matplotlib-users

[Matplotlib-users] pick markers only but not the connecting line

[C M <cmp...@gm...>]

I had been using a custom function (written originally by Jae-Joon and
modified a little by me...quite a long time back now) that was working to
allow point picking of markers, but *not* the line connecting them.
However, I've now discovered with the help of this list that the function I
am using has the disadvantage that if there are more than 100 data points,
I can't get the correct index for the picked marker (turned out not to be a
mpl bug:  https://github.com/matplotlib/matplotlib/issues/3124).

So I can just use the default pick event, but then the user can pick
anywhere on the connecting line, which is meaningless in this use--so I
don't want them to be able to pick on the connecting line.

My goal is to have a custom function that will serve *both* purposes:
allow picking the markers only, not the line, of a set of data of any
length while returning the correct index of that marker/data point.  But
the code in the custom function is mostly above my head, was written for
mpl 0.99 or so, and I don't know how to modify it to get both purposes
achieved.

I attach the current sample again, with the problematic custom picker
function, "contains_points()".  Thanks for any suggestions or help.

Che

Re: [Matplotlib-users] pick markers only but not the connecting line

[Eric F. <ef...@ha...>]

On 2014/06/07, 4:12 PM, C M wrote:
> I had been using a custom function (written originally by Jae-Joon and
> modified a little by me...quite a long time back now) that was working
> to allow point picking of markers, but *not* the line connecting them.
> However, I've now discovered with the help of this list that the
> function I am using has the disadvantage that if there are more than 100
> data points, I can't get the correct index for the picked marker (turned
> out not to be a mpl bug:
> https://github.com/matplotlib/matplotlib/issues/3124).
>
> So I can just use the default pick event, but then the user can pick
> anywhere on the connecting line, which is meaningless in this use--so I
> don't want them to be able to pick on the connecting line.

Why not just execute plot twice, once with the markers, with picking 
activated, and a second time with the line, with picking inactive (the 
default).

Eric

>
> My goal is to have a custom function that will serve *both* purposes:
> allow picking the markers only, not the line, of a set of data of any
> length while returning the correct index of that marker/data point.  But
> the code in the custom function is mostly above my head, was written for
> mpl 0.99 or so, and I don't know how to modify it to get both purposes
> achieved.
>
> I attach the current sample again, with the problematic custom picker
> function, "contains_points()".  Thanks for any suggestions or help.
>
> Che
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/NeoTech
>
>
>
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Re: [Matplotlib-users] pick markers only but not the connecting line

[C M <cmp...@gm...>]

On Sat, Jun 7, 2014 at 10:18 PM, Eric Firing <ef...@ha...> wrote:

> On 2014/06/07, 4:12 PM, C M wrote:
> > I had been using a custom function (written originally by Jae-Joon and
> > modified a little by me...quite a long time back now) that was working
> > to allow point picking of markers, but *not* the line connecting them.
> > However, I've now discovered with the help of this list that the
> > function I am using has the disadvantage that if there are more than 100
> > data points, I can't get the correct index for the picked marker (turned
> > out not to be a mpl bug:
> > https://github.com/matplotlib/matplotlib/issues/3124).
> >
> > So I can just use the default pick event, but then the user can pick
> > anywhere on the connecting line, which is meaningless in this use--so I
> > don't want them to be able to pick on the connecting line.
>
> Why not just execute plot twice, once with the markers, with picking
> activated, and a second time with the line, with picking inactive (the
> default).
>
> Eric
>

That is so simple, and I hadn't thought of it at all.  Thank you!  My only
concerns would be for slowness of plotting if there are a lot of points and
just code simplicity, and so if there could be some other way with a custom
function for the picker that would do this, I would probably prefer that.
But maybe neither of these are particularly important concerns.

Che

Re: [Matplotlib-users] pick markers only but not the connecting line

[Eric F. <ef...@ha...>]

On 2014/06/07, 5:03 PM, C M wrote:
>
>
>
> On Sat, Jun 7, 2014 at 10:18 PM, Eric Firing <ef...@ha...
> <mailto:ef...@ha...>> wrote:
>
>     On 2014/06/07, 4:12 PM, C M wrote:
>      > I had been using a custom function (written originally by
>     Jae-Joon and
>      > modified a little by me...quite a long time back now) that was
>     working
>      > to allow point picking of markers, but *not* the line connecting
>     them.
>      > However, I've now discovered with the help of this list that the
>      > function I am using has the disadvantage that if there are more
>     than 100
>      > data points, I can't get the correct index for the picked marker
>     (turned
>      > out not to be a mpl bug:
>      > https://github.com/matplotlib/matplotlib/issues/3124).
>      >
>      > So I can just use the default pick event, but then the user can pick
>      > anywhere on the connecting line, which is meaningless in this
>     use--so I
>      > don't want them to be able to pick on the connecting line.
>
>     Why not just execute plot twice, once with the markers, with picking
>     activated, and a second time with the line, with picking inactive (the
>     default).
>
>     Eric
>
>
> That is so simple, and I hadn't thought of it at all.  Thank you!  My
> only concerns would be for slowness of plotting if there are a lot of
> points and just code simplicity, and so if there could be some other way
> with a custom function for the picker that would do this, I would
> probably prefer that. But maybe neither of these are particularly
> important concerns.

