Orbitz.com Data Scraping

Orbitz.com Data Scraping, Web Scraping Orbitz.com , Data Extraction Orbitz.com , Scraping Web Data, Website Data Scraping, Email Scraping Orbitz.com , Email Database, Data Scraping Services, Scraping Contact Information, Data Scrubbing

Wednesday, 31 December 2014

Data Scraping Services with Proxy Data Scraping

Have you ever heard of "data scraping? Data Scraping is the process of gathering relevant information in the public domain on the internet (private areas even if the conditions are met) and stored in databases or spreadsheets for later use in various applications. Scraping data technology is not new and a successful businessman his fortune by using data scraping technology.

Sometimes owners of sites that are not derived much pleasure from the automated harvesting of their data. Webmasters have learned to deny access to web scrapers their websites using tools or methods that some IP addresses to block the content of the site here. scrapers data is left to either target a different site, or the script to move the harvest of a computer using a different IP address each time and get as much information as possible to "all computers finally blocked the nozzle.

Fortunately, there is a modern solution to this problem. Proxy data scraping technology solves the problem by using a proxy IP addresses. When your data scraping program performs an extraction of a website, the site thinks that it comes from a different IP address. For site owner, proxies just like scratching a short period of increased traffic around the world. They have very limited resources and tedious to block such a scenario, but more importantly - for the most part, they simply do not know they are scraped.

Now you can ask. "Where can I proxy data scraping technology for my project" The "do-it-yourself solution is free, unfortunately, not easy at all Creation of a database scraping proxy network takes time and requires you to either a group of IP addresses and servers can be used in place yet, the computer guru you need to call to get everything configured. You may consider hiring proxy servers hosting providers to select, but this option is usually quite expensive, but probably better than the alternative: dangerous and unreliable servers (but free) public proxy.

There are literally thousands of free proxy servers located all over the world are fairly easy to use. The trick is to find them. Hundreds of sites, list servers, but by placing a functioning, open and supports standard protocols that you need to a lesson in perseverance, trial and error will be. However, if you manage to find a working public representatives, there are dangers inherent in their use. First, you do not know who owns the server or activities taking place elsewhere on the server. Send applications or sensitive data via an open proxy is a bad idea. It's easy enough for a proxy server to keep all information you send or send it back to you to catch. If you choose the method of replacing the public, make sure you never a transaction through which you or anyone else would jeopardize the case of unsavory types are made aware of the data to send.

A less risky scenario for data scraping proxy is to hire a proxy connection that runs through the rotation of a large number of private IP addresses. There are a number of these companies available that claim to remove all Web logs, which you harvest anonymously on the web with a minimal threat of retaliation. Companies such as enterprise solutions offer a large http://www.Anonymizer.com anonymous proxy, but often carry significant costs of installing enough for you to continue.

The other advantage is that companies that own such networks can often help design and implement a set of proxy data scraping custom program instead of trying to work with a generic bone scraping. After performing a simple Google search, I quickly found a company (www.ScrapeGoat.com) that an anonymous proxy server provides for data scraping purposes. Or, according to their website, if you want to make life even easier, scrap goat can retrieve data for you and a variety of different formats to deliver, often before you could finish up your plate from the scraping program.

Whatever path you choose for your data scraping proxy need not let a few simple tips to thwart access to all the wonderful information that is stored on the World Wide Web!

Source:http://www.articlesbase.com/small-business-articles/data-scraping-services-with-proxy-data-scraping-4697825.html

Monday, 29 December 2014

How to scrape address from Google Maps

If you want to build a new online directory based website and want it to be popular with latest web contents, then you need the help of web scraping services from iWeb scraping. If you want to scrape address from maps.google.com, there is a specialized web scraping tool developed by iWeb scraping which can do the job for you. There are plenty of benefits with web scraping which includes market research, gathering customer information, managing product catalogs, compare prices, gather real estate data, gather job posting information etc. Web scraping technology is very popular nowadays and it saves lot of time and effort involved in manual extraction of data from websites.

