# Cheat Sheet Tidyr

Last week: Pipes and dplyr The tidyverse is a collection of packages for common data science tasks Tidyverse functionality is greatly enhanced using pipes (%% operator) Pipes allow you to string together commands to get a flow of results. Data Wrangling with dplyr and tidyr Cheat Sheet RStudio® is a trademark of RStudio, Inc. CC BY RStudio. [email protected] 844-448-1212. rstudio.com.

## 7.2`tidyr`

basics

Remember, from the ** dplyr** section, that tidy data means all rows are an observation and all columns are variables.

Why is this important? Well, if your data are formatted in a standard way, you will be able to use analysis tools that operate on that standard way. Your analyses will be streamlined and you won’t have to reinvent the wheel every time you see data in a different.

Let’s take a look at some examples.

Data are often entered in a *wide* format where each row is often a site/subject/patient and you have multiple observation variables containing the same type of data.

An example of data in a *wide* format is the `AirPassengers`

dataset which provides information on monthly airline passenger numbers from 1949-1960. You’ll notice that each row is a single year and the columns are each month Jan - Dec.

This format is intuitive for data entry, but less so for data analysis. If you wanted to calculate the monthly mean, where would you put it? As another row?

Often, data must be reshaped for it to become tidy data. What does that mean? There are four main verbs we’ll use, which are essentially pairs of opposites:

- turn columns into rows (
`gather()`

), - turn rows into columns (
`spread()`

), - turn a character column into multiple columns (
`separate()`

), - turn multiple character columns into a single column (
`unite()`

)

Complete List of Cheat Sheets and Infographics for Artificial intelligence (AI), Neural Networks, Machine Learning, Deep Learning and Big Data.

### Content Summary

Neural Networks

Neural Networks Graphs

Machine Learning Overview

Machine Learning: Scikit-learn algorithm

Scikit-Learn

Machine Learning: Algorithm Cheat Sheet

Python for Data Science

TensorFlow

Keras

Numpy

Pandas

Data Wrangling

Data Wrangling with dplyr and tidyr

Scipy

Matplotlib

Data Visualization

PySpark

Big-O

Resources

### Neural Networks

Artificial neural networks (ANN) or connectionist systems are computing systems vaguely inspired by the biological neural networks that constitute animal brains. The neural network itself is not an algorithm, but rather a framework for many different machine learning algorithms to work together and process complex data inputs. Such systems “learn” to perform tasks by considering examples, generally without being programmed with any task-specific rules.

### Neural Networks Graphs

Graph Neural Networks (GNNs) for representation learning of graphs broadly follow a neighborhood aggregation framework, where the representation vector of a node is computed by recursively aggregating and transforming feature vectors of its neighboring nodes. Windows server 2003 iso full. Many GNN variants have been proposed and have achieved state-of-the-art results on both node and graph classification tasks.

### Machine Learning Overview

Machine learning (ML) is the scientific study of algorithms and statistical models that computer systems use to progressively improve their performance on a specific task. Machine learning algorithms build a mathematical model of sample data, known as “training data”, in order to make predictions or decisions without being explicitly programmed to perform the task. Machine learning algorithms are used in the applications of email filtering, detection of network intruders, and computer vision, where it is infeasible to develop an algorithm of specific instructions for performing the task.

### Machine Learning: Scikit-learn algorithm

This machine learning cheat sheet will help you find the right estimator for the job which is the most difficult part. The flowchart will help you check the documentation and rough guide of each estimator that will help you to know more about the problems and how to solve it.

### Scikit-Learn

Scikit-learn (formerly scikits.learn) is a free software machine learning library for the Python programming language. It features various classification, regression and clustering algorithms including support vector machines, random forests, gradient boosting, k-means and DBSCAN, and is designed to interoperate with the Python numerical and scientific libraries NumPy and SciPy.

