Try the idiom below for the class breakouts. This will give you one
layer, with multiple classes, instead of 5 layers from the same data.
Order the CLASS definitions so that the most common class is listed
first. I believe (but don't know for sure) that your present
definition causes all of the geometry to be read 5 times (once for
each layer).
I think you can pull the CLASS MINSCALE/MAXSCALE up to the LAYER
level. Not sure what improvement that would have though.
One other thing I would suggest is preprocessing your EXPRESSION
line. Instead of computing it on the fly based on LOWER and UPPER,
compute a new column when the DBF is generated, which is 1 for -98 to
-104, 2 for -94 to -98, etc.
If this is not enough, consider creating two different levels of
polygon data, one coarse (for small scales) and one fine (for large
scales). This step made a big difference for me.
Hal
# ==============================================
# Layer: Propagations
# ==============================================
LAYER
GROUP "Propagations"
NAME "all propagations"
STATUS DEFAULT
TILEINDEX "propagations/tileindex"
TILEITEM "location"
TYPE POLYGON
# --------------------------------------------------
# Class: -98db to -104db
# --------------------------------------------------
CLASS
NAME "-98db to -104db"
EXPRESSION ([LOWER] >= -104 AND [UPPER] <= -98)
MINSCALE 0
MAXSCALE 1200000
STYLE
COLOR 255 128 0
OUTLINECOLOR 255 128 0
END
END
# --------------------------------------------------
# Class: -94db to -98db
# --------------------------------------------------
CLASS
NAME "-94db to -98db"
EXPRESSION ([LOWER] >= -98 AND [UPPER] <= -94)
MINSCALE 0
MAXSCALE 1200000
STYLE
COLOR 0 0 255
OUTLINECOLOR 0 0 255
END
END
[continue the class definitions...]
END
--
Hal Mueller [EMAIL PROTECTED]
Mobile Geographics LLC http://www.mobilegeographics.com/