The web scraping tools developed iWeb Scraping is very user-friendly and can extract specific information from targeted websites. It converts data from HTML web pages to useful formats like Excel spread sheets or Access database. Whatever web scraping requirements you have, you can contact iWeb Scraping as they have more than 3.5 years of web data extraction experience and offer the best prices in the industry. Also their services are available in 24x7 basis and free pilot projects will be done based on request.

Companies which require specific web data and look for an application which can automate the process and export the HTML data in structured format could benefit greatly from web scraping applications of iWeb scraping. You can easily extract data from multiple target websites, parse and re-assemble the information in HTML format to database or spread sheets as you wish. The application has simple point-and-click user-interface and any beginner can use it scrape address from Google Maps. If you want to gather address of people in particular region from Google maps, you can do it with help of web scraping application developed by iWebscraping.

Web Scraping is a technology that able to digest target website databases that are visible only as HTML web pages, and create a local, identical replica of those databases as a information or result. With our web scraping & web data extraction service we can capture web pages, then pin-point specific pieces of data/information you'd like to extract from web pages. What is needed in this process is much more than a Website crawler and set of Website wrappers. The time required to do web data extraction goes down in comparison to manually data copying and pasting job.

Source:http://www.articlesbase.com/information-technology-articles/how-to-scrape-address-from-google-maps-4683906.html

Saturday, 27 December 2014

Most Of The Recommended Web Scraping Data Into Business

More traditional Web search engines, websites visited, depending on how they were collected. The main disadvantage of these search engines is that they do not provide a method to extract the necessary information.

However, in modern times, the concept of scraping offs the website. Scraping all the relevant information and data contained in any web site can be found on the Internet together with the appearance.

Organizations and individuals to effectively and quickly recognized the need to gather information on the web scraping. Data structure that is more cut and paste can be accessed without having to contend with can not be collected.

If any other type of information to be able to arrange for the document. Traditional search engines use tools to harvest this website to a combination of individual clerks more sophisticated nuance with broad power. According to the criteria specified in the field of information is required.

News of the report on the software makes it easy for the crowd. The price and other analyzes to compare a pair of runs. Therefore, the Internet continues to work on the agencies that are required are a website as scrap. Web scraping by is the main reason for the growing number of companies.

Scraping the most reliable data Services Company based in India, offshore website provides information solutions to customers scraping. Data services to accomplish with your web search to try scraping, data mining, data conversion, data extraction, web scraping and web data in the data scraping.

Data Services are owned by scraping solution internet - India-based "Most of your trusted and reliable" service provider outsourcing. Data scraping Services offers high quality, accurate and manual internet scrape data and on the web scraping services at the lowest possible rate industry.

Data scraping Services is a firm based on the Indian expertise in outsourcing data entry, data processing, and Internet search and website scrape data. Data scraping Services offers great variety of data entry, data conversion, document scanning and data scraping service at the lowest possible rate industry since 2005. Services we offer cover the following areas; data entry, data mining, Web search, data conversion, data processing, scrape web sites, harvesting and collection of data internet email.

Data scraping Services follow the standard process to the highest quality Web search, data mining and web site services scratching. Search our website, data mining and data conversion projects to the process quality standards.

Most often the data must be scratched for the industry as part of lawyers, doctors, hospitals, students, schools, universities, chiropractor, dentists, hotels, property, real estate, pub, the bars, night club, a restaurant, and IT professionals. The most common medium to the database scraping and email numbers are directory business online, linked to, Twitter, Face book, social networking sites and search Google.

Data scraping service provider is the most trusted and reliable world of service, service of process data, data scrape, scrape data website, data mining, data extraction and business development database. We have already scraped some popular online business directories. We are only able to scrape public database available in any of the directory business.

Source:http://www.articlesbase.com/outsourcing-articles/most-of-the-recommended-web-scraping-data-into-business-5697814.html

Friday, 26 December 2014

Data Mining Explained

Overview

Data mining is the crucial process of extracting implicit and possibly useful information from data. It uses analytical and visualization techniques to explore and present information in a format which is easily understandable by humans.

Data mining is widely used in a variety of profiling practices, such as fraud detection, marketing research, surveys and scientific discovery.

In this article I will briefly explain some of the fundamentals and its applications in the real world.

Herein I will not discuss related processes of any sorts, including Data Extraction and Data Structuring.

