In [ ]:
In [58]:
movies = read.table("../../data/hejtmy-ratings.csv", sep = ",", header = T, stringsAsFactors = F)
Check if everything is alright
In [ ]:
Now let's dive deep into fancy subsettings
We subset table by either using indices of rows that we want, or by providing a logical vector. Don't forget that if the length of the vector doesn't match nrow() then we might get weird results.
Let's start with the slow way and assign logical vectors to variable before subsetting.
In [59]:
table(movies$Title.type)
Documentary Feature Film Mini-Series TV Episode TV Series
4 515 1 2 28
In [60]:
TVseries_after2000 = (movies$Title.type == "TV Series") & (movies$Year > 2000) #parentheses are useless, just make conditions clear
sum(TVseries_after2000)
23
Simple way to count number of titles matching condition is by sum function. Sum usually takes integers or numberic variables, but R can "bump" logical TRUE-FALSE to 1-0 and therefore sum all thre true values.
Now that we have that vector we can easily subset movies with it.
In [61]:
hist(movies[TVseries_after2000,]$You.rated)
You can try as complex subsets as you want. Try following:
In [62]:
set.seed(666)
random20 = sample(c(T, F), size = nrow(movies), prob = c(0.1, 0.9), replace = T)
mean(movies[random20,]$You.rated)
6.49019607843137
More common are the function that deal with strings, as strings can be directly compared using ==, %in% etc. but can't use <> signs or other more fancy functions.
So if you need to extract all TV things or things that have TV word inside, you can use regex matching funcions - grep, grepl and simillar.
In [63]:
string = "TV series"
grepl("TV", string)
TRUE
Don't forget that it matches the string literally, so only the first of these two conditios work
In [64]:
if (grepl("V ser", string)){print("this one is good")}
if (grepl(" V ser", string)){print("this one is good as well")}
[1] "this one is good"
Now this naturally works for vectors as well
In [65]:
iBat = grepl("Batman", movies$Title)
sum(iBat)
movies[iBat,]
3
position const created modified description Title Title.type Directors You.rated IMDb.Rating Runtime..mins. Year Genres Num..Votes Release.Date..month.day.year. URL 10 10 tt0112462 Sat Jun 18 00:00:00 2016 NA NA Batman Forever Feature Film Joel Schumacher 4 5.4 121 1995 action, adventure, fantasy 190857 1995-06-09 http://www.imdb.com/title/tt0112462/ 11 11 tt0118688 Sat Jun 18 00:00:00 2016 NA NA Batman & Robin Feature Film Joel Schumacher 2 3.7 125 1997 action 189915 1997-06-12 http://www.imdb.com/title/tt0118688/ 97 97 tt0372784 Thu Jul 24 00:00:00 2014 NA NA Batman Begins Feature Film Christopher Nolan 8 8.3 140 2005 action, adventure 981394 2005-06-10 http://www.imdb.com/title/tt0372784/
Grepl uses regex expressions. If you don't know what these are, read up a bit :) Regex allows us to parse text to extract parts of titles or first names, html addresses etc. More on that i recoding variables. Nevertheless, we can for example extract all the movies that have number in their title
In [66]:
num_in_title = grepl("[0-9]", movies$Title)
movies[num_in_title,]
