Tutorial by Examples: ed

import matplotlib.pyplot as plt import numpy as np # generate 101 x and y values between -10 and 10 x = np.linspace(-10, 10, 101) y = np.linspace(-10, 10, 101) # make X and Y matrices representing x and y values of 2d plane X, Y = np.meshgrid(x, y) # compute z value of a point as a fun...

Some applications may want to create so-called "Fire & Forget" tasks which can be periodically triggered and do not need to return any type of value returned upon completion of the assigned task (for example, purging old temp files, rotating logs, autosaving state). In this example, w...

The Iris flower data set is a widely used data set for demonstration purposes. We will load it, inspect it and slightly modify it for later use. import java.io.File; import java.net.URL; import weka.core.Instances; import weka.core.converters.ArffSaver; import weka.core.converters.CSVLoader; i...

In order to build a good classifier we will often need to get an idea of how the data is structered in feature space. Weka offers a visualisation module that can help. Some dimensions already seperate the classes quite well. Petal-width orders the concept quite neatly, when compared to petal-widt...

It is often necessary to execute a long-running task and use the result of that task once it has completed. In this example, we will create two classes: One which implements the Callable<T> interface (where T is the type we wish to return), and one which contains a main() method. AsyncValueT...

Eventloop in pseudo code An event loop is a loop that waits for events and then reacts to those events while true: wait for something to happen react to whatever happened Example of a single-threaded HTTP server with no event loop while true: socket = wait for the next TCP c...

It is possible to create own Linux distribution using Yocto Project. For Raspberry Pi- there is a specific layer meta-raspberrypi that needs to be used to create an image.

To leverage distributed cache, you'll have to reference one of the available implementations : Redis Sql server For instance you'll register Redis implemention as follows : public void ConfigureServices(IServiceCollection services) { services.AddDistributedRedisCache(options => ...

Data mining is a wide topic, and the term is (unfortunately) very liberally thrown at any topic that involves data processing. Because of this this "documentation" should never have been created in the first place, because it overlaps with other topcis too much, and everything is better di...

In this example we will describe what happens when you scaffold a new project. First thing, the following dependencies will be added to you project (currently project.json file) : "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0", "Microsoft.Extensions.Co...

public String getHighlightedText(final QueryResponse queryResponse, final String fieldName, final String docId) { String highlightedText = ""; Map<String, Map<String, List<String>>> highlights = queryResponse.getHighlighting(); if (highlights!=null &&am...

Lets say you have a user schema, which contains name , contactNo, address, and friends. var UserSchema = new mongoose.Schema({ name : String, contactNo : Number, address : String, friends :[{ type: mongoose.Schema.Types.ObjectId, ref : User }] }); If y...

In T4 code-generation strategy used by Entity Framework 5 and higher, data annotation attributes are not included by default. To include data annotations on top of certain property every model regeneration, open template file included with EDMX (with .tt extension) then add a using statement under U...

private static void saveItem(List<EventTracker> items) { List<WriteRequest> wrList = new ArrayList<>(); try { for (EventTracker item : items) { WriteRequest wreqItem; wreqItem = getWriteRequest(item); wrList.add(wreqItem);...

If for some reason, the default PowerShell module repository PSGallery gets removed. You will need to create it. This is the command. Register-PSRepository -Default

To run the private registry (securely) you have to generate a self-signed certificate, you can refer to previous example to generate it. For my example I put server.key and server.crt into /root/certs Before run docker command you should be placed (use cd) into the directory that contains certs fo...

There are specific scenarios where in we might need to create a Quartz scheduler,based on user input on when a scheduler should be triggered,apart from we can handle cases,where we have certain pre-defined functionalities,which need to be triggered based on user action,at a certain period. This exa...

Bullet This one particularly blew my mind. The bullet gem helps you kill all the N+1 queries, as well as unnecessarily eager loaded relations. Once you install it and start visiting various routes in development, alert boxes with warnings indicating database queries that need to be optimized will p...

Query to search last executed sp's in db SELECT execquery.last_execution_time AS [Date Time], execsql.text AS [Script] FROM sys.dm_exec_query_stats AS execquery CROSS APPLY sys.dm_exec_sql_text(execquery.sql_handle) AS execsql ORDER BY execquery.last_execution_time DESC Query to search thro...

[DscResource()] class Ticket { [DscProperty(Key)] [string] $TicketId # The subject line of the ticket [DscProperty(Mandatory)] [string] $Subject # Get / Set if ticket should be open or closed [DscProperty(Mandatory)] [string] $TicketState [void] Set() { # Creat...