The Effort

Data Mining has found its application in various fields such as financial institutions, health-care & bio-informatics, business intelligence, social networks data research and many more.

Businesses use it to understand consumer behavior, analyze buying patterns of clients and expand its marketing efforts. Banks and financial institutions use it to detect credit card frauds by recognizing the patterns involved in fake transactions.

The Knack

There is definitely a knack to Data Mining, as there is with any other field of web research activities. That is why it is referred as a craft rather than a science. A craft is the skilled practicing of an occupation.

One point I would like to make here is that data mining solutions offers an analytical perspective into the performance of a company depending on the historical data but one need to consider unknown external events and deceitful activities. On the flip side it is more critical especially for Regulatory bodies to forecast such activities in advance and take necessary measures to prevent such events in future.

In Closing

There are many important niches of Web Data Research that this article has not covered. But I hope that this article will provide you a stage to drill down further into this subject, if you want to do so!

Should you have any queries, please feel free to mail me. I would be pleased to answer each of your queries in detail.

Source: http://ezinearticles.com/?Data-Mining-Explained&id=4341782

Tuesday, 23 December 2014

Scraping Fantasy Football Projections from the Web

In this post, I show how to download fantasy football projections from the web using R.  In prior posts, I showed how to scrape projections from ESPN, CBS, NFL.com, and FantasyPros.  In this post, I compile the R scripts for scraping projections from these sites, in addition to the following sites: Accuscore, Fantasy Football Nerd, FantasySharks, FFtoday, Footballguys, FOX Sports, WalterFootball, and Yahoo.

Why Scrape Projections?

Scraping projections from multiple sources on the web allows us to automate importing the projections with a simple script.  Automation makes importing more efficient so we don’t have to manually download the projections whenever they’re updated.  Once we import all of the projections, there’s a lot we can do with them, like:

•    Determine who has the most accurate projections
•    Calculate projections for your league
•    Calculate players’ risk levels
•    Calculate players’ value over replacement
•    Identify sleepers
•    Calculate the highest value you should bid on a player in an auction draft
•    Draft the best starting lineup
•    Win your auction draft
•    Win your snake draft

The R Scripts

To scrape the projections from the websites, I use the readHTMLTable function from the XML package in R.  Here’s an example of how to scrape projections from FantasyPros:

1 2 3 4 5 6 7 8    

#Load libraries

library("XML")

#Download fantasy football projections from FantasyPros.com

qb_fp <- readHTMLTable("http://www.fantasypros.com/nfl/projections/qb.php", stringsAsFactors = FALSE)$data

rb_fp <- readHTMLTable("http://www.fantasypros.com/nfl/projections/rb.php", stringsAsFactors = FALSE)$data

wr_fp <- readHTMLTable("http://www.fantasypros.com/nfl/projections/wr.php", stringsAsFactors = FALSE)$data

te_fp <- readHTMLTable("http://www.fantasypros.com/nfl/projections/te.php", stringsAsFactors = FALSE)$data

view raw FantasyPros projections hosted with ? by GitHub

The R Scripts for scraping the different sources are located below:

1.    Accuscore
2.    CBS - Jamey Eisenberg
3.    CBS – Dave Richard
4.    CBS – Average
5.    ESPN
6.    Fantasy Football Nerd
7.    FantasyPros
8.    FantasySharks
9.    FFtoday
10.    Footballguys – David Dodds
11.    Footballguys – Bob Henry
12.    Footballguys – Maurile Tremblay
13.    Footballguys – Jason Wood
14.    FOX Sports
15.    NFL.com
16.    WalterFootball
17.    Yahoo

Density Plot

Below is a density plot of the projections from the different sources:Calculate projections

Conclusion

Scraping projections from the web is fast, easy, and automated with R.  Once you’ve downloaded the projections, there’s so much you can do with the data to help you win your league!  Let me know in the comments if there are other sources you want included (please provide a link).

Source:http://fantasyfootballanalytics.net/2014/06/scraping-fantasy-football-projections.html

Friday, 19 December 2014

Affordable Tooth Extractions

In recent times, the cost of dental care has skyrocketed. This includes all types of dentistry including teeth cleaning, extractions, and dental surgery. For those who live in Denver, CO, there are many options to choose from when paying for routine or emergency dental care. In fact, having a tooth extraction Denver might just be more easily afforded than what some may be aware of.

