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@enjalot
Last active August 29, 2015 14:22
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sampling
{"description":"sampling","endpoint":"","display":"svg","public":true,"require":[],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"pingpong","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"ajax-caching":true,"thumbnail":"http://i.imgur.com/RA6u5UJ.png"}
var height = 150;
var points = [
{x: 100, y: 100},
{x: 150, y: 114},
{x: 200, y: 75},
{x: 250, y: 90}
]
var line = d3.svg.line()
.x(function(d) {
return d.x
})
.y(function(d) {
return d.y
})
.interpolate("cardinal")
//.interpolate("basis")
var svg = d3.select("svg")
var path = svg.append("path")
.attr("d", line(points))
.style({
fill: "none",
stroke: "#000",
"stroke-width": 3
})
var circles = svg.selectAll("circle")
.data(points)
.enter().append("circle")
.attr({
cx: function(d) { return d.x },
cy: function(d) { return d.y },
r: 5,
fill: "none",
stroke: "#6d6d6d"
})
var node = path.node()
var samples = getSamples(node, 49);
var rects = svg.selectAll("rect")
.data(samples)
.enter().append("rect")
.attr({
x: function(d) { return d.x },
y: function(d) { return d.y },
width: 1,
height: function(d) { return height - d.y }
})
function getSamples(path, num) {
var len = path.getTotalLength()
var p;
var result = []
for(var i = 0; i < num; i++) {
p = path.getPointAtLength(i * len/num);
result.push(p);
}
return result
}
function getArea(samples, x) {
// TODO faster search
var total = 0;
var s;
for(var i = 0; i < samples.length; i++) {
s = samples[i];
if(s.x > x) break;
total += s.y;
}
return total;
}
console.log("area", getArea(samples, 195));
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