Data science with the Linux Data Science Virtual Machine on Azure. This walkthrough shows you how to perform several common data science tasks with the Linux Data Science VM. The Linux Data Science Virtual Machine DSVM is a virtual machine image available on Azure that is pre installed with a collection of tools commonly used for data analytics and machine learning. The key software components are itemized in the Provision the Linux Data Science Virtual Machine topic. The VM image makes it easy to get started doing data science in minutes, without having to install and configure each of the tools individually. You can easily scale up the VM, if needed, and stop it when not in use. The Lost Inca Prophecy Setup. So this resource is both elastic and cost efficient. The data science tasks demonstrated in this walkthrough follow the steps outlined in the Team Data Science Process. This process provides a systematic approach to data science that enables teams of data scientists to effectively collaborate over the lifecycle of building intelligent applications. The data science process also provides an iterative framework for data science that can be followed by an individual. We analyze the spambase dataset in this walkthrough. This is a set of emails that are marked as either spam or ham meaning they are not spam, and also contains some statistics on the content of the emails. The statistics included are discussed in the next but one section. Prerequisites. Before you can use a Linux Data Science Virtual Machine, you must have the following Download the spambase dataset. The spambase dataset is a relatively small set of data that contains only 4. This is a convenient size to use when demonstrating that some of the key features of the Data Science VM as it keeps the resource requirements modest. Note. This walkthrough was created on a D2 v. Linux Data Science Virtual Machine. This size DSVM is capable of handling the procedures in this walkthrough. If you need more storage space, you can create additional disks and attach them to your VM. These disks use persistent Azure storage, so their data is preserved even when the server is reprovisioned due to resizing or is shut down. To add a disk and attach it to your VM, follow the instructions in Add a disk to a Linux VM. These steps use the Azure Command Line Interface Azure CLI, which is already installed on the DSVM. So these procedures can be done entirely from the VM itself. Another option to increase storage is to use Azure files. To download the data, open a terminal window and run this command wget http archive. The downloaded file does not have a header row, so lets create another file that does have a header. Run this command to create a file with the appropriate headers echo wordfreqmake, wordfreqaddress, wordfreqall, wordfreq3d,wordfreqour, wordfreqover, wordfreqremove, wordfreqinternet,wordfreqorder, wordfreqmail, wordfreqreceive, wordfreqwill,wordfreqpeople, wordfreqreport, wordfreqaddresses, wordfreqfree,wordfreqbusiness, wordfreqemail, wordfreqyou, wordfreqcredit,wordfreqyour, wordfreqfont, wordfreq0. Paren,charfreqleft. Bracket, charfreqexclamation, charfreqdollar, charfreqpound, capitalrunlengthaverage,capitalrunlengthlongest, capitalrunlengthtotal, spam headers. Then concatenate the two files together with the command cat spambase. Headers. data. The dataset has several types of statistics on each email Columns like wordfreqWORD indicate the percentage of words in the email that match WORD. For example, if wordfreqmake is 1, then 1 of all words in the email were make. One of the most annoying trends in video games is the word exclusive, which perhaps once meant limited or restricted but now, thanks to Microsoft. This walkthrough shows you how to perform several common data science tasks with the Linux Data Science VM. The Linux Data Science Virtual Machine DSVM is a virtual. This package contains classes for decoding the Microsoft Office Drawing format otherwise known as escher henceforth known in POI as the Dreadful Drawing. Learn what web platform issues Microsoft Edge supports and is currently working on. Columns like charfreqCHAR indicate the percentage of all characters in the email that were CHAR. Explore the dataset with Microsoft R Open. Lets examine the data and do some basic machine learning with R. The Data Science VM comes with Microsoft R Open pre installed. The multithreaded math libraries in this version of R offer better performance than various single threaded versions. Microsoft R Open also provides reproducibility by using a snapshot of the CRAN package repository. To get copies of the code samples used in this walkthrough, clone the Azure Machine Learning Data Science repository using git, which is pre installed on the VM. From the git command line, run git clone https github. AzureAzure Machine. Microsoft claims Bing, its search engine for people who have just unboxed a new computer and are trying to find out where to download Chrome, is bigger than you think. This July, we asked for software tips from the 2017 Microsoft Office National Champions, a set of charming teens who are officially the best at using PowerPoint, Word. You have not yet voted on this site If you have already visited the site, please help us classify the good from the bad by voting on this site. GraphicsMagicks gm provides a suite of utilities for creating, comparing, converting, editing, and displaying images. All of the utilities are provided as sub. A short description of mazes and how to create them. Definition of different