Symlog scales¶

detroit.scale_symlog() → ScaleSymlog¶

detroit.scale_symlog(range_vals: list[T]) → ScaleSymlog

detroit.scale_symlog(domain: list[int | float], range_vals: list[T]) → ScaleSymlog

Builds a new continuous scale with the specified domain and range, the constant 1, the default interpolator and clamping disabled.

Parameters:

domain (list[Number]) – Array of numbers
range_vals (list[Number]) – Array of values

Returns:

Scale object

Return type:

ScaleSymlog

Examples

>>> scale = d3.scale_symlog([0, 100], [0, 960])
>>> scale = scale.set_constant(2)
>>> steps = 10
>>> scale(0)
0.0
>>> scale(0.5)
54.48303899306232
>>> for x in range(steps + 1):
...     x = 2 * x / steps
...     x = 10 ** x
...     print(x, scale(x))
...
...
1.0 98.9989231832065
1.5848931924611136 142.48806851481947
2.51188643150958 198.64193111140278
3.9810717055349722 267.46722288814453
6.309573444801933 347.7495648320975
10.0 437.47847720986016
15.848931924611133 534.4195868305859
25.118864315095795 636.548856160817
39.810717055349734 742.2519630838442
63.09573444801933 850.343754278314

class detroit.scale.symlog.ScaleSymlog(c: int | float = 1)¶

A bi-symmetric log transformation for wide-range data by Webber for details. Unlike a log scale, a symlog scale domain can include zero.

Parameters:: c (Number) – Symlog constant value

__call__(x: int | float | datetime) → T¶

Given a value from the domain, returns the corresponding value from the range.

Parameters:: x (int | float) – Input value
Returns:: Corresponding value from the range
Return type:: T

invert(y: T) → int | float¶

Given a value from the range, returns the corresponding value from the domain. Inversion is useful for interaction, say to determine the data value corresponding to the position of the mouse.

Parameters:: y (T) – Input value
Returns:: Corresponding value from the domain
Return type:: Number

set_domain(domain)¶

Sets the scale’s domain to the specified array of numbers.

Parameters:: domain (list[Number] | list[datetime]) – Domain
Returns:: Itself
Return type:: Transformer[T]

set_range(range_vals)¶

Sets the scale’s range to the specified array of values

Parameters:: range_vals (list[T]) – Range values
Returns:: Itself
Return type:: Transformer[T]

set_range_round(range_vals: list[T]) → Transformer¶

Sets the scale’s range to the specified array of values and sets scale’s interpolator to interpolate_round.

Parameters:: range_vals (list[T]) – Range values
Returns:: Itself
Return type:: Transformer

set_constant(c: int | float) → ScaleSymlog¶

Sets the symlog constant to the specified number and returns this scale.

Parameters:: c (Number) – Constant value
Returns:: Itself
Return type:: ScaleSymlog

set_clamp(clamp: bool) → Transformer¶

Enables or disables clamping.

Parameters:: clamp (bool) – Clamp value
Returns:: Itself
Return type:: Transformer

set_interpolate(interpolate: Callable[[T, T], Callable[[float], T]]) → Transformer[T]¶

Sets the scale’s range interpolator factory.

Parameters:: interpolate (Callable[[T, T], Callable[[float], T]]) – Interpolate function
Returns:: Itself
Return type:: Transformer[T]

set_unknown(unknown: Any) → Transformer¶

Sets the output value of the scale for undefined or NaN input values.

Parameters:: unknown (Any) – Unknown value
Returns:: Itself
Return type:: Transformer

ticks(count: int | None = None) → list[int | float]¶

Returns approximately count representative values from the scale’s domain.

Parameters:: count (int | None) – Count. If specified, the scale may return more or fewer values depending on the domain
Returns:: Tick values are uniformly spaced, have human-readable values (such as multiples of powers of 10), and are guaranteed to be within the extent of the domain. Ticks are often used to display reference lines, or tick marks, in conjunction with the visualized data.
Return type:: list[Number]

tick_format(count: int | None = None, specifier: str | None = None) → Callable[[int | float], str]¶

Returns a number format function suitable for displaying a tick value, automatically computing the appropriate precision based on the fixed interval between tick values. The specified count should have the same value as the count that is used to generate the tick values.

Parameters:

count (int | None) – Count. It should have the same value as the count that is used to generate the tick values.
specifier (str | None) – Specifier

Returns:

Tick format function

Return type:

Callable[[Number], str]

nice(count: int | None = None) → LinearBase¶

Extends the domain so that it starts and ends on nice round values.

Parameters:: count (int | None) – Count argument allows greater control over the step size used to extend the bounds, guaranteeing that the returned ticks will exactly cover the domain
Returns:: Itself
Return type:: LinearBase