Published
Edited
Nov 22, 2019
1 star
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draw(interpolateRound(0, 2)) // unbalanced 😱
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draw(interpolateBalanced(0, 2)) // balanced 😇
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interpolateBalanced(0, 2)(0.7)
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interpolateRound(0, 2)(0.7)
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interpolateRound = (a, b) => {
// d3.interpolateRound
return function(t) {
return Math.round(a * (1 - t) + b * t);
};
}
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interpolateBalanced = (a, b) => {
// epsilon is needed to have an exact value for t=1
var div = Math.abs(b - a) + epsilon;
return function(t) {
t += (t - 1 / 2) / div;
return Math.round(a * (1 - t) + b * t);
};
}
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interpolateBalanced2 = (a, b) => {
// suggested by @jrus
// epsilon is needed to have an exact value for t=1
var sign = Math.sign(b - a);
return interpolateRound(
a - sign * (0.5 - epsilon),
b + sign * (0.5 - epsilon)
);
}
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draw(interpolateBalanced(0, -2))
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draw(interpolateBalanced(0, 0))
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draw(interpolateRound(0, 7))
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draw(interpolateBalanced(0, 7))
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draw(interpolateBalanced2(0, 7))
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draw(interpolateBalanced(7, 0))
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draw(interpolateBalanced2(7, 0))
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draw(interpolateBalanced(0.1, 2.5))
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function draw(interpolate) {
const context = DOM.context2d(width, 30);

for(let i=0; i < width; i++) {
context.fillStyle = color(interpolate(i/(width-1)))
context.fillRect(i,0,2,30);
}
return context.canvas
}
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color = d3.scaleOrdinal(d3.schemeCategory10)
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d3 = require("d3@5")
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import { epsilon } from "@fil/math"
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