Is it possible to scale yrange automatically in holoviews?

Question

I used holoviews to display the line chart, but when I move it horizontally with the pan tool, the line goes off the screen in the vertical direction. Therefore, I wanted a function that autoscales yrange so that the line does not jump out of the screen at any time.

My ideal is the graph on this site. https://www.binance.com/en/trade/BTC_USDT

Is there a way to implement this using holoviews?

Answer 1

With reference to the official tutorial, I implemented a simple code for autoscale.

HoloViews user guide -「Custom Interactivity」

The autoscale() works only for Holoviews' drawing methods that take X, Y as arguments, such as hv.Scatter, hv.Curve, hv.Point, hv.Histogram, hv.Area.

import numpy as np
import pandas as pd
import holoviews as hv
hv.extension("bokeh")

def autoscale(fig):
    x, y  = fig.dimension_values(0), fig.dimension_values(1)
    def draw(x_range, y_range):
        if not x_range: return fig
        xr_start, xr_end = x_range
        mask = (xr_start < x) & (x < xr_end)
        yr_start, yr_end = y[mask].min(), y[mask].max()
        yr_start, yr_end = yr_start - (abs(yr_end - yr_start)*0.1), yr_end + (abs(yr_end - yr_start)*0.1)
        if yr_start == False or yr_start == None or yr_start == yr_end:
            yr_start, yr_end = y_range
        return fig.opts(hooks=[
            lambda plot, _:
                plot.handles['y_range'].update(start=yr_start, end=yr_end)
        ], active_tools=["wheel_zoom"])
    return hv.DynamicMap(draw, streams=[hv.streams.RangeXY()])

x = pd.date_range("2020-01-01", "2020-4-09")
y = np.cumsum(np.random.randn(len(x)))

autoscale(hv.Curve((x, y)) * hv.Curve((x, y*1.5))) # also works overlay
autoscale(hv.Curve((x, y)))

It looks like we can improve it, but I hope the official will provide an autoscale feature.