simple horizon++

_.md

[ Launch: simple horizon++ ] de713c5d78463d41e09c by enjalot

config.json

{"description":"simple horizon++","endpoint":"","display":"svg","public":true,"require":[],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"horizon.js":{"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}

horizon.js

(function() {
  d3.horizon = function() {
    var bands = 1, // between 1 and 5, typically
        mode = "offset", // or mirror
        interpolate = "linear", // or basis, monotone, step-before, etc.
        x = d3_horizonX,
        y = d3_horizonY,
        width = 960,
        height = 40;

    var color = d3.scale.linear()
        .domain([-1, 0, 1])
        .range(["#d62728", "#fff", "#1f77b4"]);

    // For each small multiple…
    function horizon(g) {
      g.each(function(d) {
        var g = d3.select(this),
            xMin = Infinity,
            xMax = -Infinity,
            yMax = -Infinity,
            x0, // old x-scale
            y0, // old y-scale
            t0,
            id; // unique id for paths

        // Compute x- and y-values along with extents.
        var data = d.map(function(d, i) {
          var xv = x.call(this, d, i),
              yv = y.call(this, d, i);
          if (xv < xMin) xMin = xv;
          if (xv > xMax) xMax = xv;
          if (-yv > yMax) yMax = -yv;
          if (yv > yMax) yMax = yv;
          return [xv, yv];
        });

        // Compute the new x- and y-scales, and transform.
        var x1 = d3.scale.linear().domain([xMin, xMax]).range([0, width]),
            y1 = d3.scale.linear().domain([0, yMax]).range([0, height * bands]),
            t1 = d3_horizonTransform(bands, height, mode);

        // Retrieve the old scales, if this is an update.
        if (this.__chart__) {
          x0 = this.__chart__.x;
          y0 = this.__chart__.y;
          t0 = this.__chart__.t;
          id = this.__chart__.id;
        } else {
          x0 = x1.copy();
          y0 = y1.copy();
          t0 = t1;
          id = ++d3_horizonId;
        }

        // We'll use a defs to store the area path and the clip path.
        var defs = g.selectAll("defs")
            .data([null]);

        // The clip path is a simple rect.
        defs.enter().append("defs").append("clipPath")
            .attr("id", "d3_horizon_clip" + id)
          .append("rect")
            .attr("width", width)
            .attr("height", height);

        d3.transition(defs.select("rect"))
            .attr("width", width)
            .attr("height", height);

        // We'll use a container to clip all horizon layers at once.
        g.selectAll("g")
            .data([null])
          .enter().append("g")
            .attr("clip-path", "url(#d3_horizon_clip" + id + ")");

        // Instantiate each copy of the path with different transforms.
        var path = g.select("g").selectAll("path")
            .data(d3.range(-1, -bands - 1, -1).concat(d3.range(1, bands + 1)), Number);

        var d0 = d3_horizonArea
            .interpolate(interpolate)
            .x(function(d) { return x0(d[0]); })
            .y0(height * bands)
            .y1(function(d) { return height * bands - y0(d[1]); })
            (data);

        var d1 = d3_horizonArea
            .x(function(d) { return x1(d[0]); })
            .y1(function(d) { return height * bands - y1(d[1]); })
            (data);

        path.enter().append("path")
            .style("fill", color)
            .attr("transform", t0)
            .attr("d", d0);

        d3.transition(path)
            .style("fill", color)
            .attr("transform", t1)
            .attr("d", d1);

        d3.transition(path.exit())
            .attr("transform", t1)
            .attr("d", d1)
            .remove();

        // Stash the new scales.
        this.__chart__ = {x: x1, y: y1, t: t1, id: id};
      });
    }

    horizon.bands = function(_) {
      if (!arguments.length) return bands;
      bands = +_;
      color.domain([-bands, 0, bands]);
      return horizon;
    };

    horizon.mode = function(_) {
      if (!arguments.length) return mode;
      mode = _ + "";
      return horizon;
    };

    horizon.colors = function(_) {
      if (!arguments.length) return color.range();
      color.range(_);
      return horizon;
    };

    horizon.interpolate = function(_) {
      if (!arguments.length) return interpolate;
      interpolate = _ + "";
      return horizon;
    };

    horizon.x = function(_) {
      if (!arguments.length) return x;
      x = _;
      return horizon;
    };

    horizon.y = function(_) {
      if (!arguments.length) return y;
      y = _;
      return horizon;
    };

    horizon.width = function(_) {
      if (!arguments.length) return width;
      width = +_;
      return horizon;
    };

    horizon.height = function(_) {
      if (!arguments.length) return height;
      height = +_;
      return horizon;
    };
    
    horizon.colors = function(_) {
      if (!arguments.length) return color.range();
      color.range(_);
      return horizon;
    };

    return horizon;
  };

  var d3_horizonArea = d3.svg.area(),
      d3_horizonId = 0;

  function d3_horizonX(d) { return d[0]; }
  function d3_horizonY(d) { return d[1]; }

  function d3_horizonTransform(bands, h, mode) {
    return mode == "offset"
        ? function(d) { return "translate(0," + (d + (d < 0) - bands) * h + ")"; }
        : function(d) { return (d < 0 ? "scale(1,-1)" : "") + "translate(0," + (d - bands) * h + ")"; };
  }
})();

inlet.js

// change the second number to affect the values.
// the first number is used for the x-axis, it should be numbers in order
// play with j to see what happens when you skip x values
var j = 0
var data = [
  [3,2],
  [4,3],
  [5,4],
  [6, 10], 
  [7,20],
  [8,33],
  [9,5],
  [10+j,6],
  [11+j,7],
  [12+j,14],
  [13+j,12],
  [14+j,22],
  [15+j,13],
  [16+j,14]
];


var colors = ["#d727a5", "#ffffff", "#1eb268"];
var width = 400;
var height = 200;

var svg = d3.select("svg");
var chart = d3.horizon()
    .width(width)
    .height(height)
    .bands(8)
    .height(height)
    .mode("mirror")
    .interpolate("step-after")
    //.colors(colors);

var g = svg.append("g")
.attr("transform", "translate(" + [ 51, 50 ] +")")
g.append("rect")
.attr({
  x: -1,
  y: -1,
  width: width + 2,
  height: height + 2
})
g.datum(data);
chart(g);