[Mapserver-users] help! newbie's question about displaying the shape file.

[Tyler Mitchell]

> Recently I installed the MapServer program, and I can run the demo 
itasca.
> I can display shape file from ArcView example in MapServer , but when I 
> run with my shape file, there are no image in the image area, just white 

> space, but the legend and the reference are showed.
> My shape file can be displayed in the ArcView environment.
> Is there some requirement about the shape file?
> The unit of extent is geographic.
> 
> /usr/local/apache2/htdocs/tmp can be written.

1) 
First, have a peek in the above folder and view all the image files.  Do 
you see your map in there at all?  You may want to delete them all and 
then re-run that mapserver app so you have fewer images to check out. 
There SHOULD be an image for the legend, scalebar and map.

2)
Can you confirm that you are actually getting a blank/white image file 
loading in your web page?  Or is the web page just not finding the graphic 
to show you?  There is a subtle but important difference here.  To find 
this out, try changing the background colour of your map - oh wait, you 
don't have one specified, add in under FONTSET:

IMAGECOLOR 100 100 100

That should give you a grey-ish background colour.  When you run the map 
again, do you see just a white map or do you see this grey?

3) If you don't see any colour at all, then your web page is not finding 
the image to load.  It could be because the image doesn't exist (that's 
what step (1) is meant to help discern).  The usual culprits are bad 
IMAGEPATH AND IMAGEURL parameters.  These may also be set in your initial 
html files - so check there too!

4) Is your dxregion data in lat/long?  When you view this in Arc view and 
move your cursor over the map, what kind of numbers do you get for 
coordinates in the map?  If you are not in lat/long units in your map 
data, then you either need to a) change the overall map projection for 
your map file or b) add a PROJECTION setting to the end of your LAYER 
definition.

Hope that helps.