Brush scatterplot, three by one matrix

Adapted from /mbostock/4063663, this only chooses certain combinations of dimensions to display in a 3x1 matrix

<!DOCTYPE html>
<meta charset="utf-8">
<title>Trees</title>
<style>

svg {
  font: 10px sans-serif;
  padding: 10px;
}

.axis,
.frame {
  shape-rendering: crispEdges;
}

.axis line {
  stroke: #ddd;
}

.axis path {
  display: none;
}

.frame {
  fill: none;
  stroke: #aaa;
}

.field {
  fill: lightgreen;
  stroke: #aaa;
  fill-opacity: .5;
}

circle {
  fill-opacity: .7;
}

circle.hidden {
  fill: #ccc !important;
}

.extent {
  fill: #000;
  fill-opacity: .125;
  stroke: #fff;
}

.chartTitles {
	font-size: 20px;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>

var width = 1400,
    size = 400,
    padding = 40,
	gap = 30,
	noOfCharts = 3;

var x = d3.scale.linear()
    .range([padding / 2, size - padding / 2]);

var y = d3.scale.linear()
    .range([size - padding / 2, padding / 2]);

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom")
    .ticks(5);

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .ticks(5);

var color = d3.scale.category10();

d3.csv("trees2.csv", function(error, data) {

var chartTitles = [	"Annual growth by distance from spring",
						"Map of the woods",
						"Height by age of tree" ];

data.forEach(function(d) { 
		d.lng = +d.lng; 
		d.lat = +d.lat; 
		d.distanceNW = +d.distanceNW; 
		d.height = +d.height; 
		d.distanceSpring = +d.distanceSpring; 
		d.growth = +d.growth; 
		d.age = +d.age;
		
	});

var domainByTrait = {},
      traits = d3.keys(data[0]).filter(function(d) { return d !== "tree"; }),
      n = traits.length;

//console.log(traits);
	  
  traits.forEach(function(trait) {
    domainByTrait[trait] = d3.extent(data, function(d) { return d[trait]; });
  });
  
  //console.log(domainByTrait["distanceNW"]);

xAxis.tickSize(size - padding);
  yAxis.tickSize(-size + padding);

var brush = d3.svg.brush()
      .x(x)
      .y(y)
      .on("brushstart", brushstart)
      .on("brush", brushmove)
      .on("brushend", brushend);

var svg = d3.select("body").append("svg")
      .attr("width", size * noOfCharts + padding)
      .attr("height", size + padding)
    .append("g")
      .attr("transform", "translate(" + padding + "," + padding / 2 + ")");

svg.selectAll(".x.axis")
      .data(["age", "lng", "distanceSpring"])
    .enter().append("g")
      .attr("class", "x axis")
      .attr("transform", function(d, i) { return "translate(" + (((3 - i - 1) * size)  ) + "," + (padding/2) +")"; })
      .each(function(d) { x.domain(domainByTrait[d]); d3.select(this).call(xAxis); });

svg.selectAll(".y.axis")
      .data(["growth", "lat", "height"])
    .enter().append("g")
      .attr("class", "y axis")
      .attr("transform", function(d, i) { return "translate(" + (i * size + (padding/2)) + ", 0)"; })
      .each(function(d) { y.domain(domainByTrait[d]); d3.select(this).call(yAxis); });

var  cells = [{x: "age", y: "height", i: 0, j: 0},
		 {x: "lng", y: "lat", i: 1, j: 0} ,
		 {x: "distanceSpring", y: "growth", i: 2, j: 0}];

var cell = svg.selectAll(".cell")
      .data(cells)
    .enter().append("g")
      .attr("class", "cell")
      .attr("transform", function(d) { return "translate(" + (noOfCharts - d.i - 1) * size + "," + d.j * size + ")"; })
      .each(plot);

cell.call(brush);
  
  
  var titles = svg.selectAll(".chartTitles")
	.data(chartTitles)
	.enter()
	.append("text")
	.attr("class", "chartTitles")
	.attr("text-anchor", "middle")
	.attr("transform", function(d, i) { return "translate(" + ((i * size) + (size/2) ) + ", 5)" ;  })
	.text(function(d) {return d; });

function plot(p) {
    var cell = d3.select(this);

x.domain(domainByTrait[p.x]);
    y.domain(domainByTrait[p.y]);

cell.append("rect")
        .attr("class", function (d) {
				var classname = "frame";
				if (d.i === 1) {classname = "field";} ;
				return classname;
			}) 
        .attr("x", padding / 2)
        .attr("y", padding / 2)
        .attr("width", size - padding)
        .attr("height", size - padding);
	
    cell.selectAll("circle")
        .data(data)
      .enter().append("circle")
        .attr("cx", function(d) { return x(d[p.x]); })
        .attr("cy", function(d) { return y(d[p.y]); })
        .attr("r", 5)
        .style("fill", "darkgreen" /*function(d) { return color(d.species); }*/);
  }

var brushCell;

// Clear the previously-active brush, if any.
  function brushstart(p) {
    if (brushCell !== this) {
      d3.select(brushCell).call(brush.clear());
      x.domain(domainByTrait[p.x]);
      y.domain(domainByTrait[p.y]);
      brushCell = this;
    }
  }

// Highlight the selected circles.
  function brushmove(p) {
    var e = brush.extent();
    svg.selectAll("circle").classed("hidden", function(d) {
      return e[0][0] > d[p.x] || d[p.x] > e[1][0]
          || e[0][1] > d[p.y] || d[p.y] > e[1][1];
    });
  }

// If the brush is empty, select all circles.
  function brushend() {
    if (brush.empty()) svg.selectAll(".hidden").classed("hidden", false);
  }

/*
  function cross(a, b) {
    var c = [], n = a.length, m = b.length, i, j;
    //for (i = -1; ++i < n;) for (j = -1; ++j < m;) c.push({x: a[i], i: i, y: b[j], j: j});
    c = [{x: "distanceNW", y: "height", i: 0, j: 0},
		 {x: "lng", y: "lat", i: 1, j: 0} ,
		 {x: "distanceSpring", y: "growth", i: 2, j: 0}];
	console.log(c);
	return c;
  }
*/
  d3.select(self.frameElement).style("height", size * n + padding + 20 + "px");
});

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js