Plotly: 如何更改子图y轴的范围？

Question

我有以下代码：

from plotly.subplots import make_subplots
import requests 
import json
import datetime as dt
import pandas as pd
import plotly.graph_objects as go




def get_candles(symbol, window, interval='1h'):
    url = "https://api.binance.com/api/v1/klines"
    end_time = dt.datetime.utcnow()
    delta = dt.timedelta(hours = window)
    start_time = end_time - delta
    start_date = str(int(start_time.timestamp() * 1000))
    end_date = str(int(end_time.timestamp() * 1000))
    limit = '1000'
    market = symbol + 'BUSD'

    req_param = {"symbol": market, "interval": interval, "startTime": start_date, "endTime": end_date, "limit": limit}

    text = requests.get(url, params = req_param).text
    data = json.loads(text)
    df = pd.DataFrame(data)
    df.columns = ['open_time',
                    'o', 'h', 'l', 'c', 'v',
                    'close_time', 'qav', 'num_trades',
                    'taker_base_vol', 'taker_quote_vol', 'ignore']

    df.index = [dt.datetime.fromtimestamp(x/1000.0) for x in df.close_time]

    return df


def chart(symbol, interval='1h'):
    windows = {'1m': 1, '5m': 5, '15m': 15, '30m': 30, '1h': 60, '2h': 120, '4h': 240, '6h': 360, '12h': 720, '1d': 1440}
    chart = get_candles(symbol.upper(), windows[interval], interval)
    fig = make_subplots(specs=[[{"secondary_y": True}]])
    print(chart['v'].max())
    fig.add_trace(go.Candlestick(x=chart.index,
            open=chart['o'],
            high=chart['h'],
            low=chart['l'],
            close=chart['c'],
            name="yaxis1 data",
            yaxis='y1'), secondary_y=True)
    fig.add_trace(go.Bar(x=chart.index, y=chart['v'], name="yaxis2 data", yaxis="y2"), secondary_y=False)
    fig.layout.yaxis2.showgrid=False
    fig.update_yaxes(type="linear")
    fig.update_layout(xaxis_rangeslider_visible=False)
    
    # fig.show()

    fig.write_image("figure.png", engine="kaleido")
    
chart('bnb')

它生成以下图像：

现在我想让音量条只到图表总高度的1/3，我尝试这样做：

fig.update_layout(yaxis1=dict(title="bars", domain=[0, int(2* chart['v'].max()/3)]))

但这没有任何效果。

如何为某个y轴指定名称并更改其范围？

- Mathijs van den Doel

Answer 1

这就是方法：

fig.update_layout(yaxis2 = dict(range=[<from_value>, <to_value>]))

你的代码样例在我的环境下无法工作。但是在这个例子中，以下设置：

fig.update_layout(yaxis2 = dict(range=[0, 300*10**6]))

...会将这个:

...变成这个:

完整代码：

import plotly.graph_objects as go
from plotly.subplots import make_subplots
import pandas as pd

# data
df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/finance-charts-apple.csv')

# Create figure with secondary y-axis
fig = make_subplots(specs=[[{"secondary_y": True}]])

# include candlestick with rangeselector
fig.add_trace(go.Candlestick(x=df['Date'],
                open=df['AAPL.Open'], high=df['AAPL.High'],
                low=df['AAPL.Low'], close=df['AAPL.Close']),
               secondary_y=False)

# include a go.Bar trace for volumes
fig.add_trace(go.Bar(x=df['Date'], y=df['AAPL.Volume']),
               secondary_y=True)
f = fig.full_figure_for_development(warn=False)

fig.layout.yaxis2.showgrid=False
fig.update_layout(yaxis2 = dict(range=[0, 300*10**6]))
fig.show()

- vestland

Answer 2

我遇到了类似的问题，但是上面的答案并没有帮助，因为我的图表是动态的。根据时间范围，最大交易量可以从300到1000万不等，所以固定范围不好用。

看起来最好的解决方案是使用max()函数在我的数据框架（也是动态的）的交易量列中找到最高值：

maxVol = max(df['Volume'], key=float)
ymax = float(maxVol)
print(ymax)

然后只需使用以下方法将最大范围按3倍比例缩放

fig.update_layout(yaxis=dict(range=[0, ymax*3]))

- Matthew Banham

Answer 3

我不使用plotly，但是查看文档后，我发现以下内容可以设置y轴的范围：

Code: fig.update_yaxes(range=<VALUE>)
Type: list

https://plotly.com/python/reference/layout/yaxis/#layout-xaxis-range

关于标签/标题：

Code: fig.update_yaxes(title=dict(...))
Type: dict containing one or more of the keys listed below.

fig.update_layout(title_text=<VALUE>)

https://plotly.com/python/reference/layout/yaxis/#layout-yaxis-title

- astrochun

---

我知道这个，我也读了文档。但我无法弄清如何更改一个 y 轴（我有两个）。 - Mathijs van den Doel

你试过使用 secondary_y = False 或 True 吗？详情请见：https://plotly.com/python/multiple-axes/ - astrochun

fig contains both axes, so when updating, you still need to be explicit. Much like how you use add_trace, you need to specify secondary_y in your fig.update_yaxes - astrochun

谢谢，就这些。 - Mathijs van den Doel

@MathijsvandenDoel，等我有机会的时候，我会修改我的答案，使其成为一个可接受的答案。 - astrochun