The r method implicitly provided via scala.collection.immutable.StringOps produces an instance of scala.util.matching.Regex from the subject string. Scala's triple-quoted string syntax is useful here, as you do not have to escape backslashes as you would in Java: val r0: Regex = """(...

When an exception is thrown from within a Future, you can (should) use recover to handle it. For instance, def runFuture: Future = Future { throw new FairlyStupidException } val itWillBeAwesome: Future = runFuture ...will throw an Exception from within the Future. But seeing as we can predic...

.message color: white .important background-color: red .message-important @extend .message, .important In the above code @extend is used in one line to add multiple classes' code to .message-important, however, it is possible to use one extend per line like this: .message-importan...

You can install ServiceStack in 3 ways: Complete Visual studio templates (Self hosted) Start from scratch run ServiceStack Self hosted (Console App) Run ServiceStack inside Asp.net MVC. Complete visual studio templates You can find info about these here: https://github.com/ServiceStack/Ser...

generate sample data frames: In [57]: df3 = pd.DataFrame({'col1':[211,212,213], 'col2': [221,222,223]}) In [58]: df1 = pd.DataFrame({'col1':[11,12,13], 'col2': [21,22,23]}) In [59]: df2 = pd.DataFrame({'col1':[111,112,113], 'col2': [121,122,123]}) In [60]: df3 = pd.DataFrame({'col1':[211,2...

import string import numpy as np import pandas as pd generate sample DF with various dtypes df = pd.DataFrame({ 'int32': np.random.randint(0, 10**6, 10), 'int64': np.random.randint(10**7, 10**9, 10).astype(np.int64)*10, 'float': np.random.rand(10), 'string': ...

import os, time import pyodbc import pandas.io.sql as pdsql def todf(dsn='yourdsn', uid=None, pwd=None, query=None, params=None): ''' if `query` is not an actual query but rather a path to a text file containing a query, read it in instead ''' if query.endswith('.sql') and o...

Natively, Jenkins runs on port 8080. We can establish a proxy from port 80 -> 8080 so Jenkins can be accessed via: http://<url>.com instead of the default http://<url>.com:8080 Begin by installing Nginx. sudo aptitude -y install nginx Remove the default settings for Nginx c...

Functions remember the lexical scope they where defined in. Because of this, we can enclose a lambda in a let to define closures. (defvar *counter* (let ((count 0)) (lambda () (incf count)))) (funcall *counter*) ;; => 1 (funcall *counter*) ;; = 2 In the example above,...

The pattern matching library trivia provides a system trivia.ppcre that allows captured groups to be bound through pattern matching (trivia:match "John Doe" ((trivia.ppcre:ppcre "(.*)\\W+(.*)" first-name last-name) (list :first-name first-name :last-name last-name))) ;...

The .indexOf method returns the index of a substring inside another string (if exists, or -1 if otherwise) 'Hellow World'.indexOf('Wor'); // 7 .indexOf also accepts an additional numeric argument that indicates on what index should the function start looking "harr dee harr dee harr&quot...

The ANSI CL standard uses an extended EBNF syntax notation. The documentation duplicated on Stackoverflow should use the same syntax notation to reduce confusion. Example: specialized-lambda-list::= ({var | (var parameter-specializer-name)}* [&optional {var | (var [initform [supp...

Given this object: var obj = { a: "hello", b: "this is", c: "javascript!", }; You can convert its values to an array by doing: var array = Object.keys(obj) .map(function(key) { return obj[key]; }); console.log(array); // [&quot...