JuliaForDataAnalysis/ch11.jl
2022-04-19 13:51:42 +02:00

156 lines
2.6 KiB
Julia

# Bogumił Kamiński, 2022
# Codes for chapter 11
# Code for section 11.1
# deserialization of source data frame
using DataFrames
using Serialization
walk = deserialize("walk.bin")
# Code for a note on conversion
x = [1.5]
x[1] = 1
x
# Code for section 11.1.1
Matrix(walk)
Matrix{Any}(walk)
Matrix{String}(walk)
using Plots
plot(walk)
plot(Matrix(walk); labels=["x" "y"] , legend=:topleft)
# Code for section 11.1.2
Tables.columntable(walk)
using BenchmarkTools
function mysum(table)
s = 0 #A
for v in table.x #B
s += v
end
return s
end
df = DataFrame(x=1:1_000_000);
@btime mysum($df)
tab = Tables.columntable(df);
@btime mysum($tab)
@code_warntype mysum(df)
@code_warntype mysum(tab)
typeof(tab)
function barrier_mysum2(x)
s = 0
for v in x
s += v
end
return s
end
mysum2(table) = barrier_mysum2(table.x)
@btime mysum2($df)
df = DataFrame(a=[1, 1, 2], b=[1, 1, 2])
unique(df)
tab = Tables.columntable(df)
unique(tab)
# Code for section 11.1.3
Tables.rowtable(walk)
nti = Tables.namedtupleiterator(walk)
for v in nti
println(v)
end
er = eachrow(walk)
er[1]
er[end]
ec = eachcol(walk)
ec[1]
ec[end]
identity.(eachcol(walk))
df = DataFrame(x=1:2, b=["a", "b"])
identity.(eachcol(df))
# Code for section 11.2
using CSV
raw_data = """
city,date,rainfall
Olecko,2020-11-16,2.9
Olecko,2020-11-17,4.1
Olecko,2020-11-19,4.3
Olecko,2020-11-20,2.0
Olecko,2020-11-21,0.6
Olecko,2020-11-22,1.0
Ełk,2020-11-16,3.9
Ełk,2020-11-19,1.2
Ełk,2020-11-20,2.0
Ełk,2020-11-22,2.0
""";
rainfall_df = CSV.read(IOBuffer(raw_data), DataFrame)
gdf_city = groupby(rainfall_df, "city")
gdf_city_date = groupby(rainfall_df, Not("rainfall"))
keys(gdf_city_date)
gk1 = keys(gdf_city_date)[1]
g1_t = Tuple(gk1)
g1_nt = NamedTuple(gk1)
g1_dict = Dict(gk1)
gdf_city_date[1]
gdf_city_date[gk1]
gdf_city_date[g1_t]
gdf_city_date[g1_nt]
gdf_city_date[g1_dict]
gdf_city[("Olecko",)]
gdf_city[(city="Olecko",)]
using BenchmarkTools
bench_df = DataFrame(id=1:10^8);
bench_gdf = groupby(bench_df, :id);
@btime groupby($bench_df, :id);
bench_i = 1_000_000;
bench_gk = keys(bench_gdf)[bench_i];
bench_t = Tuple(bench_gk);
bench_nt = NamedTuple(bench_gk);
bench_dict = Dict(bench_gk);
@btime $bench_gdf[$bench_i];
@btime $bench_gdf[$bench_gk];
@btime $bench_gdf[$bench_t];
@btime $bench_gdf[$bench_nt];
@btime $bench_gdf[$bench_dict];
gdf_city[[2, 1]]
gdf_city[[1]]
[nrow(df) for df in gdf_city]
for p in pairs(gdf_city)
println(p)
end
Dict(key.city => nrow(df) for (key, df) in pairs(gdf_city))
combine(gdf_city, nrow)