Scatter Plot

scatter_plot.js

$(document).ready(function() {

  var margin = {top: 20, right: 20, bottom: 160, left: 40},
      width = $("#scatter-plot").width() - margin.left - margin.right,
      height = 600 - margin.top - margin.bottom;

  // setup x 
  var xValue = function(d) { return d.acres;}, // data -> value
      xScale = d3.scale.linear().range([0, width]), // value -> display
      xMap = function(d) { return xScale(xValue(d));}, // data -> display
      xAxis = d3.svg.axis().scale(xScale).orient("bottom");

  // setup y
  var yValue = function(d) { return d.vertical;}, // data -> value
      yScale = d3.scale.linear().range([height, 0]), // value -> display
      yMap = function(d) { return yScale(yValue(d));}, // data -> display
      yAxis = d3.svg.axis().scale(yScale).orient("left");

  // setup fill color
  var cValue = function(d) { return d.state;},
      color = d3.scale.category20();

  // add the graph canvas to the #scatter-plot of the webpage
  var svg = d3.select("#scatter-plot").append("svg")
      .attr("width", width + margin.left + margin.right)
      .attr("height", height + margin.top + margin.bottom)
    .append("g")
      .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

  var stateColor = "state";
  var colorScale = d3.scale.category20c ();

  // add the tooltip area to the webpage
  var tooltip = d3.select("body").append("div") 
    .attr("class", "tooltip")       
    .style("opacity", 0);


  var acreageThreshold = 1000  ; //not greater than 4000

  // load data
  d3.csv("/ski_resort_acres_three.csv", function(error, data) {

    data = jQuery.grep(data, function(d, index) {
      var is_viewable = d.acres <= acreageThreshold;
      return is_viewable;
    });

    // change string (from CSV) into number format
    data.forEach(function(d) {
      d.acres = +d.acres;
      d.vertical = +d.vertical;
    });

    // don't want dots overlapping axis, so add in buffer to data domain
    xScale.domain([d3.min(data, xValue)-1, d3.max(data, xValue)+1]);
    yScale.domain([d3.min(data, yValue)-1, d3.max(data, yValue)+1]);

    // x-axis
    svg.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + height + ")")
        .call(xAxis)
      .append("text")
        .attr("class", "label")
        .attr("x", width)
        .attr("y", -6)
        .style("text-anchor", "end")
        .text("Acres");

    // y-axis
    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis)
      .append("text")
        .attr("class", "label")
        .attr("transform", "rotate(-90)")
        .attr("y", 6)
        .attr("dy", ".71em")
        .style("text-anchor", "end")
        .text("Vertical Drop");

    // draw dots
    svg.selectAll(".dot")
        .data(data)
      .enter().append("circle")
        .attr("class", "dot")
        .attr("r", function(d) { return Math.sqrt(d.acres)/5; })
        .attr("cx", xMap)
        .attr("cy", yMap)
        .style("fill", function(d) { return color(cValue(d));})
        .style("opacity", .6)
        .style("stroke-opacity", .3) 
        .on("mouseover", function(d) {
          circle = d3.select(this)
          tooltip.transition()    
            .duration(20)    
            .style("opacity", 1)
          circle.transition()    
            .duration(100)    
            .style("opacity", 1)
            .style("stroke-opacity", 1)   
          tooltip.html(d.resort_name + "<br/>"  + addCommas(d.acres) + " ac /   " + addCommas(d.vertical) + " ft")  
            .style("left", (d3.event.pageX) + "px")   
            .style("top", (d3.event.pageY-28) + "px");  
        })          
        .on("mouseout", function(d) {   
          tooltip.transition()    
            .duration(500)    
            .style("opacity", 0) 
          circle.transition()    
            .duration(200)    
            .style("opacity", .6)
            .style("stroke-opacity", .3) 
        });
  });
});