[Qgis-user] labelling by attribute

[Luca Galuppini]

@ Fred: thank you for the workaround you have suggested, but i need
something "clean" as my project is so much "crowdy" as it is now,
duplicating layers or breaking them by attribute is something i would keep
as last resource...

@ Tom: this is what i was looking for, i'm not familiar with this kind of
expressions (is it SQL?) and surely next versions of qgis need some GUI for
this function, even if probably the expression thing grants more
flexibility. anyway, how do you know what the program "expects" after the
"THEN"? what is the correct argument for bold, or italics, or a different
font color?

2015-06-20 3:20 GMT+02:00 Tom Lennon <tolennon at gmail.com>:

> Hi Lucas:
> You can use the "data defined override" to set the text size based on your
> classes.
> Use the fancy "E" under Layer Properties > labels > size.
> The program expects a number which will become the size.
>
> If the class in your data base is called "class" and it happens to be a
> number usable as the text size just put "class" in the override.
>
> If "class" is a ranking number ( like 1 - 6, with 1 being the largest
> population and 6 the least) then enter 13 - "class" in the override to get
> 7 for least and 12 for largest "class".
>
> if "class" is a population number then enter a CASE expression like this:
> CASE
> WHEN  "class" > 1000000 THEN  12
> WHEN  "class" > 750000 AND  "class" < 1000000 THEN  11
> WHEN  "class" > 500000 AND  "class" < 750000   THEN  10
> WHEN  "class" > 250000 AND  "class" < 500000   THEN  9
> WHEN  "class" > 100000 AND  "class" < 250000   THEN  8
> ELSE     7
> END
>
> The overrides can be used to also change font or type style based on data
> values as well.
>
>
> On Fri, Jun 19, 2015 at 5:52 PM, Fred Lali <lalifred at gmail.com> wrote:
>
>> Lucas, just copy the same layer and paste in the same canvas n the label
>> them with different fonts!
>>
>>
>>
>> For God and My Country
>> Consultant in: GIS,Forestry and Environment @ Earth Consult(U) Ltd.
>> CCRP GIS Support-Uganda
>> (The MCKNIGHT Foundation)
>>
>> Rotarian at RC. Bweyogerere Namboole
>> Mob: 0772/0752-841118
>> Sent from Lumia Windows phone
>> ------------------------------
>> From: Luca Galuppini <luca.galuppini at gmail.com>
>> Sent: ‎20/‎06/‎2015 00:28
>> To: qgis-user at lists.osgeo.org
>> Subject: [Qgis-user] labelling by attribute
>>
>> i'm sorry for posting a lot of newbie questions but tutorials are not so
>> clear about this:
>> i have to label a point feature with different font size or style
>> depending on an attribute in the table (for example, i have cities grouped
>> in classes by their importance, and i want the bigger cities to have bigger
>> label size).
>> this is really straight forward in arcgis but i really can't find this
>> option in qgis 2.8.2, at least not in a place when one can find it easily.
>> i expect i should have something similar to symbol by category, but
>> nothing like that is in the label menu...
>>
>> _______________________________________________
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>> Qgis-user at lists.osgeo.org
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>>
>
>
>
> --
> tolennon at gmail.com
>
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