GRID - Better doc and examples

[adube]

In the last days, while using the GRID feature for the first time, I followed the documentation and example to reproduce a grid using 4326 as projection.

When switching to 900913, MapServer timed out. It was due to the fact that I had set min/max interval values to low values such as 0.1. That value is in layer units, so when using 4326 I was in degrees. Switching to 900913 the units went to meters, and drawing 1 line per 0.1 meter caused the issue.

IMHO, a better documentation and seperate examples, one using degrees and the other using meters, would avoid doing this mistake.

[jmckenna]

@adube great. since you already have examples for 900913/meters, could you paste your examples here so we can add to the docs?

Also, when steve and I mentioned a ticket we meant regarding MapServer crashing (a small test case with one layer that produces a MapServer crash). This will have to be another ticket.

[adube]

LAYER
    NAME "grid"
    METADATA
        "DESCRIPTION" "Grid"
    END
    TYPE LINE
    STATUS ON
    CLASS
        NAME "Graticule"
        STYLE
            COLOR 0 0 0
            WIDTH 0.3
        END
        LABEL
            COLOR  0 0 0
            FONT "sans"
            TYPE truetype
            SIZE 6.5
            POSITION AUTO
            PARTIALS FALSE
            BUFFER 5
        END
    END
    PROJECTION
        "init=epsg:900913"
    END
    GRID
        LABELFORMAT '%.0fm'
        MAXARCS 10
        MININTERVAL 1000000
        MAXINTERVAL 1000000
        MAXSUBDIVIDE 2
    END
END

[jmckenna]

Committed updates to GRID document, that includes example map images.