Start by setting working directory

setwd("~/Desktop/NTHU/Spring 2024/courses/Social Network Analysis & Management/Week 7")

# Getting the whole data
library(readr)
library(igraph)
## 
## Attaching package: 'igraph'
## The following objects are masked from 'package:stats':
## 
##     decompose, spectrum
## The following object is masked from 'package:base':
## 
##     union
onlinefoods <- read_csv("onlinefoods.csv"); onlinefoods
## New names:
## • `` -> `...13`
## Rows: 388 Columns: 13
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (8): Gender, Marital Status, Occupation, Monthly Income, Educational Qua...
## dbl (5): Age, Family size, latitude, longitude, Pin code
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
## # A tibble: 388 × 13
##      Age Gender `Marital Status` Occupation `Monthly Income`
##    <dbl> <chr>  <chr>            <chr>      <chr>           
##  1    20 Female Single           Student    No Income       
##  2    24 Female Single           Student    Below Rs.10000  
##  3    22 Male   Single           Student    Below Rs.10000  
##  4    22 Female Single           Student    No Income       
##  5    22 Male   Single           Student    Below Rs.10000  
##  6    27 Female Married          Employee   More than 50000 
##  7    22 Male   Single           Student    No Income       
##  8    24 Female Single           Student    No Income       
##  9    23 Female Single           Student    No Income       
## 10    23 Female Single           Student    No Income       
## # ℹ 378 more rows
## # ℹ 8 more variables: `Educational Qualifications` <chr>, `Family size` <dbl>,
## #   latitude <dbl>, longitude <dbl>, `Pin code` <dbl>, Output <chr>,
## #   Feedback <chr>, ...13 <chr>

Showing the data of “Income” and “Family Size”

