This example use a custom path interpolator, as opposed to the other examples.
The interpolator interpolates the number of elements of the array and inserts missing elements
<!DOCTYPE html> | |
<meta charset="utf-8"> | |
<style> | |
.frame { | |
fill: none; | |
stroke: #000; | |
} | |
.axis text { | |
font: 10px sans-serif; | |
} | |
.axis line, | |
.axis circle { | |
fill: none; | |
stroke: #777; | |
stroke-dasharray: 1,4; | |
} | |
.axis :last-of-type circle { | |
stroke: #333; | |
stroke-dasharray: none; | |
} | |
.line { | |
fill: none; | |
stroke: red; | |
stroke-width: 1.5px; | |
} | |
</style> | |
<body> | |
<script src="http://d3js.org/d3.v3.min.js"></script> | |
<script> | |
d3.interpolators.push(function(a,b){ | |
if (Array.isArray(a[0]) && Array.isArray(b[0])) { | |
var x = [], | |
c = [], | |
na = a.length, | |
nb = b.length, | |
n0 = Math.min(a.length, b.length), | |
i, | |
delta = b.length - a.length, | |
newSize; | |
console.log('No',na,nb); | |
for (i=0; i < na; ++i) | |
{ | |
c[i]=b[i]; | |
} | |
newSize; | |
return function(t) { | |
newSize = a.length + delta*t; | |
//console.log(newSize,c.length,t,delta); | |
if (newSize>c.length){ | |
for (i=c.length;i<newSize;i++) c.push(b[i]); | |
} | |
return c; | |
} | |
} | |
}); | |
function d3_interpolateArray(a, b) { | |
//we suppose a is smaller | |
var x = [], | |
c = [], | |
na = a.length, | |
nb = b.length, | |
n0 = Math.min(a.length, b.length), | |
i, | |
delta = b.length - a.length, | |
newSize; | |
for (i = 0; i < n0; ++i) x.push(d3_interpolate([0,0], b[i])); | |
for (i=0; i < na; ++i) c[i] = a[i]; | |
return function(t) { | |
newSize = a.length + delta*t; | |
if (newSize>c.length) c.push(b[newSize]); | |
for (i = 0; i < c.length; ++i) c[i] = x[i](t); | |
return c; | |
}; | |
} | |
var data = d3.range(0, 2*Math.PI, .01).map(function(t) { | |
return [t, Math.sin(4*t)]; | |
}); | |
var empty = d3.range(0, 2*Math.PI, .01).map(function(t) { | |
return [0,0]; | |
}); | |
var margin = 30; | |
// radius is the minimal dimension, minus the margin | |
var width = 960, | |
height = 500, | |
radius = Math.min(width, height) / 2 - margin; | |
var r = d3.scale.linear() | |
.domain([0, 1]) | |
.range([0, radius]); | |
//default accessor [[x1,y1]] => radian and angle | |
var line = d3.svg.line.radial() | |
.radius(function(d){; return (r(d[1])); }) // will change between -1 and 1 | |
.angle(function(d) { ;return d[0];}); | |
var svg = d3.select("body").append("svg") | |
.attr("width", width) | |
.attr("height", height) | |
.append("g") | |
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")"); | |
// radius axis | |
// cheat with CSS | |
var gr = svg.append("g") | |
.attr("class", "r axis") | |
.selectAll("g") | |
.data(r.ticks(10).slice(0)) | |
.enter().append("g"); | |
gr.append("circle") | |
.attr("r", function(d,i){console.log("=>",d,i,r(d));return r(d)}); | |
gr.append("text") | |
.attr("y", function(d) { return -r(d) - 4; }) | |
.attr("transform", "rotate(50)") | |
.style("text-anchor", "middle") | |
.text(function(d) { return d; }); | |
var ga = svg.append("g") | |
.attr("class", "a axis") | |
.selectAll("g") | |
.data(d3.range(0, 360, 15)) | |
.enter().append("g") | |
.attr("transform", function(d) { return "rotate(" + (d-90) + ")"; }); | |
ga.append("line") | |
.attr("x2", radius); | |
ga.append("text") | |
.attr("x", radius + 6) | |
.attr("dy", ".35em") | |
.style("text-anchor", function(d) { return d < 270 && d > 90 ? "end" : null; }) | |
.attr("transform", function(d) { return d < 270 && d > 90 ? "rotate(180 " + (radius + 6) + ",0)" : null; }) | |
.text(function(d) { return d + "°"; }); | |
// a bit cheating | |
var path = | |
svg.append("path") | |
.datum(data) | |
.attr("class", "line") | |
.attr("d", line); | |
var totalLength = path.node().getTotalLength(); | |
path.transition().duration(1000).attrTween("d",function(d){ | |
console.log(empty,d); | |
var interpolate = d3.interpolate( [[0,0]],d); | |
return function(t) { return line(interpolate(t))}; | |
}) | |
</script> | |
</body> | |