The flat fee for a tooth extraction in Denver may vary between dental offices. The type of extraction can also cause a difference in the price. A simple extraction may cost between $60-$75, but a wisdom tooth extraction that requires more time and effort could cost much more.

One of the great aspects of having dental services performed in Denver is the variety of payment forms that many dental offices accept. Most dental offices in this area accept several different health insurance plans that will allow patients to only be required to pay a small copay at the time of service. If you have chosen an in-network dental provider for your plan, this copay can be even less.

Many dental offices also provide services to those who have state medicaid or medicare as well. While cosmetic dental work may not be covered by these forms of health care, extractions are covered because they are considered a necessary part of the patients good health. Yearly checkups and teeth cleanings are also normally covered as a preventative measure to avoid bad dental health.

For those who may not have any type of health insurance, dental insurance, or state provided health care plan, most dental offices will offer a payment plan. The total cost will be calculated and can be divided up over a few months to make dental care more easily affordable. This will need to be arranged before services and you may need to pay a percentage of the cost upfront before any dental work is performed.

So, if you live in the Denver area and need to have a tooth extraction or other dental care, do not fear that it is impossible to obtain. By calling each dental office and discussing the types of payment forms they accept, you may find a payment plan that fits your budget nicely. You can compare the prices and options of all dentists in your area so that you can make a well informed decision more easily.

Source:http://ezinearticles.com/?Affordable-Tooth-Extractions&id=3241427

Wednesday, 17 December 2014

Web Data Extraction Services and Data Collection Form Website Pages

For any business market research and surveys plays crucial role in strategic decision making. Web scrapping and data extraction techniques help you find relevant information and data for your business or personal use. Most of the time professionals manually copy-paste data from web pages or download a whole website resulting in waste of time and efforts.

Instead, consider using web scraping techniques that crawls through thousands of website pages to extract specific information and simultaneously save this information into a database, CSV file, XML file or any other custom format for future reference.

Examples of web data extraction process include:

• Spider a government portal, extracting names of citizens for a survey
• Crawl competitor websites for product pricing and feature data
• Use web scraping to download images from a stock photography site for website design

Automated Data Collection

Web scraping also allows you to monitor website data changes over stipulated period and collect these data on a scheduled basis automatically. Automated data collection helps you discover market trends, determine user behavior and predict how data will change in near future.

Examples of automated data collection include:

• Monitor price information for select stocks on hourly basis
• Collect mortgage rates from various financial firms on daily basis
• Check whether reports on constant basis as and when required

Using web data extraction services you can mine any data related to your business objective, download them into a spreadsheet so that they can be analyzed and compared with ease.

In this way you get accurate and quicker results saving hundreds of man-hours and money!

With web data extraction services you can easily fetch product pricing information, sales leads, mailing database, competitors data, profile data and many more on a consistent basis.

Should you have any queries regarding Web Data extraction services, please feel free to contact us. We would strive to answer each of your queries in detail.

Source:http://ezinearticles.com/?Web-Data-Extraction-Services-and-Data-Collection-Form-Website-Pages&id=4860417

Tuesday, 16 December 2014

Scraping bids out for SS United States

Yesterday we posted that the Independence Seaport Museum doesn’t have the money to support the upkeep of the USS Olympia nor does it have the money to dredge the channel to tow her away.  On the other side of the river the USS New Jersey Battleship Museum is also having financial troubles. Given the current troubles centered around the Delaware River it almost seems a shame to report that the SS United States, which has been sitting of at Pier 84 in South Philadelphia for the last fourteen years,  is now being inspected by scrap dealers.  Then again, she is a rusting, gutted shell.  Perhaps it is time to let the old lady go.    As reported in Maritime Matters:

SS UNITED STATES For Scrap?

An urgent message was sent out today to the SS United States Conservancy alerting members that the fabled liner, currently laid up at Philadelphia, is being inspected by scrap merchants.