y <- data.frame(onlinefoods$`Monthly Income`, onlinefoods$`Family size`);y
##     onlinefoods..Monthly.Income. onlinefoods..Family.size.
## 1                      No Income                         4
## 2                 Below Rs.10000                         3
## 3                 Below Rs.10000                         3
## 4                      No Income                         6
## 5                 Below Rs.10000                         4
## 6                More than 50000                         2
## 7                      No Income                         3
## 8                      No Income                         3
## 9                      No Income                         2
## 10                     No Income                         4
## 11                     No Income                         5
## 12                Below Rs.10000                         2
## 13                     No Income                         5
## 14                     No Income                         4
## 15                10001 to 25000                         5
## 16                     No Income                         6
## 17                25001 to 50000                         2
## 18                     No Income                         3
## 19                     No Income                         4
## 20                Below Rs.10000                         1
## 21                     No Income                         3
## 22                     No Income                         4
## 23                     No Income                         4
## 24                     No Income                         4
## 25                Below Rs.10000                         3
## 26                     No Income                         3
## 27                     No Income                         5
## 28                     No Income                         3
## 29                10001 to 25000                         3
## 30                Below Rs.10000                         4
## 31                10001 to 25000                         5
## 32                     No Income                         4
## 33               More than 50000                         4
## 34                10001 to 25000                         5
## 35                     No Income                         2
## 36                10001 to 25000                         3
## 37                     No Income                         5
## 38                     No Income                         5
## 39                     No Income                         3
## 40                     No Income                         4
## 41               More than 50000                         4
## 42                     No Income                         3
## 43                     No Income                         4
## 44                     No Income                         5
## 45                     No Income                         5
## 46                10001 to 25000                         2
## 47                     No Income                         3
## 48                     No Income                         2
## 49                     No Income                         3
## 50                10001 to 25000                         5
## 51                     No Income                         5
## 52                     No Income                         2
## 53                     No Income                         3
## 54                     No Income                         2
## 55                     No Income                         3
## 56                     No Income                         2
## 57                     No Income                         1
## 58                     No Income                         3
## 59               More than 50000                         5
## 60                     No Income                         4
## 61                     No Income                         5
## 62                     No Income                         3
## 63                25001 to 50000                         1
## 64                     No Income                         4
## 65                     No Income                         2
## 66                     No Income                         6
## 67                10001 to 25000                         4
## 68                     No Income                         4
## 69                     No Income                         4
## 70               More than 50000                         4
## 71                     No Income                         4
## 72                10001 to 25000                         3
## 73                     No Income                         3
## 74                     No Income                         2
## 75                     No Income                         4
## 76                25001 to 50000                         3
## 77                     No Income                         4
## 78                     No Income                         4
## 79                     No Income                         3
## 80                     No Income                         5
## 81                10001 to 25000                         4
## 82                     No Income                         3
## 83                     No Income                         3
## 84                     No Income                         3
## 85                     No Income                         3
## 86                     No Income                         4
## 87                     No Income                         5
## 88                     No Income                         1
## 89                     No Income                         5
## 90                10001 to 25000                         2
## 91                25001 to 50000                         5
## 92                10001 to 25000                         1
## 93                     No Income                         2
## 94                     No Income                         3
## 95                     No Income                         1
## 96                     No Income                         1
## 97                     No Income                         5
## 98                     No Income                         5
## 99                25001 to 50000                         5
## 100                    No Income                         3
## 101               10001 to 25000                         3
## 102                    No Income                         2
## 103               10001 to 25000                         3
## 104                    No Income                         3
## 105               25001 to 50000                         2
## 106              More than 50000                         3
## 107              More than 50000                         2
## 108                    No Income                         1
## 109               Below Rs.10000                         2
## 110                    No Income                         5
## 111                    No Income                         4
## 112                    No Income                         1
## 113               Below Rs.10000                         2
## 114                    No Income                         5
## 115               10001 to 25000                         2
## 116               25001 to 50000                         4
## 117                    No Income                         5
## 118              More than 50000                         2
## 119               25001 to 50000                         5
## 120               25001 to 50000                         3
## 121              More than 50000                         5
## 122               25001 to 50000                         3
## 123               25001 to 50000                         3
## 124              More than 50000                         5
## 125              More than 50000                         6
## 126               25001 to 50000                         3
## 127                    No Income                         3
## 128                    No Income                         4
## 129                    No Income                         3
## 130                    No Income                         4
## 131              More than 50000                         3
## 132              More than 50000                         1
## 133                    No Income                         2
## 134                    No Income                         2
## 135                    No Income                         4
## 136               25001 to 50000                         2
## 137               25001 to 50000                         3
## 138              More than 50000                         5
## 139              More than 50000                         3
## 140               Below Rs.10000                         4
## 141                    No Income                         3
## 142                    No Income                         3
## 143               25001 to 50000                         2
## 144                    No Income                         5
## 145                    No Income                         3
## 146               10001 to 25000                         3
## 147              More than 50000                         3
## 148                    No Income                         4
## 149               10001 to 25000                         4
## 150                    No Income                         4
## 151              More than 50000                         3
## 152                    No Income                         4
## 153                    No Income                         2
## 154                    No Income                         2
## 155               10001 to 25000                         5
## 156                    No Income                         4
## 157               25001 to 50000                         3
## 158                    No Income                         3
## 159              More than 50000                         5
## 160                    No Income                         2
## 161                    No Income                         2
## 162              More than 50000                         3
## 163               10001 to 25000                         4
## 164               25001 to 50000                         3
## 165               25001 to 50000                         3
## 166              More than 50000                         4
## 167                    No Income                         5
## 168                    No Income                         5
## 169              More than 50000                         2
## 170                    No Income                         2
## 171                    No Income                         1
## 172               Below Rs.10000                         3
## 173               25001 to 50000                         1
## 174                    No Income                         3
## 175               Below Rs.10000                         2
## 176               10001 to 25000                         6
## 177                    No Income                         2
## 178              More than 50000                         3
## 179               Below Rs.10000                         1
## 180               25001 to 50000                         3
## 181              More than 50000                         3
## 182               Below Rs.10000                         3
## 183               25001 to 50000                         4
## 184                    No Income                         2
## 185                    No Income                         5
## 186              More than 50000                         1
## 187                    No Income                         2
## 188               10001 to 25000                         2
## 189               25001 to 50000                         2
## 190              More than 50000                         6
## 191                    No Income                         3
## 192               25001 to 50000                         2
## 193              More than 50000                         5
## 194               25001 to 50000                         2
## 195              More than 50000                         2
## 196                    No Income                         3
## 197                    No Income                         6
## 198              More than 50000                         6
## 199                    No Income                         6
## 200                    No Income                         2
## 201                    No Income                         2
## 202                    No Income                         5
## 203               25001 to 50000                         4
## 204              More than 50000                         4
## 205                    No Income                         3
## 206                    No Income                         2
## 207               25001 to 50000                         4
## 208                    No Income                         1
## 209              More than 50000                         2
## 210               25001 to 50000                         4
## 211               25001 to 50000                         6
## 212               10001 to 25000                         3
## 213                    No Income                         2
## 214                    No Income                         3
## 215               10001 to 25000                         4
## 216               10001 to 25000                         3
## 217               25001 to 50000                         5
## 218               10001 to 25000                         2
## 219                    No Income                         5
## 220               25001 to 50000                         3
## 221                    No Income                         1
## 222                    No Income                         2
## 223               10001 to 25000                         4
## 224              More than 50000                         5
## 225                    No Income                         2
## 226               10001 to 25000                         2
## 227                    No Income                         3
## 228                    No Income                         2
## 229               10001 to 25000                         5
## 230               25001 to 50000                         3
## 231              More than 50000                         6
## 232                    No Income                         5
## 233               25001 to 50000                         3
## 234              More than 50000                         2
## 235              More than 50000                         3
## 236               25001 to 50000                         3
## 237                    No Income                         3
## 238                    No Income                         2
## 239               25001 to 50000                         2
## 240                    No Income                         3
## 241              More than 50000                         6
## 242                    No Income                         2
## 243               25001 to 50000                         3
## 244                    No Income                         2
## 245              More than 50000                         1
## 246                    No Income                         3
## 247               Below Rs.10000                         6
## 248              More than 50000                         3
## 249               Below Rs.10000                         1
## 250               25001 to 50000                         2
## 251               25001 to 50000                         3
## 252                    No Income                         6
## 253                    No Income                         3
## 254               10001 to 25000                         2
## 255                    No Income                         6
## 256              More than 50000                         3
## 257                    No Income                         2
## 258               25001 to 50000                         6
## 259                    No Income                         3
## 260               25001 to 50000                         6
## 261              More than 50000                         6
## 262               25001 to 50000                         2
## 263                    No Income                         2
## 264               10001 to 25000                         3
## 265              More than 50000                         4
## 266               25001 to 50000                         2
## 267               10001 to 25000                         3
## 268               25001 to 50000                         2
## 269               25001 to 50000                         3
## 270               25001 to 50000                         2
## 271               10001 to 25000                         2
## 272               Below Rs.10000                         2
## 273               25001 to 50000                         3
## 274               10001 to 25000                         2
## 275                    No Income                         2
## 276                    No Income                         4
## 277              More than 50000                         3
## 278                    No Income                         2
## 279              More than 50000                         5
## 280               10001 to 25000                         4
## 281                    No Income                         6
## 282                    No Income                         2
## 283                    No Income                         4
## 284               25001 to 50000                         3
## 285               10001 to 25000                         2
## 286                    No Income                         2
## 287               10001 to 25000                         2
## 288               25001 to 50000                         5
## 289                    No Income                         3
## 290                    No Income                         2
## 291              More than 50000                         6
## 292               25001 to 50000                         3
## 293                    No Income                         5
## 294              More than 50000                         1
## 295               25001 to 50000                         3
## 296               Below Rs.10000                         5
## 297                    No Income                         3
## 298               10001 to 25000                         1
## 299               25001 to 50000                         2
## 300              More than 50000                         6
## 301               Below Rs.10000                         3
## 302                    No Income                         6
## 303               Below Rs.10000                         4
## 304              More than 50000                         2
## 305                    No Income                         3
## 306                    No Income                         3
## 307                    No Income                         2
## 308                    No Income                         4
## 309                    No Income                         5
## 310               Below Rs.10000                         2
## 311              More than 50000                         5
## 312                    No Income                         2
## 313               10001 to 25000                         2
## 314                    No Income                         3
## 315                    No Income                         2
## 316               10001 to 25000                         5
## 317               25001 to 50000                         3
## 318              More than 50000                         6
## 319                    No Income                         5
## 320               25001 to 50000                         3
## 321              More than 50000                         2
## 322              More than 50000                         3
## 323               25001 to 50000                         3
## 324                    No Income                         3
## 325                    No Income                         2
## 326               25001 to 50000                         2
## 327                    No Income                         3
## 328              More than 50000                         6
## 329                    No Income                         2
## 330               25001 to 50000                         4
## 331              More than 50000                         4
## 332                    No Income                         3
## 333                    No Income                         2
## 334               25001 to 50000                         4
## 335                    No Income                         1
## 336              More than 50000                         2
## 337               25001 to 50000                         4
## 338               25001 to 50000                         6
## 339               10001 to 25000                         3
## 340                    No Income                         2
## 341                    No Income                         3
## 342               10001 to 25000                         4
## 343               10001 to 25000                         3
## 344               25001 to 50000                         5
## 345               10001 to 25000                         2
## 346               25001 to 50000                         4
## 347              More than 50000                         4
## 348                    No Income                         3
## 349                    No Income                         2
## 350               25001 to 50000                         4
## 351                    No Income                         1
## 352              More than 50000                         2
## 353               25001 to 50000                         4
## 354               25001 to 50000                         6
## 355               10001 to 25000                         3
## 356                    No Income                         2
## 357                    No Income                         2
## 358               10001 to 25000                         5
## 359               25001 to 50000                         3
## 360              More than 50000                         6
## 361                    No Income                         5
## 362               25001 to 50000                         3
## 363              More than 50000                         2
## 364              More than 50000                         3
## 365               25001 to 50000                         3
## 366                    No Income                         3
## 367                    No Income                         2
## 368               25001 to 50000                         2
## 369                    No Income                         3
## 370              More than 50000                         6
## 371                    No Income                         2
## 372               25001 to 50000                         3
## 373                    No Income                         2
## 374              More than 50000                         1
## 375                    No Income                         3
## 376               Below Rs.10000                         6
## 377              More than 50000                         3
## 378               Below Rs.10000                         1
## 379               25001 to 50000                         2
## 380               Below Rs.10000                         4
## 381              More than 50000                         2
## 382                    No Income                         3
## 383                    No Income                         3
## 384                    No Income                         2
## 385                    No Income                         4
## 386                    No Income                         5
## 387               Below Rs.10000                         2
## 388                    No Income                         5

The data shows there are 11 vertices and 388 edges:

net <- graph_from_data_frame(y, directed=T)
V(net)
## + 11/11 vertices, named, from 5b805b1:
##  [1] No Income       Below Rs.10000  More than 50000 10001 to 25000 
##  [5] 25001 to 50000  4               3               6              
##  [9] 2               5               1
E(net)
## + 388/388 edges from 5b805b1 (vertex names):
##  [1] No Income      ->4 Below Rs.10000 ->3 Below Rs.10000 ->3 No Income      ->6
##  [5] Below Rs.10000 ->4 More than 50000->2 No Income      ->3 No Income      ->3
##  [9] No Income      ->2 No Income      ->4 No Income      ->5 Below Rs.10000 ->2
## [13] No Income      ->5 No Income      ->4 10001 to 25000 ->5 No Income      ->6
## [17] 25001 to 50000 ->2 No Income      ->3 No Income      ->4 Below Rs.10000 ->1
## [21] No Income      ->3 No Income      ->4 No Income      ->4 No Income      ->4
## [25] Below Rs.10000 ->3 No Income      ->3 No Income      ->5 No Income      ->3
## [29] 10001 to 25000 ->3 Below Rs.10000 ->4 10001 to 25000 ->5 No Income      ->4
## [33] More than 50000->4 10001 to 25000 ->5 No Income      ->2 10001 to 25000 ->3
## [37] No Income      ->5 No Income      ->5 No Income      ->3 No Income      ->4
## + ... omitted several edges
V(net)$label <- V(net)$name
V(net)$degree <- degree(net)

Histogram of node degree

The result: Around 4 nodes with the range between 0 to 100 degree and some nodes with high degree (150 to 200 connections) also. It indicates that many nodes with few connections and few nodes with many connections.

hist(V(net)$degree,
     col = 'green',
     main = 'Histogram of Node Degree',
     ylab = 'Frequency',
     xlab = 'Degree of Vertices')

Network diagram

set.seed(222)
plot(net,
     vertex.color = 'green',
     vertext.size = 2,
     edge.arrow.size = 0.1,
     vertex.label.cex = 0.8,
     main = "Network diagram")

