#Kristen Sosulski
#April 6, 2018

#1.Set working directory
setwd("~/Dropbox/R_Fundamentals")
#2. Importing our data
library(readr)
march <- read_csv("march_madness.csv")
## Parsed with column specification:
## cols(
##   RANK = col_integer(),
##   PREVIOUS = col_integer(),
##   SCHOOL = col_character(),
##   CONFERENCE = col_character(),
##   RECORD = col_character(),
##   ROAD = col_character(),
##   NEUTRAL = col_character(),
##   HOME = col_character(),
##   `NON-DI` = col_character()
## )
#3.Viewing our data
march
## # A tibble: 349 x 9
##     RANK PREVIOUS SCHOOL   CONFERENCE  RECORD ROAD  NEUTRAL HOME  `NON-DI`
##    <int>    <int> <chr>    <chr>       <chr>  <chr> <chr>   <chr> <chr>   
##  1     1        2 Florida  Southeaste… 32-2   10-2  5- 0    17-0  0-0     
##  2     2        1 Arizona  Pac-12      30-4   8-3   4- 1    18-0  0-0     
##  3     3        3 Kansas   Big 12      24-9   5-6   4- 2    15-1  0-0     
##  4     4        4 Wichita… Missouri V… 34-0   12-0  5- 0    16-0  1-0     
##  5     5        5 Villano… Big East    28-4   10-2  3- 1    15-1  0-0     
##  6     6        6 Wiscons… Big Ten     26-7   8-3   4- 1    14-3  0-0     
##  7     7        8 Iowa St. Big 12      26-7   4-6   7- 0    15-1  0-0     
##  8     8       11 Virginia Atlantic C… 28-6   7-4   6- 0    15-2  0-0     
##  9     9        7 Duke     Atlantic C… 26-8   4-5   5- 3    17-0  0-0     
## 10    10       10 Creight… Big East    26-7   7-4   3- 3    16-0  0-0     
## # ... with 339 more rows
#4.Print the number of rows and columns
dim(march)
## [1] 349   9
#5.Print the column names
names(march)
## [1] "RANK"       "PREVIOUS"   "SCHOOL"     "CONFERENCE" "RECORD"    
## [6] "ROAD"       "NEUTRAL"    "HOME"       "NON-DI"
#6.Change my column names to lowercase
names(march) <- tolower(names(march))
names(march)
## [1] "rank"       "previous"   "school"     "conference" "record"    
## [6] "road"       "neutral"    "home"       "non-di"
#7.Explore variables types
str(march)
## Classes 'tbl_df', 'tbl' and 'data.frame':    349 obs. of  9 variables:
##  $ rank      : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ previous  : int  2 1 3 4 5 6 8 11 7 10 ...
##  $ school    : chr  "Florida" "Arizona" "Kansas" "Wichita St." ...
##  $ conference: chr  "Southeastern" "Pac-12" "Big 12" "Missouri Valley" ...
##  $ record    : chr  "32-2" "30-4" "24-9" "34-0" ...
##  $ road      : chr  "10-2" "8-3" "5-6" "12-0" ...
##  $ neutral   : chr  "5- 0" "4- 1" "4- 2" "5- 0" ...
##  $ home      : chr  "17-0" "18-0" "15-1" "16-0" ...
##  $ non-di    : chr  "0-0" "0-0" "0-0" "1-0" ...
##  - attr(*, "spec")=List of 2
##   ..$ cols   :List of 9
##   .. ..$ RANK      : list()
##   .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
##   .. ..$ PREVIOUS  : list()
##   .. .. ..- attr(*, "class")= chr  "collector_integer" "collector"
##   .. ..$ SCHOOL    : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ CONFERENCE: list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ RECORD    : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ ROAD      : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ NEUTRAL   : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ HOME      : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   .. ..$ NON-DI    : list()
##   .. .. ..- attr(*, "class")= chr  "collector_character" "collector"
##   ..$ default: list()
##   .. ..- attr(*, "class")= chr  "collector_guess" "collector"
##   ..- attr(*, "class")= chr "col_spec"
#8.How many different conferences are there?
