Altair

 

- import 

import altair as alt
import pandas as pd

 

- alt.Chart(data).mark_bar().encode() 바 그래프

source = pd.DataFrame({
    'a': ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I'],
    'b': [28, 55, 43, 91, 81, 53, 19, 87, 52]
})

alt.Chart(source).mark_bar().encode(
    x='a',
    y='b'
)

# y = "count()"로 하면 히스토그램이 됨

 

- alt.Chart(data).mark_point().encode()  스캐터

import altair as alt 
# Import data object from vega_datasets 
from vega_datasets import data 
  
# Selecting the data 
iris = data.iris() 
  
# Making the Scatter Plot 
alt.Chart(iris).mark_point().encode( 
    # Map the sepalLength to x-axis 
    x='sepalLength', 
    # Map the petalLength to y-axis 
    y='petalLength', 
    # Map the species to shape 
    shape='species'
    
    color='Origin'
)

 

- alt.Chart(data).mark_line().encode() 선

import numpy as np 
x = np.arange(100)
data = pd.DataFrame({"x": x, "sin(x)": np.sin(x / 5)})

alt.Chart(data).mark_line().encode(x="x", y="sin(x)")

# alt.Chart(data).mark_line(point= True).encode(x="x", y="sin(x)") 수행하면 점선 같이

 

 

- heatmap 

# Compute x^2 + y^2 across a 2D grid
x, y = np.meshgrid(range(-5, 5), range(-5, 5))
z = x**2 + y**2

# Convert this grid to columnar data expected by Altair
data = pd.DataFrame({"x": x.ravel(), "y": y.ravel(), "z": z.ravel()})

alt.Chart(data).mark_rect().encode(x="x:O", y="y:O", color="z:Q")

 

- alt.Chart(iowa).mark_area().encode() 면적 그리기

import altair as alt
from vega_datasets import data

iowa = data.iowa_electricity()

alt.Chart(iowa).mark_area().encode(x="year:T", y="net_generation:Q", color="source:N")

 

- 수평으로 두개의 서브 플롯

import altair as alt
from vega_datasets import data

iris = data.iris.url

chart1 = alt.Chart(iris).mark_point().encode(
    x='petalLength:Q',
    y='petalWidth:Q',
    color='species:N'
).properties(
    height=300,
    width=300
)

chart2 = alt.Chart(iris).mark_bar().encode(
    x='count()',
    y=alt.Y('petalWidth:Q', bin=alt.Bin(maxbins=30)),
    color='species:N'
).properties(
    height=300,
    width=100
)

chart1 | chart2
# | 로 합침

 

 

-수직으로 두개의 서브플롯 만들기

import altair as alt
from vega_datasets import data

source = data.sp500.url

brush = alt.selection(type='interval', encodings=['x'])

base = alt.Chart(source).mark_area().encode(
    x = 'date:T',
    y = 'price:Q'
).properties(
    width=600,
    height=200
)

upper = base.encode(
    alt.X('date:T', scale=alt.Scale(domain=brush))
)

lower = base.properties(
    height=60
).add_selection(brush)

alt.vconcat(upper, lower)

# vconcat으로 합침

 

- 2x2 subplot

import altair as alt
from vega_datasets import data
iris = data.iris.url

alt.Chart(iris).mark_point().encode(
    alt.X(alt.repeat("column"), type='quantitative'),
    alt.Y(alt.repeat("row"), type='quantitative'),
    color='species:N'
).properties(
    width=200,
    height=200
).repeat(
    row=['petalLength', 'petalWidth'],
    column=['sepalLength', 'sepalWidth']
).interactive()

 

참고코드

11.Bokeh & Altair -2.ipynb

0.48MB