On Monday, October 17, 2016 at 3:37:51 PM UTC-5, Jean Niklas L'orange wrote:
>
> Hi Marshall,
>
> On 17 October 2016 at 07:54, Mars0i <mars...@logical.net <javascript:>>
> wrote:
>
>> Looks very nice! Thanks Jean Niklas. I've been using Incanter for
>> charts, which has been fine so far for my needs, but clj-xchart looks like
>> it will make it easier to make nicer charts, and it would avoid loading
>> much of Incanter when you don't need some of the other things Incanter
>> provides. (I also use nvd3 to generate charts in a browser with
>> Clojurescript.)
>>
>
> Thanks! This was also parts of the rationale for clj-xchart as well:
> Incanter is great, but it feels a bit strange to drag in both json and csv
> dependencies if you only need to plot some charts.
>
>
>> But if I'm plotting several sequences of y values that are embedded in a
>> sequence of maps or vectors, each with several y values for the same x, I
>> wonder if it could be more to efficient pass the entire complex sequence to
>> the plotting function at once, and only provide one set of x values if all
>> of the y values will share the same x's. If the plotting function extracts
>> the y values as it reads through the sequence of maps/vectors, and needs
>> only one sequence of x's, then only two sequences are realized.
>>
>> Maybe this is an unusual need, at present, but as Clojure is used for
>> more scientific applications, it might become more common.
>>
>
> XChart (and consequently clj-xchart) can take the same x-axis as input. So
> you can reuse the same x values instead of creating 3 distinct but
> identical ones:
>
> (let [x [1 2 3]
> y1 [1 2 3]
> y2 [2 4 6]
> y3 [3 6 9]]
> (c/xy-chart {"y1" {:x x :y y1}
> "y2" {:x x :y y2}
> "y3" {:x x :y y3}}))
>
> I don't think this is unique to clj-xchart though, the same should apply
> to Incanter/JFreeChart.
>
Right. I don't know why I didn't think of that. Good idea.
Unfortunately, clj-xchart will indirectly realise almost all lists it is
> given, as it calls .size() on them to ensure that the X/Y/error lists are
> identical in size. It will also walk the lists to find the size/scale of
> the chart to plot. I'm not sure if there's a way around that, except
> perhaps if one pin the boundaries of the plot axes.
>
> That being said, it doesn't seem like a bad idea to provide some sort of
> efficient view over data to avoid creating a new list that will be realised
> with the exact same data in another list. I made an issue
> <https://github.com/hyPiRion/clj-xchart/issues/5> on this, it shouldn't
> be too hard to implement either.
>
Great.
> For what it's worth, I've had the same "issue" with large datasets as well
> (10-20M elements). In my case there isn't that much interesting to look at
> except the occational outlier, or if you have values which differ extremely
> from one datapoint to another.
>
> What I tend to do is rebin/shrink the data set, typically by computing the
> average/max value of partitions (after filtering away outliers), depending
> on what I need to plot. I have a small section in the "Gotchas" section
> named Many Datapoints
> <https://github.com/hyPiRion/clj-xchart/blob/master/docs/tutorial.md#many-datapoints>
> (bottom
> of the page) which has a couple of lines on how one can do that. I haven't
> found a good generic interface for it yet, so it's not provided by
> clj-xchart as of now.
>
Yes, good idea for some situations. For my present project, it's OK to
simply use every 10th or 100th point, even when the data is wildly random,
but sometimes I want to see them all. Other data elements are roughly
continuous, so it's no problem to sample every nth point.
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