position const created modified description Title Title.type Directors You.rated IMDb.Rating Runtime..mins. Year Genres Num..Votes Release.Date..month.day.year. URL 6 6 tt0416449 Wed Jun 22 00:00:00 2016 NA NA 300 Feature Film Zack Snyder 8 7.7 117 2006 action, drama, fantasy, war 607390 2006-12-09 http://www.imdb.com/title/tt0416449/ 7 7 tt1608290 Mon Jun 20 00:00:00 2016 NA NA Zoolander 2 Feature Film Ben Stiller 6 4.8 102 2016 comedy 35091 2016-02-04 http://www.imdb.com/title/tt1608290/ 15 15 tt0103064 Thu Jan 28 00:00:00 2016 NA NA Terminator 2: Judgment Day Feature Film James Cameron 9 8.5 137 1991 action, sci_fi 745147 1991-07-01 http://www.imdb.com/title/tt0103064/ 45 45 tt0100403 Tue Jun 2 00:00:00 2015 NA NA Predator 2 Feature Film Stephen Hopkins 6 6.2 108 1990 action, horror, sci_fi 105525 1990-11-19 http://www.imdb.com/title/tt0100403/ 47 47 tt1136608 Mon Jun 1 00:00:00 2015 NA NA District 9 Feature Film Neill Blomkamp 7 8 112 2009 action, sci_fi, thriller 531866 2009-08-13 http://www.imdb.com/title/tt1136608/ 87 87 tt1646971 Sun Sep 7 00:00:00 2014 NA NA How to Train Your Dragon 2 Feature Film Dean DeBlois 6 7.9 102 2014 animation, action, adventure, comedy, family, fantasy 221229 2014-05-16 http://www.imdb.com/title/tt1646971/ 88 88 tt1335975 Sun Sep 7 00:00:00 2014 NA NA 47 Ronin Feature Film Carl Rinsch 4 6.3 128 2013 action, adventure, drama, fantasy 117035 2013-12-06 http://www.imdb.com/title/tt1335975/ 126 126 tt1229340 Tue Mar 18 00:00:00 2014 NA NA Anchorman 2: The Legend Continues Feature Film Adam McKay 7 6.3 119 2013 comedy 131282 2013-11-24 http://www.imdb.com/title/tt1229340/ 171 171 tt0481369 Sun Oct 27 00:00:00 2013 NA NA The Number 23 Feature Film Joel Schumacher 5 6.4 101 2007 mystery, thriller 164657 2007-02-13 http://www.imdb.com/title/tt0481369/ 179 179 tt1690953 Sat Oct 19 00:00:00 2013 NA NA Despicable Me 2 Feature Film Pierre Coffin, Chris Renaud 7 7.5 98 2013 animation, comedy, family, sci_fi 286983 2013-06-16 http://www.imdb.com/title/tt1690953/ 181 181 tt0486576 Sat Oct 19 00:00:00 2013 NA NA 4: Rise of the Silver Surfer Feature Film Tim Story 3 5.6 92 2007 action, adventure, sci_fi, thriller 213326 2007-06-12 http://www.imdb.com/title/tt0486576/ 201 201 tt1022603 Fri Oct 4 00:00:00 2013 NA NA (500) Days of Summer Feature Film Marc Webb 6 7.7 95 2009 comedy, drama, romance 376716 2009-01-17 http://www.imdb.com/title/tt1022603/ 209 209 tt0435761 Fri Oct 4 00:00:00 2013 NA NA Toy Story 3 Feature Film Lee Unkrich 7 8.3 103 2010 animation, adventure, comedy, family, fantasy 545099 2010-06-12 http://www.imdb.com/title/tt0435761/ 211 211 tt1409024 Fri Oct 4 00:00:00 2013 NA NA Men in Black 3 Feature Film Barry Sonnenfeld 7 6.8 106 2012 action, adventure, comedy, family, fantasy, sci_fi 268202 2012-05-14 http://www.imdb.com/title/tt1409024/ 240 240 tt0165832 Sun Jun 23 00:00:00 2013 NA NA Interstate 60: Episodes of the Road Feature Film Bob Gale 7 7.7 116 2002 adventure, comedy, drama, fantasy 23483 2002-04-13 http://www.imdb.com/title/tt0165832/ 246 246 tt1306980 Wed May 15 00:00:00 2013 NA NA 50/50 Feature Film Jonathan Levine 8 7.7 100 2011 comedy, drama, romance 270497 2011-09-12 http://www.imdb.com/title/tt1306980/ 280 280 tt0290334 Mon Feb 25 00:00:00 2013 NA NA X2 Feature Film Bryan Singer 7 7.5 134 2003 action, adventure, fantasy, sci_fi, thriller 406116 2003-04-24 http://www.imdb.com/title/tt0290334/ 286 286 tt0472033 Sun Feb 17 00:00:00 2013 NA NA 9 Feature Film Shane Acker 6 7.1 79 2009 animation, action, adventure, drama, mystery, sci_fi, thriller 111144 