Highlighting degrees & layouts

The result: “No Income” is the highest degree followed by others.

plot(net,
     vertex.color = rainbow(52),
     vertex.size = V(net)$degree*0.4,
     edge.arrow.size = 0.1,
     layout=layout.fruchterman.reingold)

Degree of Network

The number of its adjacent edges

degree(net)
##       No Income  Below Rs.10000 More than 50000  10001 to 25000  25001 to 50000 
##             187              25              62              45              69 
##               4               3               6               2               5 
##              63             117              29             101              54 
##               1 
##              24

Diameter

Indicates the length of the longest geodesic

diameter(net, directed = F, weights = NA)
## [1] 2

Graph density

Shows the largest possible number of edges in the graph

edge_density(net)
## [1] 3.527273

Closeness

Show how many steps is required to access every other vertex from a given vertex

closeness(net, mode = "all", weights = NA)
##       No Income  Below Rs.10000 More than 50000  10001 to 25000  25001 to 50000 
##      0.07142857      0.07142857      0.07142857      0.07142857      0.07142857 
##               4               3               6               2               5 
##      0.06666667      0.06666667      0.06666667      0.06666667      0.06666667 
##               1 
##      0.06666667

Betweenness

A measure of centrality in a graph based on shortest paths

betweenness(net, directed = T, weights = NA)
##       No Income  Below Rs.10000 More than 50000  10001 to 25000  25001 to 50000 
##               0               0               0               0               0 
##               4               3               6               2               5 
##               0               0               0               0               0 
##               1 
##               0

Edge betweenness centrality

max() shows the maximum of Edge betweenness value min() shows the minimum of Edge betweenness value

edge_betweenness(net)
##   [1] 0.03225806 0.16666667 0.16666667 0.11111111 0.20000000 0.07692308
##   [7] 0.01818182 0.01818182 0.01960784 0.03225806 0.03333333 0.14285714
##  [13] 0.03333333 0.03225806 0.12500000 0.11111111 0.05882353 0.01818182
##  [19] 0.03225806 0.25000000 0.01818182 0.03225806 0.03225806 0.03225806
##  [25] 0.16666667 0.01818182 0.03333333 0.01818182 0.07692308 0.20000000
##  [31] 0.12500000 0.03225806 0.12500000 0.12500000 0.01960784 0.07692308
##  [37] 0.03333333 0.03333333 0.01818182 0.03225806 0.12500000 0.01818182
##  [43] 0.03225806 0.03333333 0.03333333 0.07692308 0.01818182 0.01960784
##  [49] 0.01818182 0.12500000 0.03333333 0.01960784 0.01818182 0.01960784
##  [55] 0.01818182 0.01960784 0.09090909 0.01818182 0.11111111 0.03225806
##  [61] 0.03333333 0.01818182 0.50000000 0.03225806 0.01960784 0.11111111
##  [67] 0.12500000 0.03225806 0.03225806 0.12500000 0.03225806 0.07692308
##  [73] 0.01818182 0.01960784 0.03225806 0.03571429 0.03225806 0.03225806
##  [79] 0.01818182 0.03333333 0.12500000 0.01818182 0.01818182 0.01818182
##  [85] 0.01818182 0.03225806 0.03333333 0.09090909 0.03333333 0.07692308
##  [91] 0.16666667 0.50000000 0.01960784 0.01818182 0.09090909 0.09090909
##  [97] 0.03333333 0.03333333 0.16666667 0.01818182 0.07692308 0.01960784
## [103] 0.07692308 0.01818182 0.05882353 0.06666667 0.07692308 0.09090909
## [109] 0.14285714 0.03333333 0.03225806 0.09090909 0.14285714 0.03333333
## [115] 0.07692308 0.09090909 0.03333333 0.07692308 0.16666667 0.03571429
## [121] 0.11111111 0.03571429 0.03571429 0.11111111 0.08333333 0.03571429
## [127] 0.01818182 0.03225806 0.01818182 0.03225806 0.06666667 0.20000000
## [133] 0.01960784 0.01960784 0.03225806 0.05882353 0.03571429 0.11111111
## [139] 0.06666667 0.20000000 0.01818182 0.01818182 0.05882353 0.03333333
## [145] 0.01818182 0.07692308 0.06666667 0.03225806 0.12500000 0.03225806
## [151] 0.06666667 0.03225806 0.01960784 0.01960784 0.12500000 0.03225806
## [157] 0.03571429 0.01818182 0.11111111 0.01960784 0.01960784 0.06666667
## [163] 0.12500000 0.03571429 0.03571429 0.12500000 0.03333333 0.03333333
## [169] 0.07692308 0.01960784 0.09090909 0.16666667 0.50000000 0.01818182
## [175] 0.14285714 1.00000000 0.01960784 0.06666667 0.25000000 0.03571429
## [181] 0.06666667 0.16666667 0.09090909 0.01960784 0.03333333 0.20000000
## [187] 0.01960784 0.07692308 0.05882353 0.08333333 0.01818182 0.05882353
## [193] 0.11111111 0.05882353 0.07692308 0.01818182 0.11111111 0.08333333
## [199] 0.11111111 0.01960784 0.01960784 0.03333333 0.09090909 0.12500000
## [205] 0.01818182 0.01960784 0.09090909 0.09090909 0.07692308 0.09090909
## [211] 0.20000000 0.07692308 0.01960784 0.01818182 0.12500000 0.07692308
## [217] 0.16666667 0.07692308 0.03333333 0.03571429 0.09090909 0.01960784
## [223] 0.12500000 0.11111111 0.01960784 0.07692308 0.01818182 0.01960784
## [229] 0.12500000 0.03571429 0.08333333 0.03333333 0.03571429 0.07692308
## [235] 0.06666667 0.03571429 0.01818182 0.01960784 0.05882353 0.01818182
## [241] 0.08333333 0.01960784 0.03571429 0.01960784 0.20000000 0.01818182
## [247] 0.50000000 0.06666667 0.25000000 0.05882353 0.03571429 0.11111111
## [253] 0.01818182 0.07692308 0.11111111 0.06666667 0.01960784 0.20000000
## [259] 0.01818182 0.20000000 0.08333333 0.05882353 0.01960784 0.07692308
## [265] 0.12500000 0.05882353 0.07692308 0.05882353 0.03571429 0.05882353
## [271] 0.07692308 0.14285714 0.03571429 0.07692308 0.01960784 0.03225806
## [277] 0.06666667 0.01960784 0.11111111 0.12500000 0.11111111 0.01960784
## [283] 0.03225806 0.03571429 0.07692308 0.01960784 0.07692308 0.16666667
## [289] 0.01818182 0.01960784 0.08333333 0.03571429 0.03333333 0.20000000
## [295] 0.03571429 1.00000000 0.01818182 0.50000000 0.05882353 0.08333333
## [301] 0.16666667 0.11111111 0.20000000 0.07692308 0.01818182 0.01818182
## [307] 0.01960784 0.03225806 0.03333333 0.14285714 0.11111111 0.01960784
## [313] 0.07692308 0.01818182 0.01960784 0.12500000 0.03571429 0.08333333
## [319] 0.03333333 0.03571429 0.07692308 0.06666667 0.03571429 0.01818182
## [325] 0.01960784 0.05882353 0.01818182 0.08333333 0.01960784 0.09090909
## [331] 0.12500000 0.01818182 0.01960784 0.09090909 0.09090909 0.07692308
## [337] 0.09090909 0.20000000 0.07692308 0.01960784 0.01818182 0.12500000
## [343] 0.07692308 0.16666667 0.07692308 0.09090909 0.12500000 0.01818182
## [349] 0.01960784 0.09090909 0.09090909 0.07692308 0.09090909 0.20000000
## [355] 0.07692308 0.01960784 0.01960784 0.12500000 0.03571429 0.08333333
## [361] 0.03333333 0.03571429 0.07692308 0.06666667 0.03571429 0.01818182
## [367] 0.01960784 0.05882353 0.01818182 0.08333333 0.01960784 0.03571429
## [373] 0.01960784 0.20000000 0.01818182 0.50000000 0.06666667 0.25000000
## [379] 0.05882353 0.20000000 0.07692308 0.01818182 0.01818182 0.01960784
## [385] 0.03225806 0.03333333 0.14285714 0.03333333
max(edge_betweenness(net))
## [1] 1
min(edge_betweenness(net)) 
## [1] 0.01818182