Tutorial by Examples: ti

Matplotlib axes are two-dimensional by default. In order to create three-dimensional plots, we need to import the Axes3D class from the mplot3d toolkit, that will enable a new kind of projection for an axes, namely '3d': import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D fi...

If you want two or more arguments to be mutually exclusive. You can use the function argparse.ArgumentParser.add_mutually_exclusive_group(). In the example below, either foo or bar can exist but not both at the same time. import argparse parser = argparse.ArgumentParser() group = parser.add_mut...

Create a DataFrame from multiple lists by passing a dict whose values lists. The keys of the dictionary are used as column labels. The lists can also be ndarrays. The lists/ndarrays must all be the same length. import pandas as pd # Create DF from dict of lists/ndarrays df = pd.DataFrame({'...

Only when the foreach statement moves to the next item does the iterator block evaluate up to the next yield statement. Consider the following example: private IEnumerable<int> Integers() { var i = 0; while(true) { Console.WriteLine("Inside iterator: " + i...

To modify an existing column in Rails with a migration, run the following command: rails g migration change_column_in_table This will create a new migration file in db/migration directory (if it doesn’t exist already), which will contain the file prefixed with timestamp and migration file name w...

In Python 3 the cmp built-in function was removed, together with the __cmp__ special method. From the documentation: The cmp() function should be treated as gone, and the __cmp__() special method is no longer supported. Use __lt__() for sorting, __eq__() with __hash__(), and other rich compariso...

Function level annotations help IDEs identify return values or potentially dangerous code /** * Adds two numbers together. * * @param Int $a First parameter to add * @param Int $b Second parameter to add * @return Int */ function sum($a, $b) { return (int) $a + $b; } /** * ...

If a class extends another class and would use the same metadata, providing it @inheritDoc is a simple way for use the same documentation. If multiple classes inherit from a base, only the base would need to be changed for the children to be affected. abstract class FooBase { /** * @par...

Let's use *norm as an example. From the documentation: dnorm(x, mean = 0, sd = 1, log = FALSE) pnorm(q, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE) qnorm(p, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE) rnorm(n, mean = 0, sd = 1) So if I wanted to know the value of a standard no...

# load the library library(ggplot2) # create a blank canvas g <- ggplot(data = diamonds) g + geom_bar(aes(x = cut, fill = cut)) + scale_fill_discrete(guide = guide_legend(title = "CUT", keywidth = 2, ...

In order to enable a multidex configuration you need: to change your Gradle build configuration to use a MultiDexApplication or enable the MultiDex in your Application class Gradle configuration In app/build.gradle add these parts: android { compileSdkVersion 24 buildToolsVersion ...

The dexcount plugin counts methods and class resource count after a successful build. Add the plugin in the app/build.gradle: apply plugin: 'com.android.application' buildscript { repositories { mavenCentral() // or jcenter() } dependencies { classpath 'com.ge...

C++11 introduced final specifier which forbids method overriding if appeared in method signature: class Base { public: virtual void foo() { std::cout << "Base::Foo\n"; } }; class Derived1 : public Base { public: // Overriding Base::foo void foo() f...

Detailed instructions on getting android-activity set up or installed.

First define the circle radius and its center: var radius:Number = 100; var center:Point = new Point(35, 70); Then generate a random angle in radians from the center: var angle:Number = Math.random() * Math.PI * 2; Then generate an effective radius of the returned point, so it'll be inside ...

If you need to roll for a true or false in an "x% chance" situation, use: function roll(chance:Number):Boolean { return Math.random() >= chance; } Used like: var success:Boolean = roll(0.5); // True 50% of the time. var again:Boolean = roll(0.25); // True 25% of the time. ...

To get started with Thymeleaf visit official download page. Maven dependency <dependency> <groupId>org.thymeleaf</groupId> <artifactId>thymeleaf</artifactId> <version>3.0.1.RELEASE</version> </dependency> Gradle dependency compile gr...

The first step in optimizing for speed is finding the slowest sections of code. The Timer VBA function returns the number of seconds elapsed since midnight with a precision of 1/256th of a second (3.90625 milliseconds) on Windows based PCs. The VBA functions Now and Time are only accurate to a secon...

std::sort, found in the standard library header algorithm, is a standard library algorithm for sorting a range of values, defined by a pair of iterators. std::sort takes as the last parameter a functor used to compare two values; this is how it determines the order. Note that std::sort is not stable...

A series is a one-dimension data structure. It's a bit like a supercharged array, or a dictionary. import pandas as pd s = pd.Series([10, 20, 30]) >>> s 0 10 1 20 2 30 dtype: int64 Every value in a series has an index. By default, the indices are integers, running fro...