I think you will find plotting two lines instead of one is not at all 
prohibitive with respect to speed; especially when you are zooming, so 
that the number of points being plotted is not so large.

As for simplicity, two calls to a standard function with almost the same 
arguments beats an arcane special-purpose function!

If you want to make your own picker, though, it looks like you could use 
a slight modification of Line2D.contains(); it would be just a matter of 
copying it and replacing this section

             # Check for collision
             if self._linestyle in ['None', None]:
                 # If no line, return the nearby point(s)
                 d = (xt - mouseevent.x) ** 2 + (yt - mouseevent.y) ** 2
                 ind, = np.nonzero(np.less_equal(d, pixels ** 2))
             else:
                 # If line, return the nearby segment(s)
                 ind = segment_hits(mouseevent.x, mouseevent.y, xt, yt, 
pixels)


with the code in the first option--that is, without checking the 
_linestyle.  You would also need to remove the first two lines after the 
docstring.

Eric

>
> Che
>
>
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/NeoTech
>
>
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Re: [Matplotlib-users] pick markers only but not the connecting line

[C M <cmp...@gm...>]

Great, thanks for all the help!


On Sun, Jun 8, 2014 at 12:09 AM, Eric Firing <ef...@ha...> wrote:

> On 2014/06/07, 5:03 PM, C M wrote:
> >
> >
> >
> > On Sat, Jun 7, 2014 at 10:18 PM, Eric Firing <ef...@ha...
> > <mailto:ef...@ha...>> wrote:
> >
> >     On 2014/06/07, 4:12 PM, C M wrote:
> >      > I had been using a custom function (written originally by
> >     Jae-Joon and
> >      > modified a little by me...quite a long time back now) that was
> >     working
> >      > to allow point picking of markers, but *not* the line connecting
> >     them.
> >      > However, I've now discovered with the help of this list that the
> >      > function I am using has the disadvantage that if there are more
> >     than 100
> >      > data points, I can't get the correct index for the picked marker
> >     (turned
> >      > out not to be a mpl bug:
> >      > https://github.com/matplotlib/matplotlib/issues/3124).
> >      >
> >      > So I can just use the default pick event, but then the user can
> pick
> >      > anywhere on the connecting line, which is meaningless in this
> >     use--so I
> >      > don't want them to be able to pick on the connecting line.
> >
> >     Why not just execute plot twice, once with the markers, with picking
> >     activated, and a second time with the line, with picking inactive
> (the
> >     default).
> >
> >     Eric
> >
> >
> > That is so simple, and I hadn't thought of it at all.  Thank you!  My
> > only concerns would be for slowness of plotting if there are a lot of
> > points and just code simplicity, and so if there could be some other way
> > with a custom function for the picker that would do this, I would
> > probably prefer that. But maybe neither of these are particularly
> > important concerns.
>
> I think you will find plotting two lines instead of one is not at all
> prohibitive with respect to speed; especially when you are zooming, so
> that the number of points being plotted is not so large.
>
> As for simplicity, two calls to a standard function with almost the same
> arguments beats an arcane special-purpose function!
>
> If you want to make your own picker, though, it looks like you could use
> a slight modification of Line2D.contains(); it would be just a matter of
> copying it and replacing this section
>
>              # Check for collision
>              if self._linestyle in ['None', None]:
>                  # If no line, return the nearby point(s)
>                  d = (xt - mouseevent.x) ** 2 + (yt - mouseevent.y) ** 2
>                  ind, = np.nonzero(np.less_equal(d, pixels ** 2))
>              else:
>                  # If line, return the nearby segment(s)
>                  ind = segment_hits(mouseevent.x, mouseevent.y, xt, yt,
> pixels)
>
>
> with the code in the first option--that is, without checking the
> _linestyle.  You would also need to remove the first two lines after the
> docstring.
>
> Eric
>
> >
> > Che
> >
> >
> >
> >
> >
> >
> ------------------------------------------------------------------------------
> > Learn Graph Databases - Download FREE O'Reilly Book
> > "Graph Databases" is the definitive new guide to graph databases and
> their
> > applications. Written by three acclaimed leaders in the field,
> > this first edition is now available. Download your free book today!
> > http://p.sf.net/sfu/NeoTech
> >
> >
> >
> > _______________________________________________
> > Matplotlib-users mailing list
> > Mat...@li...
> > https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/NeoTech
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>