graduated color symbols and mapserver

[Banister Trevor]

I was able to solve this to some extent by using the following expressions.
I'm not a regex guru, so some of these could sub optimal.

<Big ole' Kludge>

Suppose your range of numbers is 0-59 and you want 3 zones
Some of these expressions overlap, but it looks like the code is written so
the first matching expression encountered is enforced.


Zone 1: 2 classes to handle 0-19
[0-9]      Matches numbers from 0 to 9
[1-1][0-9] Matches numbers from 10 to 19

Zone 2: 1 class to handle 20-39
[2-3][0-9] 

Zone 3: 1 class to handle 40-59
[4-5][0-9] 

</Big ole' Kludge>

-----Original Message-----
From: Robert Chavez [mailto:rchavez at perseus.tufts.edu]
Sent: Monday, November 08, 1999 11:18 AM
To: mapserver-users at lists.gis.umn.edu
Subject: re: graduated color symbols and mapserver



You are right about the expressions, I haven't been able to come up with
anything that works.  Pre/Re classification would be possible, but the
files I'm working with are between 30 and 80 meg -- the dbf files are
just too large to pre/re classify easily with the tools I have at hand.

I'm toying with the idea about fooling around with the code to add
numeric expressions  -- to handle >,<,<=,>=, etc expressions.  I'm not
sure how useful this would be to the majority of map server users, but
maybe it's something that could be incorporated into a future version?

Rob


>That's what classes are for. Each class has it's
>own symbolization. The hard part is  the expression to use with ranges
of numbers. One easy thing to do is to pre-classify each shape in
arcview and then >use that column in mapserver class expressions.

>Steve