I can't speak for MI versions other than 6.5, but the MB works and the Map > Options... shows Area Units: square kilometers (which is hectares, of course).
IL Thomas GeoSciSoft - Perth, Australia > -----Original Message----- > From: Robert Crossley [mailto:[EMAIL PROTECTED] > Sent: Wednesday, 17 November 2004 1:15 PM > To: Dan Bowles > Cc: MapInfo List > Subject: Re: MI-L FW: Determining polygon areas and proportions within > polygons > > Dan, > > If you open your mapbasic window (Options Show Mapbasic window) and type: > > Set Area Units "hectare" > then enter, it will alter the system area units. > > r > > > On Wed, 17 Nov 2004 15:53:03 +1100, Dan Bowles <[EMAIL PROTECTED]> wrote: > > > Hi Soren > > > > You sent me this email some time ago on area and proportionoverlap > > commands, > > at the time I used other means, however, I'm now using areaoverlap to > > calculate areas of lots affected by flood constraints. It's working > quite > > beautifully, however, I'm struggling with the area units. Changing the > > map > > units from the Map>Options menu item does not seem to change the output > > units. Is there some way I can modify the command to set units to > > "hectare"? > > > > You're help is greatly appreciated. > > > > Regards > > Dan Bowles BSc > > GIS Officer > > Harper Somers O'Sullivan > > > > PO Box 428 > > HAMILTON NSW 2303 > > > > E [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > T 02 4961 6500 > > M 04 3834 8372 > > > > > > -----Original Message----- > > From: S�ren Breddam [mailto:[EMAIL PROTECTED] > > Sent: Thursday, 12 August 2004 5:13 PM > > To: 'Dan Bowles' > > Subject: SV: MI-L FW: Determining polygon areas and proportions within > > polygons > > > > > > Hi Dan, > > You do have options doing this with SQL: > > > > MB help: > > AreaOverlap( ) funtion: > > Purpose > > > > Returns the area resulting from the overlap of two closed objects. > > > > Syntax: > > AreaOverlap ( object1, object2 ) > > object1 and object2 are closed objects. > > > > Return Value > > A Float value representing the area (in MapBasic's current area units - > > use > > Set Area Units... to change this) of the overlap of the two objects. > > Example: > > Select AreaOverlap(PolygonTable1.Obj, PolygonTable2.Obj) , > > PolygonTable1.ID, > > PolygonTable2.ID > > Received: From PolygonTable1, PolygonTable2 > > Where PolygonTable1.Obj Intersects PolygonTable2.Obj > > Into a Noselect > > Browse * From a > > > > ProportionOverlap( ) function: > > Purpose > > Returns a number that indicates what percentage of one object is covered > > by > > another object. > > > > Syntax > > ProportionOverlap(object1,object2) > > object1 is the bottom object (not text or points) > > object2 is the top object (not text or points) > > > > Return Value > > A Float value equal to Area(Overlap(object1,object2) ) / Area(object1). > > > > > > > > HTH > > S�ren Breddam > > > > -----Oprindelig meddelelse----- > > Fra: Dan Bowles [mailto:[EMAIL PROTECTED] > > Sendt: 12. august 2004 02:14 > > Til: MapInfo-L > > Emne: MI-L FW: Determining polygon areas and proportions within polygons > > > > > > Sorry, original message didn't work with explanatory attachment. Hope > you > > understand without... > > > > -----Original Message----- > > From: Dan Bowles [mailto:[EMAIL PROTECTED] > > Sent: Thursday, 12 August 2004 9:35 AM > > To: MapInfo-L > > Subject: Determining polygon areas and proportions within polygons > > > > > > Hi all > > > > I have a very large data set of vegetation classifications (various > > coloured > > polygons in the base of the example map attached), in a GIS also > > including > > proposed vegetation corridors (blue polygons), national parks (green > > polygons) and state forests (brown polygons). The veg corridors, NPs and > > SFs > > do not intersect, however, the vegetation classification polygons > > intersect > > across all other layers. > > > > I need to determine how much area there is of each vegetation class in > > total > > and how much area of each class is contained within each of a number of > > distinct veg corridors (blue), and generally within NPs (green) and SFs > > (brown). I also need to determine percentages of each veg class within > > NPs, > > SFs and veg corridors compared to the entire area. > > > > I am having trouble getting MapInfo to automatically generate these > > statistics for me, any advice you could give would be fantastic. > > > > Thanks for your help > > > > Dan Bowles > > > > > > > > > > -- > ________________________________________________ > > Robert Crossley > > Agtrix P/L > 9 Short St > PO Box 63 > New Brighton 2483 > Far Southern Queensland > AUSTRALIA > > 153.549004 E 28.517344 S > > P: 02 6680 1309 > F: New Connection > M: 0419 718 642 > E: [EMAIL PROTECTED] > W: www.agtrix.com > W: www.wotzhere.com > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > Message number: 14085 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 14086
