[Qgis-developer] FW: Diagram improvements
Marco Hugentobler
marco.hugentobler at sourcepole.ch
Fri Aug 10 03:01:25 PDT 2012
Hi Matthias
Yes, that was exactly what I meant (I was not questioning the
usefullness of area proportional scaling).
Marco
Am 10.08.2012 11:30, schrieb Kuhn Matthias, Vermessung:
> Hi Andreas
>
> At the moment I plan to implement as follows:
>
> Default: Scale area
> => The user can define: a value v for an attribute a that will generate a diagram of diameter d
> A feature with v' = v/2 will generate a diagram with (d')^2 = (d)^2 / 2
>
> Option: Scale diameter
> => where v' = v/2 will generate a diagram with d' = d/2
>
>
> I think Marco was referring to my idea for the default version: to let the value v denote the area rather than the diameter. So d = sqrt(v/pi).
>
> --
> Matthias Kuhn
>
>
> ________________________________
>
> From: qgis-developer-bounces at lists.osgeo.org [mailto:qgis-developer-bounces at lists.osgeo.org] On Behalf Of Andreas Neumann
> Sent: Friday, August 10, 2012 11:08 AM
> To: Marco Hugentobler; qgis-developer at lists.osgeo.org
> Subject: Re: [Qgis-developer] FW: Diagram improvements
>
>
> Hm - I have to disagree here. The general opinion in thematic mapping is that you shpulf scale proportional to the area and not the diameter/radius. After all, if the attribute value of a feazure is 4 times larger than the att value of another feature the area of the circle/pie chart should be 4 times as large and not 16 or 8 times as large. In my opinion the area proportional behavior should be the default and the current behavior optional.
>
> Andreas
> --
> Diese Nachricht wurde von meinem Android-Mobiltelefon mit K-9 Mail gesendet.
>
>
>
>
> Marco Hugentobler <marco.hugentobler at sourcepole.ch> schrieb:
>
> >I think the first approach would be better for existing
> >projects, as the reference diagram (specified in the layer
> >config dialog) would keep its original size.
>
> Yes, I'm also in favor of the first approach. It is more intuitive to
> set the size of the diameter than the one of the area.
>
> Marco
>
> Am 10.08.2012 09:07, schrieb Kuhn Matthias, Vermessung:
> > Oops, clicked the wrong button. Here for the list:
> >
> >
> >> Hi Marco
> >>
> >> Good thoughts. A dimension more really justifies exponential scaling.
> >>
> >> For diagrams scaled by area, we should then use the specified
> >> diameter for the given attribute value and scale other
> >> diagrams according to this ratio.
> >> The other possibility would be to indicate indicate squared units.
> >&
> gt;
> >> I think the first approach would be better for existing
> >> projects, as the reference diagram (specified in the layer
> >> config dialog) would keep its original size.
> >> Whereas the second approach would lead to immediate resize in
> >> existing projects but it would be more comprehensible for the
> >> user that he is scaling by area.
> >>
> >> --
> >> Matthias Kuhn
> >>
> >>
> >>> -----Original Message-----
> >>> From: qgis-developer-bounces at lists.osgeo.org
> >>> [mailto:qgis-developer-bounces at lists.osgeo.org] On Behalf Of Marco
> >>> Hugentobler
> >>> Sent: Friday, August 10, 2012 8:04 AM
> >>> To: qgis-developer at lists.osgeo.org
> >>> Subject: Re: [Qgis-developer] Diagram improvements
> >>>
> >>> Hi Matthias
> >>>
> >>>> In my opinion
> this
> is a bug in the current version and should be
> >>>> changed without option
> >>> It will be good to have an additional option to scale
> >> proportional to
> >>> the area. But I think you should leave the option to scale the
> >>> diameter.
> >>> This was done on purpose, because the diagram size you
> >> specify is the
> >>> radius, not the area (and this again is similar to the symbology
> >>> system, where point symbol size is also diameter, not area). Btw, I
> >>> have read that there might also be cases where you want to scale
> >>> diagram sizes proportional to the volume (e.g. to display
> >> content of
> >>> lakes, etc.).
> >>>
> >>>
> >>> Regards,
> >>> Marco
> >>>
> >>>
> >>>
> >>> Am 09.08.2012 14:48, schrieb Kuhn Matthias
> ,
> Vermessung:
> >>>> Do you think circular diagrams (i.e. text and pie) need to
> >>> have an option to scale their radius instead of their area?
