javascript - D3.js get nearest X & Y coordinates for Area Chart -


hi have area chart several x (year) & y (price) values. i've found there easy way x, y coodinates value chart when user clicks on 1 of point on line clicking outside line i.e. svg/chart-body area can provide x, y coordinates of planes rather data.

enter image description here

point on chart:

circles = c.svg().selectall 'circle.dot' circles.on 'click', (d) ->     console.log 'point', 'datum:', d

o/p:

point datum:  {x: fri feb 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 666}

point outside chart:

svg.on 'click', () ->     console.log 'svg', d3.mouse(@)

o/p:

svg [605.5, 394.5]

now there way nearest data coordinates when clicked on svg? e.g svg [605.5, 394.5] (something nearest [x, y] using)

{x: fri feb 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 666}

or other way translate svg x, y data x, y?

original data in form of,

[     {x: fri jan 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 666},     {x: fri feb 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 668},     {x: fri mar 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 700},     {x: fri apr 01 1980 00:00:00 gmt+0000 (gmt standard time), y: 750},     .     .     .     {x: fri dec 01 2010 00:00:00 gmt+0000 (gmt standard time), y: 2000},     .     .     . ]

http://bl.ocks.org/mikehadlow/93b471e569e31af07cd3

using d3.bisector,

var mouse = d3.mouse(this); var mousedate = xscale.invert(mouse[0]); var bisectdate = d3.bisector(function(d) { return d.x; }).left; var = bisectdate(data, mousedate); // returns index current data item  var d0 = data[i - 1] var d1 = data[i]; // work out date value closest mouse var d = mousedate - d0[0] > d1[0] - mousedate ? d1 : d0;  var x = xscale(d[0]); var y = yscale(d[1]);

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