Big Data, R and SAP HANA: Analyze 200 Million Data Points and Later Visualize in HTML5 Using D3 - Part III

Mash-up Airlines Performance Data with Historical Weather Data to Pinpoint Weather Related Delays

For this exercise, I combined following four separate blogs that I did on BigData, R and SAP HANA.  Historical airlines and weather data were used for the underlying analysis. The aggregated output of this analysis was outputted in JSON which was visualized in HTML5, D3 and Google Maps.  The previous blogs on this series are:

1. Big Data, R and HANA: Analyze 200 Million Data Points and Later Visualize in HTML5 Using D3 - Part II
2. Big Data, R and HANA: Analyze 200 Million Data Points and Later Visualize Using Google Maps
3. Getting Historical Weather Data in R and SAP HANA 
4. Tracking SFO Airport's Performance Using R, HANA and D3

In this blog, I wanted to mash-up disparate data sources in R and HANA by combining airlines data with weather data to understand the reasons behind the airport/airlines delay.  Why weather - because weather is one of the commonly cited reasons in the airlines industry for flight delays.  Fortunately, the airlines data breaks up the delay by weather, security, late aircraft etc., so weather related delays can be isolated and then the actual weather data can be mashed-up to validate the airlines' claims.  However, I will not be doing this here, I will just be displaying the mashed-up data.

I have intentionally focused on the three bay-area airports and have used last 4 years of historical data to visualize the airport's performance using a HTML5 calendar built from scratch using D3.js.  One can use all 20 years of data and for all the airports to extend this example.  I had downloaded historical weather data for the same 2005-2008 period for SFO and SJC airports as shown in my previous blog (For some strange reasons, there is no weather data for OAK, huh?).  Here is how the final result will look like in HTML5:

Click here to interact with the live example.  Hover over any cell in the live example and a tool tip with comprehensive analytics will show the break down of the performance delay for the selected cell including weather data and correct icons* - result of a mash-up.  Choose a different airport from the drop-down to change the performance calendar. 

* Weather icons are properties of Weather Underground.

As anticipated, SFO airport had more red on the calendar than SJC and OAK.  SJC definitely is the best performing airport in the bay-area.  Contrary to my expectation, weather didn't cause as much havoc on SFO as one would expect, strange?

Creating a mash-up in R for these two data-sets was super easy and a CSV output was produced to work with HTML5/D3.  Here is the R code and if it not clear from all my previous blogs: I just love data.table package.

###########################################################################################  

# Percent delayed flights from three bay area airports, a break up of the flights delay by various reasons, mash-up with weather data

###########################################################################################  

baa.hp.daily.flights <- baa.hp[,list( TotalFlights=length(DepDelay), CancelledFlights=sum(Cancelled, na.rm=TRUE)), 

                             by=list(Year, Month, DayofMonth, Origin)]

setkey(baa.hp.daily.flights,Year, Month, DayofMonth, Origin)

baa.hp.daily.flights.delayed <- baa.hp[DepDelay>15,

                                     list(DelayedFlights=length(DepDelay), 

                                      WeatherDelayed=length(WeatherDelay[WeatherDelay>0]),

                                      AvgDelayMins=round(sum(DepDelay, na.rm=TRUE)/length(DepDelay), digits=2),

                                      CarrierCaused=round(sum(CarrierDelay, na.rm=TRUE)/sum(DepDelay, na.rm=TRUE), digits=2),

                                      WeatherCaused=round(sum(WeatherDelay, na.rm=TRUE)/sum(DepDelay, na.rm=TRUE), digits=2),

                                      NASCaused=round(sum(NASDelay, na.rm=TRUE)/sum(DepDelay, na.rm=TRUE), digits=2),

                                      SecurityCaused=round(sum(SecurityDelay, na.rm=TRUE)/sum(DepDelay, na.rm=TRUE), digits=2),

                                      LateAircraftCaused=round(sum(LateAircraftDelay, na.rm=TRUE)/sum(DepDelay, na.rm=TRUE), digits=2)), by=list(Year, Month, DayofMonth, Origin)]

setkey(baa.hp.daily.flights.delayed, Year, Month, DayofMonth, Origin)

# Merge two data-tables

baa.hp.daily.flights.summary <- baa.hp.daily.flights.delayed[baa.hp.daily.flights,list(Airport=Origin,

                           TotalFlights, CancelledFlights, DelayedFlights, WeatherDelayed, 

                           PercentDelayedFlights=round(DelayedFlights/(TotalFlights-CancelledFlights), digits=2),

                           AvgDelayMins, CarrierCaused, WeatherCaused, NASCaused, SecurityCaused, LateAircraftCaused)]

setkey(baa.hp.daily.flights.summary, Year, Month, DayofMonth, Airport)

# Merge with weather data

baa.hp.daily.flights.summary.weather <-baa.weather[baa.hp.daily.flights.summary]

baa.hp.daily.flights.summary.weather$Date <- as.Date(paste(baa.hp.daily.flights.summary.weather$Year, 

                                                           baa.hp.daily.flights.summary.weather$Month, 

                                                           baa.hp.daily.flights.summary.weather$DayofMonth, 

                                                           sep="-"),"%Y-%m-%d")

# remove few columns

baa.hp.daily.flights.summary.weather <- baa.hp.daily.flights.summary.weather[, 

            which(!(colnames(baa.hp.daily.flights.summary.weather) %in% c("Year", "Month", "DayofMonth", "Origin"))), with=FALSE]

#Write the output in both JSON and CSV file formats

objs <- baa.hp.daily.flights.summary.weather[, getRowWiseJson(.SD), by=list(Airport)]

# You have now (Airportcode, JSONString), Once again, you need to attach them together.

row.json <- apply(objs, 1, function(x) paste('{\"AirportCode\":"', x[1], '","Data\":', x[2], '}', sep=""))

json.st <- paste('[', paste(row.json, collapse=', '), ']')

writeLines(json.st, "baa-2005-2008.summary.json")                 

write.csv(baa.hp.daily.flights.summary.weather, "baa-2005-2008.summary.csv", row.names=FALSE)

Happy Coding!