mazetypes and their algorithms. Java Data Structures 2nd Edition End of the World Production, LLC. How To Draw A Binary Tree In Microsoft Word' title='How To Draw A Binary Tree In Microsoft Word' />Learning Data. Science. Open a terminal window and start a new R session with the R interactive console. Note. You can also use RStudio for the following procedures. To install RStudio, execute this command at a terminal. DesktopDSVM toolsinstall. RStudio. sh. To import the data and set up the environment, run data lt read. Headers. data. To see summary statistics about each column summarydata. For a different view of the data strdata. This shows you the type of each variable and the first few values in the dataset. The spam column was read as an integer, but its actually a categorical variable or factor. To set its type dataspam lt as. To do some exploratory analysis, use the ggplot. R that is already installed on the VM. Note, from the summary data displayed earlier, that we have summary statistics on the frequency of the exclamation mark character. Lets plot those frequencies here with the following commands libraryggplot. Since the zero bar is skewing the plot, lets get rid of it emailwithexclamation datadatacharfreqexclamation 0,. There is a non trivial density above 1 that looks interesting. Lets look at just that data ggplotdatadatacharfreqexclamation 1, geomhistogramaesxcharfreqexclamation, binwidth0. Then split it by spam vs ham ggplotdatadatacharfreqexclamation 1, aesxcharfreqexclamation. Distribution of spam nby frequency of. Density. These examples should enable you to make similar plots of the other columns to explore the data contained in them. Train and test an ML model. Now lets train a couple of machine learning models to classify the emails in the dataset as containing either span or ham. We train a decision tree model and a random forest model in this section and then test their accuracy of their predictions. Note. The rpart Recursive Partitioning and Regression Trees package used in the following code is already installed on the Data Science VM. First, lets split the dataset into training and test sets rnd lt runifdimdata1. Set subsetdata, rnd lt 0. Set subsetdata, rnd 0. And then create a decision tree to classify the emails. Set. plotmodel. Here is the result To determine how well it performs on the training set, use the following code train. Set. Pred lt predictmodel. Set, type class. Actual Class train. Setspam, Predicted Class train. Set. Pred. accuracy lt sumdiagtsumt. To determine how well it performs on the test set test. Set. Pred lt predictmodel. Set, type class. Actual Class test. Setspam, Predicted Class test. Set. Pred. accuracy lt sumdiagtsumt. Lets also try a random forest model. Random forests train a multitude of decision trees and output a class that is the mode of the classifications from all of the individual decision trees. They provide a more powerful machine learning approach as they correct for the tendency of a decision tree model to overfit a training dataset. Forest. train. Vars lt setdiffcolnamesdata, spam. Forestxtrain. Set, train. Vars, ytrain. Setspam. Set. Pred lt predictmodel. Set, train. Vars, type class. Actual Class train. Setspam, Predicted Class train. Set. Pred. test. Set. Pred lt predictmodel. Set, train. Vars, type class. Actual Class test. Setspam, Predicted Class test. Set. Pred. accuracy lt sumdiagtsumt. Deploy a model to Azure MLAzure Machine Learning Studio Azure. ML is a cloud service that makes it easy to build and deploy predictive analytics models. One of the nice features of Azure. String computer science Wikipedia. In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable. The latter may allow its elements to be mutated and the length changed, or it may be fixed after creation. A string is generally understood as a data type and is often implemented as an array data structure of bytes or words that stores a sequence of elements, typically characters, using some character encoding. A string may also denote more general arrays or other sequence or list data types and structures. Depending on programming language and precise data type used, a variable declared to be a string may either cause storage in memory to be statically allocated for a predetermined maximum length or employ dynamic allocation to allow it to hold a variable number of elements. When a string appears literally in source code, it is known as a string literal or an anonymous string. In formal languages, which are used in mathematical logic and theoretical computer science, a string is a finite sequence of symbols that are chosen from a set called an alphabet. Formal theoryeditLet be a non emptyfinite set of symbols alternatively called characters, called the alphabet. No assumption is made about the nature of the symbols. A string or word over is any finite sequence of symbols from. For example, if 0, 1, then 0. The length of a string s is the number of symbols in s the length of the sequence and can be any non negative integer it is often denoted as s. The empty string is the unique string over of length 0, and is denoted or. The set of all strings over of length n is denoted n. For example, if 0, 1, then 2 0. Note that 0 for any alphabet. The set of all strings over of any length is the Kleene closure of and is denoted. In terms of n,nN0ndisplaystyle Sigma bigcup nin mathbb N cup 0Sigma nFor example, if 0, 1, then, 0, 1, 0. Although the set itself is countably infinite, each element of is a string of finite length. A set of strings over i. For example, if 0, 1, the set of strings with an even number of zeros, 1, 0. Concatenation and substringseditConcatenation is an important binary operation on For any two strings s and t in their concatenation is defined as the sequence of symbols in s followed by the sequence of characters in t, and is denoted st. For example, if a, b,., z, s bear, and t hug, then st bearhug and ts hugbear. String concatenation is an associative, but non commutative operation. The empty string serves as the identity element for any string s, s s s. Therefore, the set and the concatenation operation form a monoid, the free monoid generated by. In addition, the length function defines a monoid homomorphism from to the non negative integers that is, a function L N0displaystyle L Sigma mapsto mathbb N cup 0, such that LstLsLts,tdisplaystyle LstLsLtquad forall s,tin Sigma. A string s is said to be a substring or factor of t if there exist possibly empty strings u and v such that t usv. The relation is a substring of defines a partial order on the least element of which is the empty string. Prefixes and suffixeseditA string s is said to be a prefix of t if there exists a string u such that t su. If u is nonempty, s is said to be a proper prefix of t. Symmetrically, a string s is said to be a suffix of t if there exists a string u such that t us. If u is nonempty, s is said to be a proper suffix of t. Suffixes and prefixes are substrings of t. Both the relations is a prefix of and is a suffix of are prefix orders. RotationseditA string s uv is said to be a rotation of t if t vu. For example, if 0, 1 the string 0. ReversaleditThe reverse of a string is a string with the same symbols but in reverse order. For example, if s abc where a, b, and c are symbols of the alphabet, then the reverse of s is cba. A string that is the reverse of itself e. Lexicographical orderingeditIt is often useful to define an ordering on a set of strings. If the alphabet has a total order cf. For example, if 0, 1 and 0 lt 1, then the lexicographical order on includes the relationships lt 0 lt 0. The lexicographical order is total if the alphabetical order is, but isnt well founded for any nontrivial alphabet, even if the alphabetical order is. See Shortlex for an alternative string ordering that preserves well foundedness. String operationseditA number of additional operations on strings commonly occur in the formal theory. These are given in the article on string operations. Topologyedit. Hypercube of binary strings of length 3. Strings admit the following interpretation as nodes on a graph Fixed length strings can be viewed as nodes on a hypercube. Variable length strings of finite length can be viewed as nodes on the k ary tree, where k is the number of symbols in Infinite strings otherwise not considered here can be viewed as infinite paths on the k ary tree. The natural topology on the set of fixed length strings or variable length strings is the discrete topology, but the natural topology on the set of infinite strings is the limit topology, viewing the set of infinite strings as the inverse limit of the sets of finite strings. This is the construction used for the p adic numbers and some constructions of the Cantor set, and yields the same topology. Isomorphisms between string representations of topologies can be found by normalizing according to the lexicographically minimal string rotation. String datatypeseditA string datatype is a datatype modeled on the idea of a formal string. Strings are such an important and useful datatype that they are implemented in nearly every programming language. In some languages they are available as primitive types and in others as composite types. The syntax of most high level programming languages allows for a string, usually quoted in some way, to represent an instance of a string datatype such a meta string is called a literal or string literal. String lengtheditAlthough formal strings can have an arbitrary but finite length, the length of strings in real languages is often constrained to an artificial maximum. In general, there are two types of string datatypes fixed length strings, which have a fixed maximum length to be determined at compile time and which use the same amount of memory whether this maximum is needed or not, and variable length strings, whose length is not arbitrarily fixed and which can use varying amounts of memory depending on the actual requirements at run time. Most strings in modern programming languages are variable length strings. Of course, even variable length strings are limited in length by the number of bits available to a pointer, and by the size of available computer memory. The string length can be stored as a separate integer which may put an artificial limit on the length or implicitly through a termination character, usually a character value with all bits zero. See also Null terminated below. Character encodingeditString datatypes have historically allocated one byte per character, and, although the exact character set varied by region, character encodings were similar enough that programmers could often get away with ignoring this, since characters a program treated specially such as period and space and comma were in the same place in all the encodings a program would encounter. These character sets were typically based on ASCII or EBCDIC. If text in one encoding was displayed on a system using a different encoding, text was often mangled, though often somewhat readable and some computer users actually learned to read the mangled text.