[Xastir] Since we are talking about dbfawk...an issue

[Tom Russo]

On Tue, Apr 21, 2009 at 09:49:50PM -0500, we recorded a bogon-computron collision of the <r.polivka at sbcglobal.net> flavor, containing:
> How do I go about ignoring the display of a particular feature?
> 
> I don't want the "x" displayed at the end of cul-de-sac's (MTFCC code 
> C3061).
> 
> What is the structure of the line to accomplish this? I am getting nowhere.

Two ways to do it:

If the majority of features in the shapefile are features you want to display,
set display_level to something reasonable in BEGIN_RECORD, and set it to 0
for features you don't want.  So in pointlm.dbfawk, if most features are
features you want displayed, leave display_level where it is in BEGIN_RECORD,
and add a dbfawk rule:

/MTFCC=C3061/ {display_level=0; next;}

Make sure that no earlier rule matches such a record first.  For example, if
you have 
/MTFCC=C3/ {display_level=512; next;}
(which you do), then you must put the C3061 rule earlier in the file so that
only those MTFCC=C3... that aren't C3061 get caught by the less specific rule.
Or modify MTFCC=C3 so it's more selective.  It is currently matching anything
that has an MTFCC that begins with C3.

Conversely, if the shapefile has mostly features you don't care about, set
display_level=0 in BEGIN_RECORD, and explicitly set it to something else for
each MTFCC code you *do* want displayed.

Alternatively, use ogr2ogr to create a shapefile that doesn't even have those
features in them.  This will speed things up tremendously if there are lots
of features being skipped over in dbfawk processing.  The up-front effort is
greater, but the payoff is faster map rendering.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
  In some cultures what I do would be considered normal. 
                                  -- Ineffective daily affirmation