JuliaForDataAnalysis/ch08.jl
2022-11-10 13:10:39 +01:00

151 lines
3.0 KiB
Julia

# Bogumił Kamiński, 2022
# Codes for chapter 8
# Code for section 8.1
import Downloads
if isfile("new_puzzles.csv.bz2")
@info "file already present"
else
@info "fetching file"
Downloads.download("https://database.lichess.org/" *
"lichess_db_puzzle.csv.bz2",
"new_puzzles.csv.bz2")
end
using CodecBzip2
compressed = read("puzzles.csv.bz2")
plain = transcode(Bzip2Decompressor, compressed)
length(plain) / length(compressed)
open("puzzles.csv", "w") do io
println(io, "PuzzleId,FEN,Moves,Rating,RatingDeviation," *
"Popularity,NbPlays,Themes,GameUrl")
write(io, plain)
end
readlines("puzzles.csv")
# Code for section 8.2
using CSV
using DataFrames
puzzles = CSV.read("puzzles.csv", DataFrame);
puzzles2 = CSV.read(plain, DataFrame;
header=["PuzzleId", "FEN", "Moves",
"Rating", "RatingDeviation",
"Popularity", "NbPlays",
"Themes", "GameUrl"]);
puzzles == puzzles2
compressed = nothing
plain = nothing
# Code for listing 8.1
puzzles
# Code for listing 8.2
show(describe(puzzles); truncate=14)
# Code for getting basic information about a data frame
ncol(puzzles)
nrow(puzzles)
names(puzzles)
CSV.write("puzzles2.csv", puzzles)
read("puzzles2.csv")
read("puzzles2.csv") == read("puzzles.csv")
# Code for section 8.3
puzzles.Rating
using BenchmarkTools
@btime $puzzles.Rating;
puzzles.Rating == copy(puzzles.Rating)
puzzles.Rating === copy(puzzles.Rating)
puzzles.Rating === puzzles.Rating
copy(puzzles.Rating) === copy(puzzles.Rating)
puzzles."Rating"
col = "Rating"
# data_frame_name[selected_rows, selected_columns]
puzzles[:, "Rating"]
puzzles[:, :Rating]
puzzles[:, 4]
puzzles[:, col]
columnindex(puzzles, "Rating")
columnindex(puzzles, "Some fancy column name")
hasproperty(puzzles, "Rating")
hasproperty(puzzles, "Some fancy column name")
@btime $puzzles[:, :Rating];
puzzles[!, "Rating"]
puzzles[!, :Rating]
puzzles[!, 4]
puzzles[!, col]
using Plots
plot(histogram(puzzles.Rating, label="Rating"),
histogram(puzzles.RatingDeviation, label="RatingDeviation"),
histogram(puzzles.Popularity, label="Popularity"),
histogram(puzzles.NbPlays, label="NbPlays"))
plot([histogram(puzzles[!, col]; label=col) for
col in ["Rating", "RatingDeviation",
"Popularity", "NbPlays"]]...)
# Code for section 8.4
# Codes for Arrow examples
using Arrow
Arrow.write("puzzles.arrow", puzzles)
arrow_table = Arrow.Table("puzzles.arrow")
puzzles_arrow = DataFrame(arrow_table);
puzzles_arrow == puzzles
puzzles_arrow.PuzzleId
puzzles_arrow.PuzzleId[1] = "newID"
puzzles_arrow = copy(puzzles_arrow);
puzzles_arrow.PuzzleId
# Codes for SQLite examples
using SQLite
db = SQLite.DB("puzzles.db")
SQLite.load!(puzzles, db, "puzzles")
SQLite.tables(db)
SQLite.columns(db, "puzzles")
query = DBInterface.execute(db, "SELECT * FROM puzzles")
puzzles_db = DataFrame(query);
puzzles_db == puzzles
puzzles_db.PuzzleId
close(db)