“Dear SS United States Conservancy Members and Supporters:

The SS United States Conservancy has learned that America’s national flagship, the SS United States, may soon be destroyed. The ship’s current owners, Genting Hong Kong (formerly Star Cruises Limited), through its subsidiary, Norwegian Cruise Line (NCL), are currently collecting bids from scrappers.

The ship’s current owners listed the vessel for sale in February, 2009. While NCL graciously offered the Conservancy first right of refusal on the vessel’s sale, the Conservancy has not been in a financial position to purchase the ship outright. However, the Conservancy has been working diligently to lay the groundwork for a public-private partnership to save and sustain the ship for generations to come.

Source:http://www.oldsaltblog.com/2010/03/scraping-bids-out-for-ss-united-states/

Wednesday, 10 December 2014

Finding & Removing Spam Blogs Who Scrape Content Onto Free Hosted Blogs

The more popular you become in the blogging world, the more crap you have to deal with!
Content scraping is one chore that can be dealt with swiftly once you understand what to do.
This post contains links which you can use to quickly and easily report content scrapers and spam blogs.
Please share this post and help clean up spam blogs and punish content scrapers.
First step is to find your url’s which have been scraped of content and then get the scrapers spam blog removed.

Some of the tools i use to do this are:

    Google Webmaster Tools
    Google Alerts


Finding Scraped Content
Login to your Google Webmaster Tools account and go to traffic > links to your site.
You should see something like this:
Webmaster Tools Links to Your Site

The first domain is a site which has copied and embedded my homepage which i have already dealt with.
The second site is a search engine.
The third domain is the one i want to deal with.

A common method scrapers use is to post the scraped content from your rss feed on to a free hosted blog like WordPress.com or blogger.com.

Once you click the WordPress.com link in webmaster tools, you’ll find all the url’s which have been scraped.
Links to Your Site

There’s 32 url’s which have been linked to so its simply a matter of clicking each of your links and finding the culprits.

The first link is my homepage which has been linked to by legit domains like WordPress developers.
The others are mainly linked to by spam blogs who have scraped the content and used a free hosted service which in this case is WordPress.com.
WordPress.com Links to Your Site
 Reporting & Removing Spam Blogs

Once you have the url’s of the content scraping blogs as seen in the screenshot above:

    Fill in this basic form to report spam to WordPress.com
    Fill in this form to report copyright content to WordPress.com
    Use this form to report Blogspot and Blogger.com content which has been scraped.
    Fill in one of these forms to remove content from Google

Google Alerts

Its very easy to setup a Google alert to find your post titles when they get scraped.
If you’ve setup the WordPress SEO plugin correctly, you should have included your site title at the end of all your post titles.
Then all you need to do is setup a Google alert for your site title and you’ll be notified every time a scraper links to your content.

Link Notifications

You may also receive a pingback or trackback if you have this feature enabled in your discussion settings.

Link Notifications
RSS Feed Links


Most content scrapers use automated software to scrape the content from RSS feeds.
Make sure you configure your Reading settings so only a summary is displayed.
Reading Settings Feed Summary

Next step is to configure the settings in Yoast’s SEO plugin so links back to your site are included in all RSS feed post summaries.

RSS Feed Links
This will help search engines identify you and your domain as the original author of the content.
There’s other services like copyscape and dmca which can help you protect your sites content if you’re prepared to pay a premium.
That’s it folks.
Its easy to find and get spam sites removed once you know what to do.
Hope you don’t have to deal with this garbage to often.
Ever found out your content has been scraped?
What did you do about it?

Source: http://wpsites.net/blogging/content-scraping-monitoring-and-prevention-tips/

Monday, 1 December 2014

What you have to know before requesting web scraping services?

Before you request web scraping services you have to know what are your needs (what data you need, structure of it and where you can find this data).

Step 1: Define what data you need?

Data needs depending on purpose, if you want to find new customers you probably need contact data from players in your industry. Also if you want to study your competitors you need to define who are they. Only after that you can select data sources (websites feeds or other electronic sources) for this extraction.

In many cases for discovering and defining data sources are used search engines like Google, Bing, Yahoo, and others.

