[udig-devel] A unique colour for each Feature

[Jody Garnett]

Hi Andrea - now we are into scientific visualization, colour theory and 
in short how to lie with maps 
(http://www.amazon.com/How-Maps-2nd-Mark-Monmonier/dp/0226534219 ).

So I totally understand your request (and have made plenty of maps like 
that myself) - but one thing I have learned
is that they do not communicate anything. If your point is that all the 
parishes are *different* then you can do that
more effectively by coloring them the same and using a thicker 
contrasted border (border emphasis the difference rather then the
color changes - an easy example is that somewhere on your map of Italy 
two parishes will end up with colours so close that
the eye will not be able to notice the difference and this they will be 
joined visually).

But enough of my rant - you can make up additional style configuration 
pages - including one that will map from FeatureID.hashCode() to
a colour. I recommend calling the page "Unique" or "Random" - using 
FeatureID will keep the mapping stable as people zoom in or pan, it
will also allow the style page to be used for all FeatureTypes (even 
those without an ID column).

Oh and do me a favour - use a larger border when setting up that Style.

I love the smell of cartography in the morning.
Cheers,
Jody
> In fact I love those colorschemes.
> What I was trying to explain is that if the grouping is by bins, then,
> just to do a simple example:
>
> I have a shapefile with all the parishes of Italy. About 1000 and some
> more. Let's say I have just an ID attribute and the IDs were taken from
> north to south. Now I want to render them, showing them all different.
> With the actual approach it takes the first 80 and colors them the same
> way and so on. The result is a map of Italy in stripes, instead of an
> arlecchino as I wanted to.
>
> Ciao
> Andrea
>
>
>   
>> Cheers,
>> Jody
>>     
>>> Andrea
>>>
>>>
>>>
>>>
>>> Jesse Eichar wrote:
>>>  
>>>       
>>>> Hi,
>>>>
>>>> I am releasing RC9 right now which has fixed a number of critical
>>>> problems loading images that were uncovered in RC8.  You can try it
>>>> out at:
>>>>
>>>> Windows:
>>>> <http://udig.refractions.net/downloads/RC9/udig-1.1.RC9-unofficial.exe>
>>>> Linux:
>>>> <http://udig.refractions.net/downloads/RC9/udig-1.1.RC9-unofficial.linux.gtk.x86.zip>
>>>>
>>>> Mac OSX:
>>>> <http://udig.refractions.net/downloads/RC9/udig-1.1.RC9-unofficial.macosx.carbon.x86.zip>
>>>>
>>>>
>>>> For ECW I think that we have to wait for the gdal backed support which
>>>> is under development but I don't l know when it will be ready for "real"
>>>> use.  Send an email to the geotools list for an answer on that.
>>>>
>>>> Finally if there is no .prj then you will probably need RC9 because it
>>>> allows you to tell a layer what the projection is.
>>>>
>>>> Jesse
>>>>
>>>> On 5-Feb-07, at 4:44 PM, Shaun Kolomeitz wrote:
>>>>
>>>>    
>>>>         
>>>>> Thanks Adrian and Jesse,
>>>>>
>>>>> I was using uDIG 1.1.0 RC8 and wound back to a stable release (1.0.6).
>>>>>
>>>>> It works OK now (for adding JPEG or GeoTIFF images), but seems to have
>>>>> a real problem rendering vectors (lines or polys) over the top.
>>>>>
>>>>> This may be because there is no PRJ file associated with either the
>>>>> SHP or JPG/TIF images.
>>>>>
>>>>> Is there any estimate for when ECW “may” be available ?
>>>>>
>>>>> Thanks in advance.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Shaun
>>>>>
>>>>>
>>>>> ___________________________
>>>>>
>>>>> Disclaimer
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> WARNING: This e-mail (including any attachments) has originated from a
>>>>> Queensland Government department and may contain information that is
>>>>> confidential, private, or covered by legal professional privilege, and
>>>>> may be protected by copyright.
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> You may use this e-mail only if you are the person(s) it was intended
>>>>> to be sent to and if you use it in an authorised way. No one is
>>>>> allowed to use, review, alter, transmit, disclose, distribute, print
>>>>> or copy this e-mail without appropriate authority. If you have
>>>>> received this e-mail in error, please inform the sender immediately by
>>>>> phone or e-mail and delete this e-mail, including any copies, from
>>>>> your computer system network and destroy any hardcopies.
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> Unless otherwise stated, this e-mail represents the views of the
>>>>> sender and not the views of the Environmental Protection Agency.
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> Although this e-mail has been checked for the presence of computer
>>>>> viruses, the Environmental Protection Agency provides no warranty that
>>>>> all viruses have been detected and cleaned. Any use of this e-mail
>>>>> could harm your computer system. It is your responsibility to ensure
>>>>> that this e-mail does not contain and is not affected by computer
>>>>> viruses, defects or interference by third parties or replication
>>>>> problems (including incompatibility with your computer system).
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> E-mails sent to and from the Environmental Protection Agency will be
>>>>> electronically stored, managed and may be audited, in accordance with
>>>>> the law and Queensland Government Information Standards (IS31, IS38,
>>>>> IS40, IS41 and IS42) to the extent they are consistent with the law.
>>>>>
>>>>>
>>>>>  
>>>>>
>>>>> ___________________________
>>>>>
>>>>>  
>>>>> _______________________________________________
>>>>> User-friendly Desktop Internet GIS (uDig)
>>>>> http://udig.refractions.net
>>>>> http://lists.refractions.net/mailman/listinfo/udig-devel
>>>>>       
>>>>>           
>>>> ------------------------------------------------------------------------
>>>>
>>>> _______________________________________________
>>>> User-friendly Desktop Internet GIS (uDig)
>>>> http://udig.refractions.net
>>>> http://lists.refractions.net/mailman/listinfo/udig-devel
>>>>     
>>>>         
>>>   
>>>       
>>     
>
>