AW: [mapserver-dev] RFC49: mapfile simplifications andsymbologyenhancements

Mon Dec 8 18:13:31 EST 2008

I kinda like this approach since it would already be familiar to folks
(I think Steve W. was lobbying for this back when I proposed the binding
support. Would just have to document a couple
of standard "recipes" for users.

Steve

>>> On 12/5/2008 at 9:43 AM, in message
<49394C1D.5040108 at geoanalytic.com>, Brent
Fraser <bfraser at geoanalytic.com> wrote:
> Steve,
> 
>   Perhaps a compromise would be to allow some simple arithmetic
expressions 
> (like the ones in the FILTER keyword?), such as:
> 
>     SIZE  ( 18 + [poptotal] * (( 43-18)/(5000-30000))  )
> 
> In my case, I've got ANGLEs in a shapefile (ok, 13,000 shapefiles) as

> "standard" angles (0=x-axis, + is ccw) but Mapserver likes azimuths 
> (0=y-axis, + = cw).  I'd rather not add another field to the
shapefile, to 
> minimize the data management problems.
> 
> Brent Fraser
> 
> 
> Steve Lime wrote:
>> MapServer's interpretation of size through an attribute binding is
>> literal. That is, the value
>> in the column is used as the size in pixels. Since you set a max
scale
>> it makes sense you
>> see all size 43.
>> 
>> In that case your suggestion makes sense although I'm not sure the
best
>> way to implement.
>> 
>> I don't think strictly following the charting syntax makes sense
since
>> we'd then have two ways
>> to bind attributes which would get confusing. Any ideas?
>> 
>> Steve 
>> 
>>>>> "Karsten Hoffmann" <khoffmann at igf.uni-osnabrueck.de> 12/04/08
5:59
>> AM >>>
>> Hi Thomas,
>> 
>> I’m not sure if I understand what you mean. 
>> 
>> I tried your proposition with Mapserver 5.2. But all circles have
the
>> same
>> size (43 pixel):
>> 
>> LAYER
>>   NAME        population
>>   TYPE         POINT
>>   STATUS    default
>>   DATA         Lan_point.shp
>>   CLASS
>>     NAME 'Population'
>>     STYLE
>>         SYMBOL 'circle'
>>         SIZE [poptotal]
>>         MINSIZE 18
>>         MAXSIZE 43
>>         OUTLINECOLOR 0 0 0
>>         COLOR 0 0 255
>>     END
>>   END
>> END
>> 
>> The sizes of the circles should vary depending on the number of
>> habitants. I
>> don’t want to preprocess the population data. At the moment I
calculate
>> the
>> sizes of the circles by myself and write them in a new field
(pop_size)
>> in
>> the attribute table. 
>> The Style is then:
>> 
>>     STYLE
>>         SYMBOL 'circle'
>>         SIZE [pop_size]
>>         OUTLINECOLOR 0 0 0
>>         COLOR 0 0 255
>>     END
>> 
>> The population varies from around 5000 to 30000 habitants. The sizes
of
>> the
>> circles should vary from 18 to 43.
>> 
>> With a Chart-Layer it is very comfortable to define this:
>> 
>> PROCESSING "CHART_SIZE_RANGE=poptotal 18 43 5000 30000"
>> 
>> But I don’t want to have a pie chart with slices here just a
simple
>> filled
>> circle.
>> 
>> Best,
>> Karsten
>> 
>> 
>> -----Ursprüngliche Nachricht-----
>> Von: thomas bonfort [mailto:thomas.bonfort at gmail.com] 
>> Gesendet: Donnerstag, 4. Dezember 2008 12:18
>> An: Karsten Hoffmann
>> Cc: mapserver-dev Mailing List
>> Betreff: Re: [mapserver-dev] RFC49: mapfile simplifications and
>> symbologyenhancements
>> 
>> karsten, if I understant your request correctly, MapServer already
has
>> that:
>> 
>> STYLE
>>  SYMBOL "circle"
>>  SIZE [population]
>>  MINSIZE 3
>>  MAXSIZE 20
>> END
>> 
>> you'll probably want to preprocess the [population] in your data
>> request (to add steps, or scaling)
>> 
>> regards,
>> thomas
>> 
>> On Thu, Dec 4, 2008 at 11:45, Karsten Hoffmann
>> <khoffmann at igf.uni-osnabrueck.de> wrote:
>>> Dear developers,
>>>
>>> I would like to ask for another feature which could be perhaps
>> included in
>>> this RFC.
>>>
>>> Since version 5.2 it's possible to bind the size of pie charts to
an
>>> attribute (https://trac.osgeo.org/mapserver/ticket/2136): 
>>> PROCESSING "CHART_SIZE_RANGE=itemname minsize maxsize minval
maxval"
>>>
>>> This would also be useful for point symbols as simple diagrams
without
>>> slices or bars. The idea is to have a symbol, let's say a filled
>> circle or
>>> square, which varies continuously in size. The size is bound to an
>> attribute
>>> for example the absolute number of habitants of different
countries.
>>>
>>> This would be a useful feature for thematic mapping. Is it possible
to
>>> implement this?
>>>
>>> Best regards
>>> Karsten Hoffmann
>>>
>>>
>>> -----Ursprüngliche Nachricht-----
>>> Von: mapserver-dev-bounces at lists.osgeo.org 
>>> [mailto:mapserver-dev-bounces at lists.osgeo.org] Im Auftrag von
thomas
>> bonfort
>>> Gesendet: Donnerstag, 4. Dezember 2008 11:18
>>> An: mapserver-dev Mailing List
>>> Betreff: [mapserver-dev] RFC49: mapfile simplifications and
>>> symbologyenhancements
>>>
>>> Hi,
>>>
>>> Not sure if the changes warrant a full blown RFC, but as there
quite a
>>> number of them I've regrouped them.
>>>
>>>
>>
http://trac.osgeo.org/mapserver/browser/trunk/docs/development/rfc/ms-rfc-49

>>> .txt
>>>
>>> These changes are/were all in RFC45, but were extracted to keep
things
>>> moving on as some of the stuff in rfc45 lacks funding in the near
>>> future.
>>>
>>> You can see it in action here on openstreetmap data:
>>> http://mapserverosm.s3.amazonaws.com/parisosm.html 
>>> nothing that's impossible to do with the current mapfile keywords
>>>> greatly simplified, as e.g. roads are mostly defined with a
single
>>> class whatever the scale (using a combination of sizeunits at the
>>> layer level, and min/max width and min/max scale at the style
level)
>>>
>>> regards,
>>> thomas
>>> _______________________________________________
>>> mapserver-dev mailing list
>>> mapserver-dev at lists.osgeo.org 
>>> http://lists.osgeo.org/mailman/listinfo/mapserver-dev 
>>>
>>>
>> 
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