Step 2: Structure of data
Data structure it’s directly linked to usage purpose. In many cases data structure it’s a table where a row represents an entity and a cell of this row represents a property of this entity. In other cases Data structure is a a chart or another graphic representation builder with data extracted from a web source.

Step 3: Number of data extraction

In many cases is needed one time data extraction. In other cases when you need a regular report, are needed periodically extractions.

If you have defined all of above points you are ready to request a quote and an amount estimation from this contact form.

Source: http://thewebminer.com/blog/2013/08/

Friday, 28 November 2014

Scraping R-bloggers with Python – Part 2

In my previous post I showed how to write a small simple python script to download the pages of R-bloggers.com. If you followed that post and ran the script, you should have a folder on your hard drive with 2409 .html files labeled post1.html , post2.html and so forth. The next step is to write a small script that extract the information we want from each page, and store that information in a .csv file that is easily read by R. In this post I will show how to extract the post title, author name and date of a given post and store it in a .csv file with a unique id.

To do this open a document in your favorite python editor (I like to use aquamacs) and name it: extraction.py. As in the previous post we start by importing the modules that we will use for the extraction:

from BeautifulSoup import BeautifulSoup

import os
import re

As in the previous post we will be using the BeautifulSoup module to extract the relevant information from the pages. The os module is used to get a list of file from the directory where we have saved the .html files, and finally the re module allows us to use regular expressions to format the titles that include a comma value or a newline value (\n). We need to remove these as they would mess up the formatting of the .csv file.

After having read in the modules, we need to get a list of files that we can iterate over. First we need to specify the path were the files are saved, and then we use the os module to get all the filenames in the specified directory:

path = "/Users/thomasjensen/Documents/RBloggersScrape/download"

listing = os.listdir(path)

It might be that there are other files in the given directory, hence we apply a filter, in shape of a list comprehension, to weed out any file names that do not match our naming scheme:

listing = [name for name in listing if re.search(r"post\d+\.html",name) != None]

Notice that a regular expression was used to determine whether a given name in the list matched our naming scheme. For more on regular expressions have a look at this site.

The final steps in preparing our extraction is to change the working directory to where we have our .html files, and create an empty dictionary:

os.chdir(path)
data = {}

Dictionaries are one of the great features of Python. Essentially a dictionary is a mapping of a key to a specific value, however the fact that dictionaries can be nested within each other, allows us to create data structures similar to R’s data frames.

Now we are ready to begin extracting information from our downloaded pages. Much as in the previous post, we will loop over all the file names, read each file into Python and create a BeautifulSoup object from the file:

for page in listing:
    site = open(page,"rb")
    soup = BeautifulSoup(site)

In order to store the values we extract from a given page, we update the dictionary with a unique key for the page. Since our naming scheme made sure that each file had a unique name, we simply remove the .html part from the page name, and use that as our key:

key = re.sub(".html","",page)

data.update({key:{}})

This will create a mapping between our key and an empty dictionary, nested within the data dictionary. Once this is done we can start extract information and store it in our newly created nested dictionary. The content we want is located in the main column, which has the id tag “leftcontent” in the html code. To get at this we use find() function on soup object created above:

content = soup.find("div", id = "leftcontent")

The first “h1” tag in our content object contains the title, so again we will use the find() function on the content object, to find the first “h1” tag:

title = content.findNext("h1").text

To get the text within the “h1” tag the .text had been added to our search with in the content object.

To find the author name, we are lucky that there is a class of “div” tags called “meta” which contain a link with the author name in it. To get the author name we simply find the meta div class and search for a link. Then we pull out the text of the link tag:

author = content.find("div",{"class":"meta"}).findNext("a").text

Getting the date is a simple matter as it is nested within div tag with the class “date”:

date = content.find("div",{"class":"date"}).text

Once we have the three variables we put them in dictionaries that are nested within the nested dictionary we created with the key:

data[key]["title"] = title
data[key]["author"] = author
data[key]["date"] = date

Once we have run the loop and gone through all posts, we need to write them in the right format to a .csv file. To begin with we open a .csv file names output:

output = open("/Users/thomasjensen/Documents/RBloggersScrape/output.csv","wb")

then we create a header that contain the variable names and write it to the output.csv file as the first row:

variables = unicode(",".join(["id","date","author","title"]))
header = variables + "\n"
output.write(header.encode("utf8"))

