D3缩放行为

Question

i'm trying to use Zoom behavior for my scatter plot graph. I have research around online and this is the most simple method that i could implement for my graph. But i am having some problems with my codes. It's only when i added

var zoom = d3.behavior.zoom()
     .scaleExtent([1, 10])
     .on("zoom", zoomed); #this line

Then my whole graph will just disappear Any reasons why? I am very very new to d3... thanks for help in advance! :)

var margin = {top: 30, right: 20, bottom: 30, left: 50},    
     width = 1100 - margin.left - margin.right,             
     height = 600 - margin.top - margin.bottom;             

var zoom = d3.behavior.zoom()
     .scaleExtent([1, 10])
     .on("zoom", zoomed); #This line

var parseDate = d3.time.format("%Y-%m-%dT%H:%M:%S").parse;  


var x = d3.time.scale().range([0, width]);  
var y = d3.scale.linear().range([height, 0]);           



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




var valueline = d3.svg.line()                               
     .x(function(d) { return x(d.startDateTime); })             
     .y(function(d) { return y(d.Ranking); });                  



 var svg = d3.select(".graph")
     .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 + ")");



 function make_y_axis() {
     return d3.svg.axis()
         .scale(y)
         .orient("left")
         .ticks(4)
 }

function make_x_axis() {
     return d3.svg.axis()
     .scale(x)
     .orient("bottom")
     .ticks(4)
 }




d3.csv("FinalCSVFile.csv", function(error, data) {          
    data.forEach(function(d) {                              
    d.startDateTime = parseDate(d.startDateTime);                           
    d.Ranking = +d.Ranking;                                 
});


// Scale the range of the data
x.domain(d3.extent(data, function(d) { return d.startDateTime; }));     
y.domain([0, d3.max(data, function(d) { return d.Ranking; })]); 



// Add the X Axis
svg.append("g") 
    .transition()   
    .duration(300)                                  
    .attr("class", "x axis")                            
    .attr("transform", "translate(0," + height + ")")   
    .call(xAxis);                                       

svg.append('g')
    .transition()
    .duration(300)
    .attr('class', 'grid')
    .attr('transform', 'translate(0,' + height + ")")
    .call(make_x_axis()
        .tickSize(-height, 0, 0)
        .tickFormat("")
        )

svg.append('g')
    .transition()
    .duration(300)
    .attr("class", "grid")
    .call(make_y_axis()
        .tickSize(-width, 0, 0)
        .tickFormat("")
        )


svg.selectAll(".dot")
    .data(data)
    .enter().append("circle")
    .attr("class", "dot")
    .attr("r", 5)
    .attr("cx", function(d) { return x(d.startDateTime);})
    .attr("cy", function(d) { return y(d.Ranking * 3); })

});

Answer 1

zoomed is not defined. Your code is probably throwing an error at that line and then not executing anything that follows. zoomed would need to be defined as a function that describes what should happen when someone zooms on the graph, and would need to be defined before zoom . Or you can take out that line.