Search code examples
javascriptlined3.js

D3 line acting as a closed path

Update: Here's an example of the issue - http://jsfiddle.net/Hffks/2/

I'm trying to use D3 to code a line graph and my line is being closed at the end, by which I mean it acts as a closed path where the first and last points are the same. My data comes in the following JSON format:

[ entityA : [ { time : 1230000,  // time since epoch
             attribute1 : 123 // numeric value 
             attribute2 : 123 // numeric value
            },
              { time : 1230010,  // time since epoch
              attribute1 : 123 // numeric value 
              attribute2 : 123 // numeric value
            } ],
  entityB : [ { ... // same format as above
  ...
 ]

I'm using a standard declaration of a line (d3.svg.line with a function for x and y):

var line = d3.svg.line()
        .x(function(d) {
            return x_scale(d.c_date)); 
        })
        .y(function(d) { 
            return y_scale(d.total); 
        });

Then inside a for loop that iterates over the entities I'm appending a "svg:path":

canvas.append("svg:path")
            .attr("d", line(data[entity]))

Everything else about the graph works: the points are correctly placed, I have multiple independent lines per entity, the axes are drawn, etc. However, each independent line acts as a closed path.

Thanks for in advance for any help!

Solution

  • Paths are filled by default. If you set fill to "none" and stroke to "black" you'll see that the path is not closed, it just appeared to be.

    Working fiddle: http://jsfiddle.net/Hffks/3/