Dynamic min, max and step for binding_range?

[romanzes637]

This task is derived from #1617.
What If we have dynamic axes with different ranges and want to filter them by slider (binding_range)?

For example:

import pandas as pd
import altair as alt
import numpy as np

# x, y - 2D vector components
# c1, c2, c3, c4, c5, c6 - 6D vector components
# field - some scalar field
df = pd.DataFrame({
  'x': [1.574978, 1.795649, 1.725641, 0.02946, 1.957083, 
        0.24196, 0.258188, 0.5444, 0.841816, -1.17396], 
  'y': [1.033189, 1.210541, 0.879006, 1.123178, 0.616626, 
        0.43055, 0.837882, 0.568572, 0.397429, -1.938288],
  'c1': [-0., -0., -0., 0., -0., -0., 0., 0., 0., 0.],
  'c2': [-0.2, -0.3, -0.2, -0.3, -0.3, -0.3, -0.3, -0.4, -0.4, -0.4],
  'c3': [1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
  'c4': [-0., -0., -0., -0., 0., -0., -0., 0., 0., 0.],
  'c5': [0.3, 0.3, 0.4, 0.4, 0.4, 0.5, 0.5, 0.5, 0.6, 0.7],
  'c6': [-0.1, -0.1, -0.1, -0.1, -0.2, -0.2, -0.1, -0.2, -0.2, -0.3],
  'field': [100, 1000, 500, 600, -300, -200, -100, 300, 500, 0]
  })

columns = ['c1', 'c2', 'c3', 'c4', 'c5', 'c6', 'field']
select_box = alt.binding_select(options=columns, name='column')
sel = alt.selection_single(fields=['column'], bind=select_box, 
                           init={'column': 'c5'}, 
                           clear=False, on='none')

slider = alt.binding_range(min=-1e0, max=1e0, step=1e-2)
threshold = alt.selection_single(name="threshold", fields=['value_t'],
                                 bind=slider, init={'value_t': 0})

chart = alt.Chart(df.reset_index()).transform_fold(
    columns,
    as_=['column', 'value']
).transform_filter(
    sel
).mark_point().encode(
    x='x:Q',
    y='y:Q',
    color=alt.condition('datum.value > threshold_value_t', 
                        'value:Q', alt.value('red')),
    tooltip=['index', 'x', 'y'] + columns
).add_selection(
    sel,
    threshold
)

If the value is in the slider range that's ok.

But if not, we can't filter it...
We could of course expand the range of the slider, but then we don’t have enough resolution for small values, respectively...

Interactive example: https://romanzes637.github.io/