Updated Sentiment Analysis and a Word Cloud for Netflix - The R Way!

The Netflix investors must be happy and cheerful as the stock is up more than 78% since the beginning of the year (YES, 78%, Source: Yahoo Finance!).  I am not going to talk about what turned the stock around after a much talked/hyped about Netflix debacle of the late 2011 that earned Reed Hastings quite a few UNWANTED title and every one demanded his resignation from the top post.  Not so fast, Mr. Bear!  Reed Hastings must be smiling!  After a stellar performance this year including carefully released stats on viewership, streaming hours as well as a solid Q4'11 earnings, Netflix is back and most importantly viewers are back!

Well, is is not coincidental that the sentiment for Netflix is also improving, 68% of the tweets now have positive sentiment.  See the table below:

Total	Positive	Negative	Average	Total	Sentiment
Tweets  Fetched	Tweets	Tweets	Score	Tweets
499	171	80	0.281	251	68%

*Make sure you understand and interpret this analysis correctly. This analysis is not based on NLP. 

I updated the sentiment analysis that I did last year, http://goo.gl/fkfPy ,  (I was then just beginning to play with Twitter and Text Mining packages in R) and used advanced packages like "TM" and  "WordCloud".  The new analysis is based on more than 6,800 words which are most commonly prescribed in various sentiment analysis blogs/books. (Check out Hu and Liu http://www.cs.uic.edu/~liub/FBS/sentiment-analysis.html)

I came across this excellent blog by Jeffrey Bean, @JeffreyBean, (http://goo.gl/RPkFX) and his tutorial. Thank you Mr. Bean!  Please follow the instructions from Bean's slides and the R code listed there as well as the R code here:

Here is the updated R code snippets -
#Populate the list of sentiment words from Hu and Liu (http://www.cs.uic.edu/~liub/FBS/sentiment-analysis.html)

huliu.pwords <- scan('opinion-lexicon/positive-words.txt', what='character', comment.char=';')

huliu.nwords <- scan('opinion-lexicon/negative-words.txt', what='character', comment.char=';')

# Add some words

huliu.nwords <- c(huliu.nwords,'wtf','wait','waiting','epicfail', 'crash', 'bug', 'bugy', 'bugs', 'slow', 'lie')

#Remove some words

huliu.nwords <- huliu.nwords[!huliu.nwords=='sap']

huliu.nwords <- huliu.nwords[!huliu.nwords=='cloud']

#which('sap' %in% huliu.nwords)

twitterTag <- "@Netflix"

# Get 1500 tweets - an individual is only allowed to get 1500 tweets

 tweets <- searchTwitter(tag, n=1500)

  tweets.text <- laply(tweets,function(t)t$getText())

  sentimentScoreDF <- getSentimentScore(tweets.text)

  sentimentScoreDF$TwitterTag <- twitterTag

# Get rid of tweets that have zero score and seperate +ve from -ve tweets

sentimentScoreDF$posTweets <- as.numeric(sentimentScoreDF$SentimentScore >=1)

sentimentScoreDF$negTweets <- as.numeric(sentimentScoreDF$SentimentScore <=-1)

#Summarize finidings

summaryDF <- ddply(sentimentScoreDF,"TwitterTag", summarise, 

                 TotalTweetsFetched=length(SentimentScore),

                 PositiveTweets=sum(posTweets), NegativeTweets=sum(negTweets), 

                 AverageScore=round(mean(SentimentScore),3))

summaryDF$TotalTweets <- summaryDF$PositiveTweets + summaryDF$NegativeTweets

#Get Sentiment Score

summaryDF$Sentiment  <- round(summaryDF$PositiveTweets/summaryDF$TotalTweets, 2)

Saving the best for the last, here is a word cloud (also called tag cloud) for Netflix built in R-

I will be putting the R code up here for building a word cloud after scrubbing it.

Happy Analyzing!

Closing the loop on Pervasive Location Analytics - an enlightening personal journey for sure!

When I started working on Google Maps deal at SAP in February of this year, I had no clue where it will end and what is next once the deal is done. I fell in love with this Location Analytics/Geo Data Visualization topic, and turned it into an opportunity to discuss this topic and also generate excitement in various different camps along the way.

Five sessions spread across three continents, 200+ attendees,1000 views and numerous downloads later, this topic became more than just a personal interest. I met great people along the way and worked with very smart and driven people to co-present from the likes of Ryan from Centigon Solutions, Nimish from FreshDirect and Brendan from ThinkSmart Technologies. (See links to slides and session evaluation below)

A proud moment arrived this morning when an alert from SlideShare popped up indicating that this topic is hot on Facebook and as a result this topic is being put on SlideShare home page. Wow!


Pervasive Location Analytics: The Next Frontier to Fall in The Enterprise Software?

Session Evaluations Results

Thank you - my next two blogs will be presenting my thoughts on Moblie Analytics and Agile BI - two topics I have spent significant amount of time from strategy, market, customer, competition and product point of view.