Tutorial by Examples: rom

Prerequisites sudo apt-get install build-essential sudo apt-get install python [optional] sudo apt-get install git Get source and build cd ~ git clone https://github.com/nodejs/node.git OR For the latest LTS Node.js version 6.10.2 cd ~ wget https://nodejs.org/dist/v6.3.0/node-v6.10....

List doesn't support "random access", which means it takes more work to get, say, the fifth element from the list than the first element, and as a result there's no List.get nth list function. One has to go all the way from the beginning (1 -> 2 -> 3 -> 4 -> 5). If you need ra...

letters = list('abcde') Select three letters randomly (with replacement - same item can be chosen multiple times): np.random.choice(letters, 3) ''' Out: array(['e', 'e', 'd'], dtype='<U1') ''' Sampling without replacement: np.random.choice(letters, 3, replace=False) ''' Out...

Draw samples from a normal (gaussian) distribution # Generate 5 random numbers from a standard normal distribution # (mean = 0, standard deviation = 1) np.random.randn(5) # Out: array([-0.84423086, 0.70564081, -0.39878617, -0.82719653, -0.4157447 ]) # This result can also be achieved with t...

When it comes to geographic data, R shows to be a powerful tool for data handling, analysis and visualisation. Often, spatial data is avaliable as an XY coordinate data set in tabular form. This example will show how to create a spatial data set from an XY data set. The packages rgdal and sp provi...

Who says you cannot throw multiple exceptions in one method. If you are not used to playing around with AggregateExceptions you may be tempted to create your own data-structure to represent many things going wrong. There are of course were another data-structure that is not an exception would be mor...

Visual Basic has Left, Right, and Mid functions that returns characters from the Left, Right, and Middle of a string. These methods does not exist in C#, but can be implemented with Substring(). They can be implemented as an extension methods like the following: public static class StringExtens...

Functions always establish a block around the body. This block has the same name as the function name. This means you can use RETURN-FROM with this block name to return from the function and return values. You should avoid returning early whenever possible. (defun foobar (x y) (when (oddp x) ...

The lubridate package provides convenient functions to format date and datetime objects from character strings. The functions are permutations of LetterElement to parseBase R equivalentyyear%y, %Ym (with y and d)month%m, %b, %h, %Bdday%d, %ehhour%H, %I%pm (with h and s)minute%Msseconds%S e.g. ymd(...

Fortran 2003 introduced language features which can guarantee interoperability between C and Fortran (and to more languages by using C as an intermediary). These features are mostly accessed through the intrinsic module iso_c_binding: use, intrinsic :: iso_c_binding The intrinsic keyword here en...

These examples assume that you already know what Java 7's NIO is in general, and you are used to writing code using java.io.File. Use these examples as a means to quickly find more NIO-centric documentation for migrating. There is much more to Java 7's NIO such as memory-mapped files or opening a Z...

.NET strings contain System.Char (UTF-16 code-units). If you want to save (or manage) text with another encoding you have to work with an array of System.Byte. Conversions are performed by classes derived from System.Text.Encoder and System.Text.Decoder which, together, can convert to/from another ...

Characteristics of properties : Properties that can be retrieved from an object could have the following characteristics, Enumerable Non - Enumerable own While creating the properties using Object.defineProperty(ies), we could set its characteristics except "own". Properties which...

Incorrect usage: In the following snippet, the last match will never be used: let x = 4 match x with | 1 -> printfn "x is 1" | _ -> printfn "x is anything that wasn't listed above" | 4 -> printfn "x is 4" prints x is anything that wasn't listed abov...

It is possible to create a QtQuick view directly from C++ and to expose to QML C++ defined properties. In the code below the C++ program creates a QtQuick view and exposes to QML the height and width of the view as properties. main.cpp #include <QApplication> #include <QQmlContext> #...

In Visual studio go to Tools > Extensions and updates... In the window that opens go to online Select Visual Studio Gallery You can search for an extension on the search box at the upper right corner Select the extension you want to add Click on download. Once download is complete, click...

Shortest match: $ a='I am a string' $ echo "${a#*a}" m a string Longest match: $ echo "${a##*a}" string

Shortest match: $ a='I am a string' $ echo "${a%a*}" I am Longest match: $ echo "${a%%a*}" I

In [15]: df = pd.DataFrame({"A":[1,1,2,3,1,1],"B":[5,4,3,4,6,7]}) In [21]: df Out[21]: A B 0 1 5 1 1 4 2 2 3 3 3 4 4 1 6 5 1 7 To get unique values in column A and B. In [22]: df["A"].unique() Out[22]: array([1, 2, 3]) In [23]: df[&qu...

It is possible to effectively apply a function (cb) which returns a promise to each element of an array, with each element waiting to be processed until the previous element is processed. function promiseForEach(arr, cb) { var i = 0; var nextPromise = function () { if (i >= arr.leng...