Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

diverging.domain([x0, x1][, pivot]) sets the domain from a 2-element extent & pivot #215

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -629,9 +629,11 @@ If *interpolator* is an array, it represents the scale’s three-element output

See [*continuous*](#_continuous).

<a name="diverging_domain" href="#diverging_domain">#</a> <i>diverging</i>.<b>domain</b>([<i>domain</i>]) · [Source](https://github.com/d3/d3-scale/blob/master/src/diverging.js), [Examples](https://observablehq.com/@d3/diverging-scales)
<a name="diverging_domain" href="#diverging_domain">#</a> <i>diverging</i>.<b>domain</b>([<i>domain</i>][, <i>pivot</i>]) · [Source](https://github.com/d3/d3-scale/blob/master/src/diverging.js), [Examples](https://observablehq.com/@d3/diverging-scales)

See [*continuous*.domain](#continuous_domain). Note that a diverging scale’s domain must be numeric and must contain exactly three values. The default domain is [0, 0.5, 1].
If *domain* is specified with three values [x0, pivot, x1], sets the scale’s domain to the specified array. If *domain* contains two elements [x0, x1], inserts the (optional) *pivot* in-between, and updates [x0, x1] to bracket the pivot. Usually [x0, x1] is the extent of the values, in ascending or descending order.

The default domain is [0, 0.5, 1].

<a name="diverging_clamp" href="#diverging_clamp">#</a> <i>diverging</i>.<b>clamp</b>([<i>clamp</i>]) · [Source](https://github.com/d3/d3-scale/blob/master/src/diverging.js), [Examples](https://observablehq.com/@d3/diverging-scales)

Expand Down
14 changes: 12 additions & 2 deletions src/diverging.js
Original file line number Diff line number Diff line change
Expand Up @@ -26,8 +26,18 @@ function transformer() {
return isNaN(x = +x) ? unknown : (x = 0.5 + ((x = +transform(x)) - t1) * (s * x < s * t1 ? k10 : k21), interpolator(clamp ? Math.max(0, Math.min(1, x)) : x));
}

scale.domain = function(_) {
return arguments.length ? ([x0, x1, x2] = _, t0 = transform(x0 = +x0), t1 = transform(x1 = +x1), t2 = transform(x2 = +x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), s = t1 < t0 ? -1 : 1, scale) : [x0, x1, x2];
function domainExtent(extent, pivot) {
extent = Array.from(extent);
if (extent.length >= 3) return extent;
const [x0, x1] = extent;
pivot = +pivot || 0;
return x1 > x0
? [Math.min(pivot, x0), pivot, Math.max(pivot, x1)]
: [Math.max(pivot, x0), pivot, Math.min(pivot, x1)];
}

scale.domain = function(_, __) {
return arguments.length ? ([x0, x1, x2] = domainExtent(_, __), t0 = transform(x0 = +x0), t1 = transform(x1 = +x1), t2 = transform(x2 = +x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), s = t1 < t0 ? -1 : 1, scale) : [x0, x1, x2];
};

scale.clamp = function(_) {
Expand Down
21 changes: 21 additions & 0 deletions test/diverging-test.js
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,27 @@ tape("diverging.domain() handles a degenerate domain", function(test) {
test.end();
});

tape("diverging.domain() handles a two-values domain with a pivot", function(test) {
var s = scale.scaleDiverging().domain([2, 3]);
test.deepEqual(s.domain(), [0, 0, 3]);
s.domain([-2, -1]);
test.deepEqual(s.domain(), [-2, 0, 0]);
s.domain([-5, 1256], 100);
test.deepEqual(s.domain(), [-5, 100, 1256]);
test.end();
});

tape("diverging.domain() handles a two-values descending domain", function(test) {
var s = scale.scaleDiverging();
s.domain([2, -2]);
test.deepEqual(s.domain(), [2, 0, -2]);
s.domain([2, -2], 1);
test.deepEqual(s.domain(), [2, 1, -2]);
s.domain([2, -2], -3);
test.deepEqual(s.domain(), [2, -3, -3]);
test.end();
});

tape("diverging.domain() handles a descending domain", function(test) {
var s = scale.scaleDiverging().domain([4, 2, 1]);
test.deepEqual(s.domain(), [4, 2, 1]);
Expand Down