> >>>> In my opinion this is a bug in the current version and
> >>> should be changed without option as it overexagerates
> >> bigger values.
> >>> But maybe there is a reason to leave this choice to the user?
> >>>> --
> >>>> Matthias Kuhn
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: qgis-developer-bounces at lists.osgeo.org
> >>>>> [mailto:qgis-developer-bounces at lists.osgeo.org] On Behalf
> >>> Of Matthias
> >>>>> Kuhn
> >>>>> Sent: Tuesday, August 07, 2012 5:37 PM
> >>>>> To: Qgis Developer List
> >>>>> Subject: [Qgis-developer] Diagram improvem
> ents
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> I recently started an internship at Uster (a city in
> >>> Switzerland). My
> >>>>> job will mostly be to improve QGIS. I'm really looking
> >> forward to
> >>>>> this great opportunity.
> >>>>>
> >>>>> My first job is, to improve the diagrams. Any comments
> >> are highly
> >>>>> appreciated. (If you think something can be done better
> >>> differently,
> >>>>> if you think something is useless, if you are already working on
> >>>>> something or you know about somebody already working on
> >>> something, if
> >>>>> you wanna say thank you...)
> >>>>>
> >>>>> Here a short list of what I've got on my ToDo list.
> >>>>>
> >>>>> - Minimum size for diagrams (As an option, scale any
> >>> diagram smaller
> >>>>> than...): Done
> >>>>> - Text diagram: Center text better vertically (As an
> >> option): Done
> >>>>> - Charts are not placed on some polygons (e.g. banana
> >>> shaped polygons.
> >>>>> Should this be done with PAL library? Any help appreciated)
> >>>>> - Ordering: Draw smaller charts on top of bigger one instead of
> >>>>> hiding
> >>>>> (randomly?) colliding diagrams.
> >>>>> - Make diagrams area accurate! By now the radius instead
> >>> of area is
> >>>>> scaled.
> >>>>> - New diagram type: Bar chart
> >>>>> - New diagram option: Split diagrams. (Pie charts / Bar
> >>> charts e.g.
> >>>>> age
> >>>>> pyramid)
> >>>>>
> >>>>> If you're interested in the current state of work, have a
> >>> look at my
> >>>>> git repo [0] on master. Where it says done in the list above you
> >>>>> should be able to check it out.
> >>>>>
> >>>>> [0] https://github.com/matthias-kuhn/Quantum-GIS.git
> >>>>>
> >>>>> Regards,
> >>>>> I'm looking forward for comments
> >>>>>
> >>>>> Disclaimer: Sorry if you get this topic the second time.
> >> I thought
> >>>>> I'd written something about it yesterday, but couldn't
> >>> find it in my
> >>>>> history nor in the archives, so I'll repeat myself and
> >>> just believe,
> >>>>&g
> t; that
> I missed the send button when I tried to click it.
> >>>>>
> >>>>>
> ________________________________
>
>
> >>>>> Qgis-developer mailing list
> >>>>> Qgis-developer at lists.osgeo.org
> >>>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
> >>>>>
> >>>>
> ________________________________
>
>
> >>>> Qgis-developer mailing list
> >>>> Qgis-developer at lists.osgeo.org
> >>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
> >>>
> >>> --
> >>> Dr. Marco Hugentobler
> >>> Sourcepole - Linux & Open Source Solutions Weberstrasse 5,
> >>> CH-8004 Zürich, Switzerland marco.hugentobler at sourcepole.ch
> >>> http://www.sourcepole.ch
> <http://www.sourcepole.ch>
> Technical Advisor QGIS Project Steering
> >>> Committee
> >>>
> >>>
> ________________________________
>
>
> >>> Qgis-developer mailing list
> >>> Qgis-developer at lists.osgeo.org
> >>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
> >>>
> >
> ________________________________
>
>
> > Qgis-developer mailing list
> > Qgis-developer at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/qgis-developer
>
>
> --
> Dr. Marco Hugentobler
> Sourcepole - Linux & Open Source Solutions
> Weberstrasse 5, CH-8004 Zürich, Switzerland
> marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
> Technical Advisor QGIS Project Steering Committee
>
>
> ________________________________
>
>
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>
>
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer
--
Dr. Marco Hugentobler
Sourcepole - Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee
More information about the Qgis-developer
mailing list