Tutorial by Examples: r

Detailed instructions on getting azure-documentdb set up or installed.
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...
#include <gtk/gtk.h> static void destroy(GtkWidget *widget, gpointer data) { gtk_main_quit(); } int main(int argc, char *argv[]) { gtk_init(&argc, &argv); GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_window_set_title(GTK_WINDOW(window), "Window"); g_...
The DirectX SDK is included within the Windows SDK, in all versions past Windows SDK v8. Normally, the Windows SDK is installed with Visual Studio (any version past Visual Studio 2012), however, it can be installed separately. Previously, the DirectX SDK was available as a separate installation, the...
In general, we tend to back up the DB with the pgAdmin client. The following is a sh script used to save the database (under linux) in two formats: SQL file: for a possible resume of data on any version of PostgreSQL. Dump file: for a higher version than the current version. #!/bin/sh...
Problem ConcurrentDictionary shines when it comes to instantly returning of existing keys from cache, mostly lock free, and contending on a granular level. But what if the object creation is really expensive, outweighing the cost of context switching, and some cache misses occur? If the same key ...
int x, y; bool ready = false; void init() { x = 2; y = 3; ready = true; } void use() { if (ready) std::cout << x + y; } One thread calls the init() function while another thread (or signal handler) calls the use() function. One might expect that the use() function ...
One of the best features of async/await syntax is that standard try-catch coding style is possible, just like you were writing synchronous code. const myFunc = async (req, res) => { try { const result = await somePromise(); } catch (err) { // handle errors here } }); Here'...
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...
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...
Let's discuss with an example. From n items, in how many ways you can choose r items? You know it is denoted by . Now think of a single item. If you don't select the item, after that you have to take r items from remaining n-1 items, which is given by . If you select the item, after that you hav...
No matter how many problems you solve using dynamic programming(DP), it can still surprise you. But as everything else in life, practice makes you better. Keeping these in mind, we'll look at the process of constructing a solution for DP problems. Other examples on this topic will help you understan...
This attribute used t identify a method that is called once to perform setup before any child tests are run. For the new versions we are using OneTimeSetUp as the TestFixtureSetUp is obsolete. OneTimeSetUp [OneTimeSetUp] public void SetUp() { }
This attribute is used to identify a method that is called immediately after each tests, it will be called even if there is any error, this is the place we can dispose our objects. [TearDown] public void CleanAfterEveryTest() { }
A secret gist should be used for anything that you don't want to appear publicly on GitHub. Secret gists can be used when you don't want private keys to be accessible to the public, or for and private code in general. A simple example of JSON code that would be better fit for a secret gist: { &qu...
Minimum Vertex Cover is a classic graph problem. Let's say, in a city we have a few roads connecting a few points. Let's represent the roads using edges and the points using nodes. Let's take two example graphs: We want to set watchmen on some points. A watchman can guard all the roads connected ...
Controller is an entry point to our application. However, it’s not the only possible entry point. I would like to have my logic accessible from: Rake tasks background jobs console tests If I throw my logic into a controller it won’t be accessible from all these places. So let’s try “skinny ...
since version 9.5 postgres offers UPSERT functionality with INSERT statement. Say you have a table called my_table, created in several previous examples. We insert a row, returning PK value of inserted row: b=# INSERT INTO my_table (name,contact_number) values ('one',333) RETURNING id; id ---- ...
Go to Tools -> Options. Go to Environment -> Keyboard -> Query Shortcuts On the right side you can see some shortcuts which are by default in SSMS. Now if you need to add a new one, just click on any column under Stored Procedure column. Click OK. Now please go to a query window and sel...
If you click on export icon, you will given options to choose like on which format you need to export the data. Just click on anything you wish. You can see that the data is being send to the server http://export.highcharts.com/ in the top left side. exporting: { chartOptions: { ...

Page 788 of 1016