### Machine Learning: Algorithm Cheat Sheet

This machine learning cheat sheet from Microsoft Azure will help you choose the appropriate machine learning algorithms for your predictive analytics solution. First, the cheat sheet will asks you about the data nature and then suggests the best algorithm for the job.

### Python for Data Science

### TensorFlow

### Tidyr Cheat Sheet 2020

In May 2017 Google announced the second-generation of the TPU, as well as the availability of the TPUs in Google Compute Engine. The second-generation TPUs deliver up to 180 teraflops of performance, and when organized into clusters of 64 TPUs provide up to 11.5 petaflops.

### Keras

In 2017, Google’s TensorFlow team decided to support Keras in TensorFlow’s core library. Chollet explained that Keras was conceived to be an interface rather than an end-to-end machine-learning framework. It presents a higher-level, more intuitive set of abstractions that make it easy to configure neural networks regardless of the backend scientific computing library.

### Numpy

NumPy targets the CPython reference implementation of Python, which is a non-optimizing bytecode interpreter. Mathematical algorithms written for this version of Python often run much slower than compiled equivalents. NumPy address the slowness problem partly by providing multidimensional arrays and functions and operators that operate efficiently on arrays, requiring rewriting some code, mostly inner loops using NumPy.

### Pandas

The name ‘Pandas’ is derived from the term “panel data”, an econometrics term for multidimensional structured data sets.

### Data Wrangling

The term “data wrangler” is starting to infiltrate pop culture. In the 2017 movie Kong: Skull Island, one of the characters, played by actor Marc Evan Jackson is introduced as “Steve Woodward, our data wrangler”.

### Data Wrangling with dplyr and tidyr

### Scipy

SciPy builds on the NumPy array object and is part of the NumPy stack which includes tools like Matplotlib, pandas and SymPy, and an expanding set of scientific computing libraries. This NumPy stack has similar users to other applications such as MATLAB, GNU Octave, and Scilab. The NumPy stack is also sometimes referred to as the SciPy stack.

### Tidyverse Cheat Sheet Pdf

### Matplotlib

matplotlib is a plotting library for the Python programming language and its numerical mathematics extension NumPy. It provides an object-oriented API for embedding plots into applications using general-purpose GUI toolkits like Tkinter, wxPython, Qt, or GTK+. There is also a procedural “pylab” interface based on a state machine (like OpenGL), designed to closely resemble that of MATLAB, though its use is discouraged. SciPy makes use of matplotlib. pyplot is a matplotlib module which provides a MATLAB-like interface. matplotlib is designed to be as usable as MATLAB, with the ability to use Python, with the advantage that it is free.

### Data Visualization

### PySpark

### Big-O

### R Dplyr Cheat Sheet

Big O notation is a mathematical notation that describes the limiting behavior of a function when the argument tends towards a particular value or infinity. It is a member of a family of notations invented by Paul Bachmann, Edmund Landau and others, collectively called Bachmann–Landau notation or asymptotic notation.

### Resources

Big-O Algorithm Cheat Sheet

Bokeh Cheat Sheet

Data Science Cheat Sheet

Data Wrangling Cheat Sheet

Data Wrangling

Ggplot Cheat Sheet

Keras Cheat Sheet

Keras

Machine Learning Cheat Sheet

Machine Learning Cheat Sheet

ML Cheat Sheet

Matplotlib Cheat Sheet

Matpotlib

Neural Networks Cheat Sheet

Neural Networks Graph Cheat Sheet

Neural Networks

Numpy Cheat Sheet

NumPy

Pandas Cheat Sheet

Pandas

Pandas Cheat Sheet

Pyspark Cheat Sheet

Scikit Cheat Sheet

Scikit-learn

Scikit-learn Cheat Sheet

Scipy Cheat Sheet

SciPy

TesorFlow Cheat Sheet

Tensor Flow

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Tag: Machine Learning, Deep Learning, Artificial Intelligence, Neural Networks, Big Data