Files
JuliaForDataAnalysis/ch013.jl
2022-02-21 19:42:50 +01:00

132 lines
3.9 KiB
Julia

using CSV
using DataFrames
using DataFramesMeta
using Dates
import Downloads
using GLM
using Plots
using Random
using SHA
using Statistics
import ZipFile
url_zip = "https://stacks.stanford.edu/file/druid:yg821jf8611/" *
"yg821jf8611_ky_owensboro_2020_04_01.csv.zip"
local_zip = "owensboro.zip"
isfile(url_zip) || Downloads.download(url_zip, local_zip)
isfile(local_zip)
open(sha256, local_zip) == [0x14, 0x3b, 0x7d, 0x74,
0xbc, 0x15, 0x74, 0xc5,
0xf8, 0x42, 0xe0, 0x3f,
0x8f, 0x08, 0x88, 0xd5,
0xe2, 0xa8, 0x13, 0x24,
0xfd, 0x4e, 0xab, 0xde,
0x02, 0x89, 0xdd, 0x74,
0x3c, 0xb3, 0x5d, 0x56]
archive = ZipFile.Reader(local_zip)
owensboro = CSV.read(read(only(archive.files)), DataFrame;
missingstring="NA")
close(archive)
describe(owensboro, :nunique, :nmissing, :eltype)
agg_violation = @chain owensboro begin
@rselect(:violation = strip.(split(:violation, ";")))
flatten(:violation)
@rselect(:violation = contains(:violation, "SPEEDING") ? "SPEEDING" : :violation)
groupby(:violation)
combine(nrow)
sort!(:nrow, rev=true)
end
top_violation = first(agg_violation.violation, 4)
owensboro2 = select(owensboro,
:date => ByRow(dayofweek) => :day,
:type,
:arrest_made => :arrest,
:violation =>
ByRow(x -> contains.(x, top_violation)) =>
[:v_belt, :v_ins, :v_plate, :v_speed])
# mention rename and rename!
# Exercise:
# select(owensboro,
# :date => ByRow(dayname) => :day, :type, :arrest_made => :arrest,
# :violation => ByRow(x -> contains.(x, top_violation)) =>
# [:v_belt, :v_ins, :v_plate, :v_speed])
using CategoricalArrays
weekdays = DataFrame(day=1:7,
dayname=categorical(dayname.(1:7), ordered=true))
levels(weekdays.dayname)
levels!(weekdays.dayname, weekdays.dayname)
levels(weekdays.dayname)
leftjoin!(owensboro2, weekdays, on=:day)
levels(owensboro2.dayname)
@chain owensboro2 begin
groupby([:day, :dayname])
combine(nrow)
end
@chain owensboro2 begin
groupby([:day, :dayname])
combine(nrow)
unstack(:day, :dayname, :nrow)
end
# Alternative:
# unstack(owensboro2, :day, :dayname, :dayname, valuestransform=>length)
@chain owensboro2 begin
combine(AsTable(r"v_") => sum => :total)
groupby(:total)
combine(nrow)
end
select!(owensboro2, :arrest, :dayname, Not(:day))
mapcols(x -> count(ismissing, x), owensboro2)
dropmissing!(owensboro2)
mapcols(x -> count(ismissing, x), owensboro2)
@chain owensboro2 begin
groupby(:dayname, sort=true)
combine(:arrest => mean)
bar(_.dayname, _.arrest_mean, legend=false,
xlabel="day of week", ylabel="probability of arrest")
end
using Distributions
Random.seed!(1234);
owensboro2.train = rand(Bernoulli(0.7), nrow(owensboro2));
mean(owensboro2.train)
test, train = groupby(owensboro2, :train, sort=true);
model = glm(@formula(arrest~dayname+type+v_belt+v_ins+v_plate+v_speed),
train, Binomial(), LogitLink())
train.predict = predict(model);
test.predict = predict(model, test);
test_groups = groupby(test, :arrest)
histogram(test_groups[(false,)].predict;
bins=10, normalize=:probability,
fillalpha=0.5, label="false")
histogram!(test_groups[(true,)].predict;
bins=10, normalize=:probability,
fillalpha=0.5, label="true")
using ROCAnalysis
test_roc = roc(test, score=:predict, target=:arrest)
plot(test_roc.pfa, 1 .- test_roc.pmiss;
legend=:bottomright,
color="black", lw=3,
label="test (AUC=$(round(100*(1-auc(test_roc)), digits=2))%)",
xlabel="FPR", ylabel="TPR")
train_roc = roc(train, score=:predict, target=:arrest)
plot!(train_roc.pfa, 1 .- train_roc.pmiss;
color="green", lw=3,
label="train (AUC=$(round(100*(1-auc(train_roc)), digits=2))%)",)