Next we pull out all the unique keys from our dictionary that represent individual posts:

keys = data.keys()

Now it is a simple matter of looping through all the keys, pull out the information associated with each key, and write that information to the output.csv file:

for key in keys:
    print key
    id = key
    date = re.sub(",","",data[key]["date"])
    author = data[key]["author"]
    title = re.sub(",","",data[key]["title"])
    title = re.sub("\\n","",title)
    linelist = [id,date,author,title]
    linestring = unicode(",".join(linelist))
    linestring = linestring + "\n"
    output.write(linestring.encode("utf-8"))

Notice that we first create four variables that contain the id, date, author and title information. With regards to the title we use two regular expressions to remove any commas and “\n” from the title, as these would create new columns or new line breaks in the output.csv file. Finally we put the variables together in a list, and turn the list into a string with the list items separated by a comma. Then a linebreak is added to the end of the string, and the string is written to the output.csv file. As a last step we close the file connection:

output.close()

And that is it. If you followed the steps you should now have a csv file in your directory with 2409 rows, and four variables – ready to be read into R. Stay tuned for the next post which will show how we can use this data to see how R-bloggers has developed since 2005. The full extraction script is shown below:

from BeautifulSoup import BeautifulSoup

import os
import re

 path = "/Users/thomasjensen/Documents/RBloggersScrape/download"
 listing = os.listdir(path)

listing = [name for name in listing if re.search(r"post\d+\.html",name) != None]
 os.chdir(path)
 data = {}
 for page in listing:
site = open(page,"rb")
soup = BeautifulSoup(site)
key = re.sub(".html","",page)
print key
data.update({key:{}})
 content = soup.find("div", id = "leftcontent")
title = content.findNext("h1").text
author = content.find("div",{"class":"meta"}).findNext("a").text
date = content.find("div",{"class":"date"}).text
data[key]["title"] = title
data[key]["author"] = author
data[key]["date"] = date

 output = open("/Users/thomasjensen/Documents/RBloggersScrape/output.csv","wb")

 keys = data.keys()
 variables = unicode(",".join(["id","date","author","title"]))
 header = variables + "\n"
 output.write(header.encode("utf8"))
 for key in keys:
print key
id = key
date = re.sub(",","",data[key]["date"])
author = data[key]["author"]
title = re.sub(",","",data[key]["title"])
title = re.sub("\\n","",title)
linelist = [id,date,author,title]
linestring = unicode(",".join(linelist))
linestring = linestring + "\n"
output.write(linestring.encode("utf-8"))
 output.close()

Source:http://www.r-bloggers.com/scraping-r-bloggers-with-python-part-2/

Thursday, 27 November 2014

Data Mining and Frequent Datasets

I've been doing some work for my exams in a few days and I'm going through some past papers but unfortunately there are no corresponding answers. I've answered the question and I was wondering if someone could tell me if I am correct.

My question is

    (c) A transactional dataset, T, is given below:
    t1: Milk, Chicken, Beer
    t2: Chicken, Cheese
    t3: Cheese, Boots
    t4: Cheese, Chicken, Beer,
    t5: Chicken, Beer, Clothes, Cheese, Milk
    t6: Clothes, Beer, Milk
    t7: Beer, Milk, Clothes

    Assume that minimum support is 0.5 (minsup = 0.5).

    (i) Find all frequent itemsets.

Here is how I worked it out:

    Item : Amount
    Milk : 4
    Chicken : 4
    Beer : 5
    Cheese : 4
    Boots : 1
    Clothes : 3

Now because the minsup is 0.5 you eliminate boots and clothes and make a combo of the remaining giving:

    {items} : Amount
    {Milk, Chicken} : 2
    {Milk, Beer} : 4
    {Milk, Cheese} : 1
    {Chicken, Beer} : 3
    {Chicken, Cheese} : 3
    {Beer, Cheese} : 2

Which leaves milk and beer as the only frequent item set then as it is the only one above the minsup?

data mining

Nanor

3 Answers

There are two ways to solve the problem:

    using Apriori algorithm
    Using FP counting

Assuming that you are using Apriori, the answer you got is correct.

