Tutorial by Examples: le

UIViewController scanning for QR and displaying video input

import AVFoundation class QRScannerViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate { func viewDidLoad() { self.initCaptureSession() } private func initCaptureSession() { let captureDevice = AVCaptureDevice .defa...

iOS • QR Code Scanner

See examples under Disposable objects

Basic concept of IDisposable

Visual Basic .NET Language • Using Statement

0-1 Knapsack Problem

Suppose you are asked, given the total weight you can carry on your knapsack and some items with their weight and values, how can you take those items in such a way that the sum of their values are maximum, but the sum of their weights don't exceed the total weight you can carry? The 0-1 indicates e...

dynamic-programming • Knapsack Problem

Fence example

The example above can also be implemented with fences and relaxed atomic operations: int x, y; std::atomic<bool> ready{false}; void init() { x = 2; y = 3; atomic_thread_fence(std::memory_order_release); ready.store(true, std::memory_order_relaxed); } void use() { if (re...

C++ • C++11 Memory Model

Create a custom calendar

Here is how to create a custom calendar. The example given is a french calendar -- so it provides many examples. from pandas.tseries.holiday import AbstractHolidayCalendar, Holiday, EasterMonday, Easter from pandas.tseries.offsets import Day, CustomBusinessDay class FrBusinessCalendar(AbstractH...

pandas • Holiday Calendars

Use a custom calendar

Here is how to use the custom calendar. Get the holidays between two dates import pandas as pd from datetime import date # Creating some boundaries year = 2016 start = date(year, 1, 1) end = start + pd.offsets.MonthEnd(12) # Creating a custom calendar cal = FrBusinessCalendar() # Getti...

pandas • Holiday Calendars

COALESCE ()

COALESCE () Evaluates the arguments in order and returns the current value of the first expression that initially does not evaluate to NULL. DECLARE @MyInt int -- variable is null until it is set with value. DECLARE @MyInt2 int -- variable is null until it is set with value. DECLARE @MyInt3 int -...

Microsoft SQL Server • NULLs

Connect to Server, Create Table, Query Data

Install the package: $ pip install pymssql import pymssql SERVER = "servername" USER = "username" PASSWORD = "password" DATABASE = "dbname" connection = pymssql.connect(server=SERVER, user=USER, password=PASSWORD, database=DATABASE...

Python Language • Connecting Python to SQL Server

Read text file with comma delimiter

DATA table-name; INFILE "file-path/file-name.csv" dsd; INPUT Name $ City $ Age; RUN;

sas • Reading Data

The Basics (Tables and Inline CSS)

Tables for Layout The structure of an HTML email file is similar to that of a web page: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Hello!</title> </head> <body> &...

email • Getting started with email

Disable auto-scale in iOS 10 Mail

Apple iOS 10 Mail doesn't always auto-scale non-responsive emails. The auto-scale meta tag can be used to disable auto-scale feature in iOS 10 Mail entirely. <meta name="x-apple-disable-message-reformatting">

email • Meta Information

Using a TestScheduler to advance time manually

Most Rx operators take an optional scheduler on which to schedule their future iterations. If not supplied they will use their default configured scheduler. Supplying a scheduler can be useful for testing purposes in which we like to talk about virtual time instead of real time for speed of test exe...

rxjs • Scheduler

Self Referencing Employee Table

ms-access • Self-Referencing tables

Tuples within Collections

Tuples are often used within collections but they must be handled in a specific way. For example, given the following list of tuples: scala> val l = List(1 -> 2, 2 -> 3, 3 -> 4) l: List[(Int, Int)] = List((1,2), (2,3), (3,4)) It may seem natural to add the elements together using im...

Scala Language • Tuples

Create a quartz scheduler to display some information

In order to create a scheduler,the entry needs to be created in liferay-portlet.xml provding scheduler class and trigger value for timing of scheduler triggering <portlet-name>GetSetGo</portlet-name> <icon>/icon.png</icon> <scheduler-entry> ...

liferay • Create a Quartz scheduler in liferay

Read data from excel file

PROC IMPORT DATAFILE = "file-path/file-name.xlsx" OUT=data_set DBMS=XLSX REPLACE;

sas • Reading Data

Read a netCDF file (.nc) with python gdal

How to read a netCDF file (.nc) with python gdal ? import gdal # Path of netCDF file netcdf_fname = "/filepath/PREVIMER_WW3-GLOBAL-30MIN.nc" # Specify the layer name to read layer_name = "hs" # Open netcdf file.nc with gdal ds = gdal.Open("NETCDF:{0}:{1}".f...

gdal • Read a netCDF file with gdal

Get the properties of the file

If you want to get the properties of the file (like the name or the size) you can do it before using the File Reader. If we have the following html piece of code: <input type="file" id="newFile"> You can access the properties directly like this: document.getElementById...

JavaScript • File API, Blobs and FileReaders

viridis - print and colorblind friendly palettes

Viridis (named after the chromis viridis fish) is a recently developed color scheme for the Python library matplotlib (the video presentation by the link explains how the color scheme was developed and what are its main advantages). It is seamlessly ported to R. There are 4 variants of color scheme...

R Language • Color schemes for graphics

Optimizing Magento Changing The .htaccess File

Magento is a very popular eCommerce application. It offers a great deal of customization and abilities from initial install. Here are a few suggestions for optimizing a Magento installation. Enabling Output Compression In your .htaccess file for Magento you will find a section of text starting wit...

magento • Optimizing Magento For Speed