### approach 1 casting as factor
march$conference <-as.factor(march$conference)
march$conference
##   [1] Southeastern            Pac-12                 
##   [3] Big 12                  Missouri Valley        
##   [5] Big East                Big Ten                
##   [7] Big 12                  Atlantic Coast         
##   [9] Atlantic Coast          Big East               
##  [11] Big Ten                 Mountain West          
##  [13] Atlantic 10             Pac-12                 
##  [15] Mountain West           Atlantic Coast         
##  [17] Southeastern            Big Ten                
##  [19] AAC                     West Coast             
##  [21] AAC                     AAC                    
##  [23] Atlantic 10             Big Ten                
##  [25] Atlantic Coast          Big 12                 
##  [27] Atlantic 10             Pac-12                 
##  [29] Atlantic 10             Big 12                 
##  [31] West Coast              Atlantic 10            
##  [33] Conference USA          Pac-12                 
##  [35] Summit                  Big 12                 
##  [37] AAC                     Mid-American           
##  [39] Atlantic Coast          Big East               
##  [41] Pac-12                  Southeastern           
##  [43] Atlantic 10             Pac-12                 
##  [45] Big 12                  Ivy                    
##  [47] Big East                Big Ten                
##  [49] Southeastern            Big Ten                
##  [51] Big 12                  Southland              
##  [53] AAC                     Atlantic Coast         
##  [55] Atlantic Coast          Big Ten                
##  [57] OVC                     Horizon                
##  [59] Metro Atlantic          Metro Atlantic         
##  [61] West Coast              Conference USA         
##  [63] Pac-12                  Conference USA         
##  [65] Colonial                Mid-American           
##  [67] West Coast              Big East               
##  [69] Big East                Big Ten                
##  [71] Western Athletic        Missouri Valley        
##  [73] Conference USA          Southeastern           
##  [75] Atlantic 10             Sun Belt               
##  [77] Southeastern            Atlantic Coast         
##  [79] Atlantic Coast          Pac-12                 
##  [81] Atlantic Sun            Mountain West          
##  [83] Southeastern            Patriot                
##  [85] Missouri Valley         Mid-American           
##  [87] Mid-American            Big 12                 
##  [89] Atlantic 10             Sun Belt               
##  [91] Horizon                 Big East               
##  [93] Mid-American            Southeastern           
##  [95] Colonial                Metro Atlantic         
##  [97] OVC                     Atlantic 10            
##  [99] Mid-Eastern             Pac-12                 
## [101] Big Ten                 America East           
## [103] Conference USA          Pac-12                 
## [105] Metro Atlantic          Mid-American           
## [107] Big West                Mountain West          
## [109] Missouri Valley         Atlantic Coast         
## [111] Big West                Southland              
## [113] Atlantic Coast          Big Ten                
## [115] Summit                  Mountain West          
## [117] Mountain West           Patriot                
## [119] Colonial                Southeastern           
## [121] Big 12                  Ivy                    
## [123] Big Ten                 Southeastern           
## [125] Sun Belt                Southern               
## [127] Patriot                 Big East               
## [129] Northeast               Ivy                    
## [131] Horizon                 Colonial               
## [133] West Coast              Missouri Valley        
## [135] Mountain West           Atlantic Coast         
## [137] Mountain West           Summit                 
## [139] Summit                  Southeastern           
## [141] OVC                     OVC                    
## [143] AAC                     Western Athletic       
## [145] Big Ten                 Atlantic Sun           
## [147] Ivy                     Southeastern           
## [149] Big Sky                 Big East               
## [151] Conference USA          Conference USA         
## [153] Southern                Big East               
## [155] Atlantic 10             West Coast             
## [157] Atlantic Coast          Southland              
## [159] West Coast              Big West               
## [161] Mid-American            Southern               
## [163] Atlantic Sun            Atlantic 10            
## [165] America East            Big West               
## [167] Patriot                 Big South              
## [169] Southeastern            Conference USA         
## [171] Southwestern            Big South              
## [173] Horizon                 Missouri Valley        
## [175] AAC                     Pac-12                 
## [177] Northeast               West Coast             
## [179] West Coast              Sun Belt               
## [181] Horizon                 Mountain West          
## [183] Big Sky                 Horizon                
## [185] America East            Northeast              
## [187] Sun Belt                Atlantic 10            
## [189] Northeast               Atlantic Sun           
## [191] Southland               AAC                    
## [193] Metro Atlantic          Mid-American           
## [195] Conference USA          Big South              
## [197] Big Sky                 Metro Atlantic         
## [199] Sun Belt                Missouri Valley        
## [201] Big South               Conference USA         
## [203] Western Athletic        Mid-Eastern            
## [205] Big Sky                 Atlantic Sun           
## [207] Atlantic Coast          Big West               
## [209] Atlantic Sun            West Coast             
## [211] Big South               Big 12                 
## [213] Mid-American            Missouri Valley        
## [215] OVC                     Conference USA         