2009-08-19 http://www.imdb.com/title/tt0472033/ 358 358 tt0926084 Mon Oct 15 00:00:00 2012 NA NA Harry Potter and the Deathly Hallows: Part 1 Feature Film David Yates 6 7.7 146 2010 adventure, family, fantasy, mystery 328420 2010-11-11 http://www.imdb.com/title/tt0926084/ 376 376 tt0298148 Mon Oct 15 00:00:00 2012 NA NA Shrek 2 Feature Film Andrew Adamson, Kelly Asbury 8 7.2 93 2004 animation, adventure, comedy, family, fantasy, romance 314751 2004-05-15 http://www.imdb.com/title/tt0298148/ 385 385 tt1764651 Sat Oct 6 00:00:00 2012 NA NA The Expendables 2 Feature Film Simon West 7 6.7 103 2012 action, adventure, thriller 246865 2012-08-08 http://www.imdb.com/title/tt1764651/ 386 386 tt1302011 Sat Oct 6 00:00:00 2012 NA NA Kung Fu Panda 2 Feature Film Jennifer Yuh Nelson 9 7.3 90 2011 animation, action, adventure, comedy, family 182820 2011-05-22 http://www.imdb.com/title/tt1302011/ 387 387 tt0108525 Thu Oct 4 00:00:00 2012 NA NA Wayne's World 2 Feature Film Stephen Surjik 8 6.1 95 1993 comedy, music 62607 1993-12-10 http://www.imdb.com/title/tt0108525/ 399 399 tt1232829 Mon Jul 30 00:00:00 2012 NA NA 21 Jump Street Feature Film Phil Lord, Christopher Miller 6 7.2 109 2012 action, comedy, crime 408441 2012-03-12 http://www.imdb.com/title/tt1232829/ 416 416 tt0405422 Thu Jun 28 00:00:00 2012 NA NA The 40 Year Old Virgin Feature Film Judd Apatow 6 7.1 116 2005 comedy, romance 313897 2005-08-11 http://www.imdb.com/title/tt0405422/ 430 430 tt1228705 Mon May 7 00:00:00 2012 NA NA Iron Man 2 Feature Film Jon Favreau 7 7 124 2010 action, adventure, sci_fi 522610 2010-04-26 http://www.imdb.com/title/tt1228705/ 431 431 tt0050083 Mon May 7 00:00:00 2012 NA NA 12 Angry Men Feature Film Sidney Lumet 10 8.9 96 1957 crime, drama 447947 1957-04-10 http://www.imdb.com/title/tt0050083/ 477 477 tt0114369 Wed Nov 30 00:00:00 2011 NA NA Se7en Feature Film David Fincher 10 8.6 127 1995 crime, drama, mystery, thriller 1023912 1995-09-22 http://www.imdb.com/title/tt0114369/ 489 489 tt0062622 Wed Nov 30 00:00:00 2011 NA NA 2001: A Space Odyssey Feature Film Stanley Kubrick 6 8.3 149 1968 adventure, mystery, sci_fi 427516 1968-04-02 http://www.imdb.com/title/tt0062622/ 497 497 tt1650062 Tue Nov 29 00:00:00 2011 NA NA Super 8 Feature Film J.J. Abrams 7 7.1 112 2011 mystery, sci_fi, thriller 287921 2011-06-09 http://www.imdb.com/title/tt1650062/ 499 499 tt1201607 Mon Oct 31 00:00:00 2011 NA NA Harry Potter and the Deathly Hallows: Part 2 Feature Film David Yates 2 8.1 130 2011 adventure, drama, fantasy, mystery 542745 2011-07-07 http://www.imdb.com/title/tt1201607/ 504 504 tt0378194 Mon Oct 31 00:00:00 2011 NA NA Kill Bill: Vol. 2 Feature Film Quentin Tarantino 8 8 137 2004 action, crime, drama, thriller 512936 2004-04-16 http://www.imdb.com/title/tt0378194/ 518 518 tt0266697 Sat Oct 29 00:00:00 2011 NA NA Kill Bill: Vol. 1 Feature Film Quentin Tarantino 8 8.1 111 2003 action 736054 2003-10-10 http://www.imdb.com/title/tt0266697/ 546 546 tt0479952 Sat Oct 29 00:00:00 2011 NA NA Madagascar: Escape 2 Africa Feature Film Eric Darnell, Tom McGrath 6 6.7 89 2008 animation, action, adventure, comedy, family 146081 2008-10-30 http://www.imdb.com/title/tt0479952/
Well, we ca see that too many movies have number in the title just because they are a followup of another movie. So let's get rid of those
