Tutorial by Examples: p

When data is "tidy," it is often organized into several tables. To combine the data for analysis, we need to "update" one table with values from another. For example, we might have sales data for performances, where attributes of the performer (their budget) and of the location ...

# example data set.seed(1) n = 1e7 ng = 1e4 DT = data.table( g1 = sample(ng, n, replace=TRUE), g2 = sample(ng, n, replace=TRUE), v = rnorm(n) ) Matching on one column After the first run of a subsetting operation with == or %in%... system.time( DT[ g1 %in% 1:100] )...

Tuples support the following build-in functions Comparison If elements are of the same type, python performs the comparison and returns the result. If elements are different types, it checks whether they are numbers. If numbers, perform comparison. If either element is a number, then the other...

Introduction The PHPUnit Manual describes mocking as such: The practice of replacing an object with a test double that verifies expectations, for instance asserting that a method has been called, is referred to as mocking. So instead of stubbing out code, an observer is created that not onl...

Batch file command line arguments are parameter values submitted when starting the batch. They should be enclosed in quotes if they contain spaces. In a running batch file, the arguments are used for various purposes, i.e. redirection to :labels, setting variables, or running commands. The argument...

Bottom sheets slide up from the bottom of the screen to reveal more content. They were added to the Android Support Library in v25.1.0 version and supports above all the versions. Make sure the following dependency is added to your app's build.gradle file under dependencies: compile 'com.android...

Assuming you have Eclipse IDE for Java Developers installed, start Eclipse, click "Help" -> "Install New Software..." Select "--All Available Sites--" at "Work with:", and navigate to "Eclipse Plugin Development Tools". Select "Eclipse Pl...

When multiple variables are defined at the beginning of the batch, a short definition form may be used by employing a replacement string. @echo off set "vars=_A=good,_B=,_E=bad,_F=,_G=ugly,_C=,_H=,_I=,_J=,_K=,_L=,_D=6 set "%vars:,=" & set "%" for /f %%l in ('set _'...

To manipulate colors we will modify the argb (Alpha, Red, Green and Blue) values of a color. First extract RGB values from your color. int yourColor = Color.parse("#ae1f67"); int red = Color.red(yourColor); int green = Color.green(yourColor); int blue = Color.blue(yourColor); Now...

A few pre-requisites in the build.gradle for vectors to work all the way down to API 7 for VectorDrawables and API 13 for AnimatedVectorDrawables (with some caveats currently): //Build Tools has to be 24+ buildToolsVersion '24.0.0' defaultConfig { vectorDrawables.useSupportLibrary = true ...

Get the current date and time. public class Program { static void Main() { // create empty pipeline PowerShell ps = PowerShell.Create(); // add command ps.AddCommand("Get-Date"); // run command(s) Console.WriteLine(&quot...

HTML email is the use of a subset of HTML and CSS to format an email message like a web page using colors, graphics, table columns and links. When you send an email it’s important to send both plain text and HTML. You do this by sending your email as multi-part MIME. Most email service providers ha...

(Caveat emptor: there are many, many programmers who go into absolute conniptions if they meet code that uses recordsets instead of commands and stored procedures.) <% dim rs, sql dim SelectedUser SelectedUser = request.form("user") if IsNumeric(SelectedUser) then SelectedUser...

You can do a permissions check when sending an Intent to a registered broadcast receiver. The permissions you send are cross-checked with the ones registered under the tag. They restrict who can send broadcasts to the associated receiver. To send a broadcast request with permissions, specify the p...

C++11 Note: in all the following, the existence of the C++11 constant nullptr is assumed. For earlier versions, replace nullptr with NULL, the constant that used to play a similar role. Creating a pointer variable A pointer variable can be created using the specific * syntax, e.g. int *pointer_...

$ mplayer Lecture_video_part1.mkv $ ^1^2^ mplayer Lecture_video_part2.mkv This command will replace 1 with 2 in the previously executed command. It will only replace the first occurrence of the string and is equivalent to !!:s/1/2/. If you want to replace all occurrences, you have to use !!:gs...

$ apt-get install r-base E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root? $ sudo !! sudo apt-get install r-base [sudo] password for <user>:

This is a TCP daytime client kept as simple as possible. #include <unistd.h> /* unix standard library */ #include <arpa/inet.h> /* IP addresses manipulation utilities */ #include <netinet/in.h> /* sockaddr_in structure definition */ #include <sys/socket.h> /* ber...

Sometimes conversion of primitive types to boxed types is necessary. To convert the array, it's possible to use streams (in Java 8 and above): Java SE 8 int[] primitiveArray = {1, 2, 3, 4}; Integer[] boxedArray = Arrays.stream(primitiveArray).boxed().toArray(Integer[]::new); With lowe...

When state_below is a 2D Tensor, U is a 2D weights matrix, b is a class_size-length vector: logits = tf.matmul(state_below, U) + b return tf.nn.softmax(logits) When state_below is a 3D tensor, U, b as before: def softmax_fn(current_input): logits = tf.matmul(current_input, U) + b ret...