## [217] Mid-American            Northeast              
## [219] Summit                  AAC                    
## [221] Southern                Colonial               
## [223] Conference USA          Pac-12                 
## [225] Mid-Eastern             Atlantic 10            
## [227] Mid-Eastern             Big Sky                
## [229] Ivy                     Horizon                
## [231] Metro Atlantic          AAC                    
## [233] Colonial                America East           
## [235] Patriot                 Patriot                
## [237] Horizon                 Western Athletic       
## [239] Southwestern            Big South              
## [241] Big South               Colonial               
## [243] Southern                Sun Belt               
## [245] Southeastern            Atlantic Coast         
## [247] Big Sky                 Southland              
## [249] Metro Atlantic          Mountain West          
## [251] Western Athletic        Big Sky                
## [253] Big West                Southwestern           
## [255] Summit                  Patriot                
## [257] OVC                     Patriot                
## [259] Western Athletic        Southland              
## [261] Mid-Eastern             Southland              
## [263] Big Sky                 Southwestern           
## [265] Missouri Valley         Ivy                    
## [267] Western Athletic        Big South              
## [269] Northeast               Conference USA         
## [271] Southwestern            Southland              
## [273] Mid-Eastern             Patriot                
## [275] Big Sky                 Conference USA         
## [277] Colonial                Mountain West          
## [279] Western Athletic        Sun Belt               
## [281] Colonial                Atlantic Sun           
## [283] America East            Ivy                    
## [285] Sun Belt                Big West               
## [287] Big Sky                 Missouri Valley        
## [289] Metro Atlantic          Summit                 
## [291] OVC                     Metro Atlantic         
## [293] Northeast               Mid-Eastern            
## [295] Mid-American            Southwestern           
## [297] Northeast               Northeast              
## [299] Conference USA          OVC                    
## [301] Southern                Metro Atlantic         
## [303] Southern                Southwestern           
## [305] OVC                     Conference USA         
## [307] Sun Belt                Division I Independents
## [309] Mid-American            Atlantic Sun           
## [311] Big South               Western Athletic       
## [313] Southern                Southwestern           
## [315] Horizon                 Big South              
## [317] OVC                     Southland              
## [319] Big West                OVC                    
## [321] Patriot                 Summit                 
## [323] Mid-Eastern             Atlantic Sun           
## [325] America East            Big West               
## [327] America East            Southland              
## [329] Mid-Eastern             America East           
## [331] Mid-Eastern             OVC                    
## [333] Atlantic Sun            Ivy                    
## [335] Southern                Mid-Eastern            
## [337] Big South               Northeast              
## [339] Southern                America East           
## [341] Southland               Southwestern           
## [343] Mid-Eastern             Southland              
## [345] Southern                Big Sky                
## [347] Mid-Eastern             Southwestern           
## [349] Big South              
## 33 Levels: AAC America East Atlantic 10 Atlantic Coast ... Western Athletic
length(levels(march$conference))
## [1] 33
nlevels(march$conference)
## [1] 33
### approach 2
unique(march$conference)
##  [1] Southeastern            Pac-12                 
##  [3] Big 12                  Missouri Valley        
##  [5] Big East                Big Ten                
##  [7] Atlantic Coast          Mountain West          
##  [9] Atlantic 10             AAC                    
## [11] West Coast              Conference USA         
## [13] Summit                  Mid-American           
## [15] Ivy                     Southland              
## [17] OVC                     Horizon                
## [19] Metro Atlantic          Colonial               
## [21] Western Athletic        Sun Belt               
## [23] Atlantic Sun            Patriot                
## [25] Mid-Eastern             America East           
## [27] Big West                Southern               
## [29] Northeast               Big Sky                
## [31] Big South               Southwestern           
## [33] Division I Independents
## 33 Levels: AAC America East Atlantic 10 Atlantic Coast ... Western Athletic
length(unique(march$conference))
## [1] 33
#9a. What is the difference in rank from previous
march$diff <-march$rank - march$previous
march
## # A tibble: 349 x 10
##     rank previous school   conference  record road  neutral home  `non-di`
##    <int>    <int> <chr>    <fct>       <chr>  <chr> <chr>   <chr> <chr>   
##  1     1        2 Florida  Southeaste… 32-2   10-2  5- 0    17-0  0-0     
##  2     2        1 Arizona  Pac-12      30-4   8-3   4- 1    18-0  0-0     
##  3     3        3 Kansas   Big 12      24-9   5-6   4- 2    15-1  0-0     
##  4     4        4 Wichita… Missouri V… 34-0   12-0  5- 0    16-0  1-0     
##  5     5        5 Villano… Big East    28-4   10-2  3- 1    15-1  0-0     
##  6     6        6 Wiscons… Big Ten     26-7   8-3   4- 1    14-3  0-0     
##  7     7        8 Iowa St. Big 12      26-7   4-6   7- 0    15-1  0-0     
##  8     8       11 Virginia Atlantic C… 28-6   7-4   6- 0    15-2  0-0     
##  9     9        7 Duke     Atlantic C… 26-8   4-5   5- 3    17-0  0-0     
## 10    10       10 Creight… Big East    26-7   7-4   3- 3    16-0  0-0     
## # ... with 339 more rows, and 1 more variable: diff <int>
#9b. Print a list of schools that have changed 3 or more places
march_subset <- subset (x=march, subset= abs(diff)>=3)