Scales Using Time- d3.min or Sorting - data[0]

[Jammer Jamski]

Hi All,

I'm just trying to figure out how best to manipulate some data prior to visualising.

I'm stuck on getting this to work and from doing some Googling it appears that a lot of people don't even attempt it this way and it started me wondering.  Currently I'm trying to get this to work:

    var x = d3.time.scale()
        .domain(
            d3.min(plotCollection, function (plot) { return d3.min(plot.date, function (dateVar) { dateVar.date; }); }),
            d3.max(plotCollection, function (plot) { return d3.max(plot.date, function (dateVar) { dateVar.date; }); })
        )
        .range([0, width]);

But it seems a lot of people just sort the array and then pick the first and last items in order to build the Domain scale.

Which is "right"?

I know that is a subjective and (s'cus the pun) domain related issue but if you have a large data set which would be the method of choice?

I guess my lack of knowledge on Javascript doesn't help here.  If you sort an array is a new array generated and then populated or does it operate only on the indexing of the original array?

Cheers,

Jammer

[Jammer Jamski]

I've gotten this working using:

    var x = d3.time.scale()
        .domain(d3.extent(data, function(d) { return d.date; }))
        .range([0, width]);

This seem pretty nice syntactically but I would be interested to know if the sorting approach is somehow better?  Or is the sorting method simply wrapped up in d3.extent( ...)?

Cheers,

Jammer