The algorithm is simple:

First you count frequent 1-item sets and exclude the item-sets below minimum support.

Then count frequent 2-item sets by combining frequent items from previous iteration and exclude the item-sets below support threshold.

The algorithm can go on until no item-sets are greater than threshold.

In the problem given to you, you only get 1 set of 2 items greater than threshold so you can't move further.

There is a solved example of further steps on Wikipedia here.

You can refer "Data Mining Concepts and Techniques" by Han and Kamber for more examples.

141

There is more than two algorithms to solve this problem. I will just mention a few of them: Apriori, FPGrowth, Eclat, HMine, DCI, Relim, AIM, etc. –  Phil Mar 5 '13 at 7:18

OK to start, you must first understand, data mining (sometimes called data or knowledge discovery) is the process of analyzing data from different perspectives and summarizing it into useful information - information that can be used to increase revenue, cuts costs, or both. Data mining software is one of a number of analytical tools for analyzing data. It allows users to analyze data from many different dimensions or angles, categorize it, and summarize the relationships identified. Technically, data mining is the process of finding correlations or patterns among dozens of fields in large relational databases.

Now, the amount of raw data stored in corporate databases is exploding. From trillions of point-of-sale transactions and credit card purchases to pixel-by-pixel images of galaxies, databases are now measured in gigabytes and terabytes. (One terabyte = one trillion bytes. A terabyte is equivalent to about 2 million books!) For instance, every day, Wal-Mart uploads 20 million point-of-sale transactions to an A&T massively parallel system with 483 processors running a centralized database.

Raw data by itself, however, does not provide much information. In today's fiercely competitive business environment, companies need to rapidly turn these terabytes of raw data into significant insights into their customers and markets to guide their marketing, investment, and management strategies.

Now you must understand that association rule mining is an important model in data mining. Its mining algorithms discover all item associations (or rules) in the data that satisfy the user-specified minimum support (minsup) and minimum confidence (minconf) constraints. Minsup controls the minimum number of data cases that a rule must cover. Minconf controls the predictive strength of the rule.

Since only one minsup is used for the whole database, the model implicitly assumes that all items in the data are of the same nature and/or have similar frequencies in the data. This is, however, seldom the case in real- life applications. In many applications, some items appear very frequently in the data, while others rarely appear. If minsup is set too high, those rules that involve rare items will not be found. To find rules that involve both frequent and rare items, minsup has to be set very low.

This may cause combinatorial explosion because those frequent items will be associated with one another in all possible ways. This dilemma is called the rare item problem. This paper proposes a novel technique to solve this problem. The technique allows the user to specify multiple minimum supports to reflect the natures of the items and their varied frequencies in the database. In rule mining, different rules may need to satisfy different minimum supports depending on what items are in the rules.

Given a set of transactions T (the database), the problem of mining association rules is to discover all association rules that have support and confidence greater than the user-specified minimum support (called minsup) and minimum confidence (called minconf).

I hope that once you understand the very basics of data mining that the answer to this question shall become apparent.

1

The Apriori algorithm is based on the idea that for a pair o items to be frequent, each individual item should also be frequent. If the hamburguer-ketchup pair is frequent, the hamburger itself must also appear frequently in the baskets. The same can be said about the ketchup.

So for the algorithm, it is established a "threshold X" to define what is or it is not frequent. If an item appears more than X times, it is considered frequent.

The first step of the algorithm is to pass for each item in each basket, and calculate their frequency (count how many time it appears). This can be done with a hash of size N, where the position y of the hash, refers to the frequency of Y.

If item y has a frequency greater than X, it is said to be frequent.

In the second step of the algorithm, we iterate through the items again, computing the frequency of pairs in the baskets. The catch is that we compute only for items that are individually frequent. So if item y and item z are frequent on itselves, we then compute the frequency of the pair. This condition greatly reduces the pairs to compute, and the amount of memory taken.

Once this is calculated, the frequencies greater than the threshold are said frequent itemset.

Source: http://stackoverflow.com/questions/14164853/data-mining-and-frequent-datasets?rq=1