In [67]:
num_in_title = grepl("[4-9]", movies$Title)
mult_num_in_title = grepl("[0-9][0-9]", movies$Title)
movies[num_in_title | mult_num_in_title,]
position const created modified description Title Title.type Directors You.rated IMDb.Rating Runtime..mins. Year Genres Num..Votes Release.Date..month.day.year. URL 6 6 tt0416449 Wed Jun 22 00:00:00 2016 NA NA 300 Feature Film Zack Snyder 8 7.7 117 2006 action, drama, fantasy, war 607390 2006-12-09 http://www.imdb.com/title/tt0416449/ 47 47 tt1136608 Mon Jun 1 00:00:00 2015 NA NA District 9 Feature Film Neill Blomkamp 7 8 112 2009 action, sci_fi, thriller 531866 2009-08-13 http://www.imdb.com/title/tt1136608/ 88 88 tt1335975 Sun Sep 7 00:00:00 2014 NA NA 47 Ronin Feature Film Carl Rinsch 4 6.3 128 2013 action, adventure, drama, fantasy 117035 2013-12-06 http://www.imdb.com/title/tt1335975/ 171 171 tt0481369 Sun Oct 27 00:00:00 2013 NA NA The Number 23 Feature Film Joel Schumacher 5 6.4 101 2007 mystery, thriller 164657 2007-02-13 http://www.imdb.com/title/tt0481369/ 181 181 tt0486576 Sat Oct 19 00:00:00 2013 NA NA 4: Rise of the Silver Surfer Feature Film Tim Story 3 5.6 92 2007 action, adventure, sci_fi, thriller 213326 2007-06-12 http://www.imdb.com/title/tt0486576/ 201 201 tt1022603 Fri Oct 4 00:00:00 2013 NA NA (500) Days of Summer Feature Film Marc Webb 6 7.7 95 2009 comedy, drama, romance 376716 2009-01-17 http://www.imdb.com/title/tt1022603/ 240 240 tt0165832 Sun Jun 23 00:00:00 2013 NA NA Interstate 60: Episodes of the Road Feature Film Bob Gale 7 7.7 116 2002 adventure, comedy, drama, fantasy 23483 2002-04-13 http://www.imdb.com/title/tt0165832/ 246 246 tt1306980 Wed May 15 00:00:00 2013 NA NA 50/50 Feature Film Jonathan Levine 8 7.7 100 2011 comedy, drama, romance 270497 2011-09-12 http://www.imdb.com/title/tt1306980/ 286 286 tt0472033 Sun Feb 17 00:00:00 2013 NA NA 9 Feature Film Shane Acker 6 7.1 79 2009 animation, action, adventure, drama, mystery, sci_fi, thriller 111144 2009-08-19 http://www.imdb.com/title/tt0472033/ 399 399 tt1232829 Mon Jul 30 00:00:00 2012 NA NA 21 Jump Street Feature Film Phil Lord, Christopher Miller 6 7.2 109 2012 action, comedy, crime 408441 2012-03-12 http://www.imdb.com/title/tt1232829/ 416 416 tt0405422 Thu Jun 28 00:00:00 2012 NA NA The 40 Year Old Virgin Feature Film Judd Apatow 6 7.1 116 2005 comedy, romance 313897 2005-08-11 http://www.imdb.com/title/tt0405422/ 431 431 tt0050083 Mon May 7 00:00:00 2012 NA NA 12 Angry Men Feature Film Sidney Lumet 10 8.9 96 1957 crime, drama 447947 1957-04-10 http://www.imdb.com/title/tt0050083/ 477 477 tt0114369 Wed Nov 30 00:00:00 2011 NA NA Se7en Feature Film David Fincher 10 8.6 127 1995 crime, drama, mystery, thriller 1023912 1995-09-22 http://www.imdb.com/title/tt0114369/ 489 489 tt0062622 Wed Nov 30 00:00:00 2011 NA NA 2001: A Space Odyssey Feature Film Stanley Kubrick 6 8.3 149 1968 adventure, mystery, sci_fi 427516 1968-04-02 http://www.imdb.com/title/tt0062622/ 497 497 tt1650062 Tue Nov 29 00:00:00 2011 NA NA Super 8 Feature Film J.J. Abrams 7 7.1 112 2011 mystery, sci_fi, thriller 287921 2011-06-09 http://www.imdb.com/title/tt1650062/
Boring and useless? Possibly. But use this knowledge to tell me wha do I like more. Sci_fi or mystery movies?
In [ ]:
In [ ]:
In [ ]:
Content source: lab-code/R-for-non-programmers
Similar notebooks: