1. Load data
## Student Astronomy Charms Herbology Defence.Against.the.Dark.Arts Potions
## 1 1 0 1 1 1 1
## 2 2 0 0 1 0 1
## 3 3 0 1 0 0 1
## 4 4 0 0 1 1 1
## 5 5 0 1 0 0 1
## 6 6 0 0 0 0 1
## History.of.Magic Transfiguration Flying Ancient.Runes Arithmancy
## 1 0 1 1 1 0
## 2 0 1 1 0 0
## 3 1 1 1 1 1
## 4 0 1 0 0 0
## 5 0 1 1 1 1
## 6 0 0 0 0 0
## Care.for.Magical.Creatures Divination Muggle.Studies Quidditch
## 1 0 0 0 1
## 2 1 1 0 0
## 3 1 1 1 0
## 4 1 0 0 1
## 5 0 1 1 0
## 6 0 0 0 1## [1] 1000## 'data.frame': 1000 obs. of 15 variables:
## $ Student : int 1 2 3 4 5 6 7 8 9 10 ...
## $ Astronomy : int 0 0 0 0 0 0 0 0 0 1 ...
## $ Charms : int 1 0 1 0 1 0 1 0 0 1 ...
## $ Herbology : int 1 1 0 1 0 0 1 1 0 1 ...
## $ Defence.Against.the.Dark.Arts: int 1 0 0 1 0 0 1 1 0 1 ...
## $ Potions : int 1 1 1 1 1 1 1 0 1 0 ...
## $ History.of.Magic : int 0 0 1 0 0 0 0 0 0 0 ...
## $ Transfiguration : int 1 1 1 1 1 0 1 1 0 0 ...
## $ Flying : int 1 1 1 0 1 0 1 0 0 0 ...
## $ Ancient.Runes : int 1 0 1 0 1 0 1 1 0 1 ...
## $ Arithmancy : int 0 0 1 0 1 0 1 1 0 1 ...
## $ Care.for.Magical.Creatures : int 0 1 1 1 0 0 1 0 1 0 ...
## $ Divination : int 0 1 1 0 1 0 1 1 0 0 ...
## $ Muggle.Studies : int 0 0 1 0 1 0 0 0 1 0 ...
## $ Quidditch : int 1 0 0 1 0 1 0 0 0 0 ...Remove the first column because that’s the student ID.
## Astronomy Charms Herbology Defence.Against.the.Dark.Arts Potions
## 1 0 1 1 1 1
## 2 0 0 1 0 1
## 3 0 1 0 0 1
## 4 0 0 1 1 1
## 5 0 1 0 0 1
## 6 0 0 0 0 1
## History.of.Magic Transfiguration Flying Ancient.Runes Arithmancy
## 1 0 1 1 1 0
## 2 0 1 1 0 0
## 3 1 1 1 1 1
## 4 0 1 0 0 0
## 5 0 1 1 1 1
## 6 0 0 0 0 0
## Care.for.Magical.Creatures Divination Muggle.Studies Quidditch
## 1 0 0 0 1
## 2 1 1 0 0
## 3 1 1 1 0
## 4 1 0 0 1
## 5 0 1 1 0
## 6 0 0 0 1## [1] "Astronomy" "Charms"
## [3] "Herbology" "Defence.Against.the.Dark.Arts"
## [5] "Potions" "History.of.Magic"
## [7] "Transfiguration" "Flying"
## [9] "Ancient.Runes" "Arithmancy"
## [11] "Care.for.Magical.Creatures" "Divination"
## [13] "Muggle.Studies" "Quidditch"2. Libraries
## Warning: package 'recommenderlab' was built under R version 3.6.3## Loading required package: Matrix## Loading required package: arules## Warning: package 'arules' was built under R version 3.6.3##
## Attaching package: 'arules'## The following objects are masked from 'package:base':
##
## abbreviate, write## Loading required package: proxy##
## Attaching package: 'proxy'## The following object is masked from 'package:Matrix':
##
## as.matrix## The following objects are masked from 'package:stats':
##
## as.dist, dist## The following object is masked from 'package:base':
##
## as.matrix## Loading required package: registry## Registered S3 methods overwritten by 'registry':
## method from
## print.registry_field proxy
## print.registry_entry proxy3. Summary data
## [1] "Astronomy" "Charms"
## [3] "Herbology" "Defence.Against.the.Dark.Arts"
## [5] "Potions" "History.of.Magic"
## [7] "Transfiguration" "Flying"
## [9] "Ancient.Runes" "Arithmancy"
## [11] "Care.for.Magical.Creatures" "Divination"
## [13] "Muggle.Studies" "Quidditch"hogwarts_1_tot <- colSums(hogwarts_1, na.rm = FALSE, dims = 1)
hogwarts_1_tot_df <- data.frame(t(hogwarts_1_tot))
hogwarts_1_tot_df## Astronomy Charms Herbology Defence.Against.the.Dark.Arts Potions
## 1 54 363 280 149 442
## History.of.Magic Transfiguration Flying Ancient.Runes Arithmancy
## 1 42 279 234 357 381
## Care.for.Magical.Creatures Divination Muggle.Studies Quidditch
## 1 536 490 322 4574. Convert to matrix
## [1] TRUE## [1] 10005. Convert to transactions
## transactions in sparse format with
## 1000 transactions (rows) and
## 14 items (columns)## Astronomy Charms
## 0.054 0.363
## Herbology Defence.Against.the.Dark.Arts
## 0.280 0.149
## Potions History.of.Magic
## 0.442 0.042
## Transfiguration Flying
## 0.279 0.234
## Ancient.Runes Arithmancy
## 0.357 0.381
## Care.for.Magical.Creatures Divination
## 0.536 0.490
## Muggle.Studies Quidditch
## 0.322 0.457
6. Association rules
hogwarts_1_m_trans_rules <- apriori(hogwarts_1_m_trans,
parameter = list(supp = 0.02, conf = 0.5,
target = "rules"))## Apriori
##
## Parameter specification:
## confidence minval smax arem aval originalSupport maxtime support minlen
## 0.5 0.1 1 none FALSE TRUE 5 0.02 1
## maxlen target ext
## 10 rules TRUE
##
## Algorithmic control:
## filter tree heap memopt load sort verbose
## 0.1 TRUE TRUE FALSE TRUE 2 TRUE
##
## Absolute minimum support count: 20
##
## set item appearances ...[0 item(s)] done [0.00s].
## set transactions ...[14 item(s), 1000 transaction(s)] done [0.00s].
## sorting and recoding items ... [14 item(s)] done [0.00s].
## creating transaction tree ... done [0.00s].
## checking subsets of size 1 2 3 4 5 6 7 8 done [0.00s].
## writing ... [4956 rule(s)] done [0.00s].
## creating S4 object ... done [0.00s].## set of 4956 rules## lhs rhs support confidence coverage lift count
## [1] {Herbology,
## Transfiguration,
## Flying,
## Ancient.Runes,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.025 0.9615385 0.026 6.453278 25
## [2] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Ancient.Runes,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.025 0.9615385 0.026 6.453278 25
## [3] {Herbology,
## Transfiguration,
## Flying,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.023 0.9583333 0.024 6.431767 23
## [4] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.022 0.9565217 0.023 6.419609 22
## [5] {Herbology,
## Transfiguration,
## Flying,
## Ancient.Runes,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.021 0.9545455 0.022 6.406345 21
## [6] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Ancient.Runes,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.021 0.9545455 0.022 6.406345 21
## [7] {Herbology,
## Transfiguration,
## Flying,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.038 0.9268293 0.041 6.220331 38
## [8] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.037 0.9250000 0.040 6.208054 37
## [9] {Charms,
## Herbology,
## Transfiguration,
## Flying,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.026 0.8965517 0.029 6.017126 26
## [10] {Charms,
## Herbology,
## Potions,
## Transfiguration,
## Flying,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.026 0.8965517 0.029 6.017126 26
## [11] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Ancient.Runes} => {Defence.Against.the.Dark.Arts} 0.032 0.8888889 0.036 5.965697 32
## [12] {Herbology,
## Potions,
## Transfiguration,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.031 0.8857143 0.035 5.944391 31
## [13] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Arithmancy} => {Defence.Against.the.Dark.Arts} 0.029 0.8787879 0.033 5.897905 29
## [14] {Herbology,
## Potions,
## Transfiguration,
## Ancient.Runes,
## Arithmancy,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.029 0.8787879 0.033 5.897905 29
## [15] {Herbology,
## Transfiguration,
## Flying} => {Defence.Against.the.Dark.Arts} 0.056 0.8750000 0.064 5.872483 56
## [16] {Herbology,
## Transfiguration,
## Flying,
## Ancient.Runes} => {Defence.Against.the.Dark.Arts} 0.035 0.8750000 0.040 5.872483 35
## [17] {Herbology,
## Potions,
## Transfiguration,
## Flying,
## Ancient.Runes,
## Arithmancy} => {Defence.Against.the.Dark.Arts} 0.028 0.8750000 0.032 5.872483 28
## [18] {Herbology,
## Transfiguration,
## Flying,
## Arithmancy} => {Defence.Against.the.Dark.Arts} 0.034 0.8717949 0.039 5.850972 34
## [19] {Herbology,
## Potions,
## Transfiguration,
## Ancient.Runes,
## Quidditch} => {Defence.Against.the.Dark.Arts} 0.034 0.8717949 0.039 5.850972 34
## [20] {Herbology,
## Potions,
## Transfiguration,
## Flying} => {Defence.Against.the.Dark.Arts} 0.047 0.8703704 0.054 5.841412 477. Interpretation
Interpreting the first 3 rules:
Rule 1: After taking Herbology, Transfiguration, Flying, Ancient Runes, and Quidditch, with 96.15% confidence, Defence Against the Dark Arts will also be taken this occurs 2.5% of the time. The lift ratio is 6.45 (much larger than 1.0), indicating strong association.
Rule 2: After taking Herbology, Potions, Transfiguration, Flying, Ancient Runes, and Quidditch, with 96.15% confidence, Defence Against the Dark Arts will also be taken this occurs 2.5% of the time. The lift ratio is 6.45 (much arger than 1.0), indicating strong association.
Rule 3: After taking Herbology, Transfiguration, Flying, Arithmancy, and Quidditch, with 96.15% confidence, Defence Against the Dark Arts will also be taken this occurs 2.5% of the time. The lift ratio is 6.45 (much arger than 1.0), indicating strong association.
The first 5 rules have similar support, confidence, and lift ratios. This indicates similarity in the users’ purchases.Incidentally, the top 20 rules all have a similar consequent, which is Defence Against the Dark Arts. Hence, regardless of the conbination of items purchased, Defence Against the Dark Arts is needed.
This is obvious, because He Who Shall Not Be Named is coming.
