Beautiful, Alex. I was working on this idea myself, but your scripts is so much more elegant!
Thanks, Roger > On Nov 7, 2015, at 4:43 PM, Alex Tweedly <a...@tweedly.org> wrote: > > Actually, you should shorten the maths - makes it a bit more efficient > > > function getArea pPts > if line 1 of pPts <> line -1 of pPts then return 0 > put 0 into tArea > put empty into oldL > repeat for each line L in pPts > if oldL is not empty then > -- put item 1 of L - item 1 of oldL into dx > -- put item 2 of oldL + (item 2 of L - item 2 of oldL) / 2 > into avgY > -- put dx * avgY into thisArea > -- add thisArea to tArea > add (item 1 of L - item 1 of oldL) * ( item 2 of oldL + item 2 of L) > / 2 to tArea > end if > put L into oldL > end repeat > return abs(tArea) > > end getArea > > -- Alex. > > On 08/11/2015 00:09, Alex Tweedly wrote: >> Roger, >> >> try this (I've done some minimal testing, so do please check it ...) >> it assumes the polygon is closed >> >> function getArea pPts >> if line 1 of pPts <> line -1 of pPts then return 0 >> put 0 into tArea >> put empty into oldL >> repeat for each line L in pPts >> if oldL is not empty then >> put item 1 of L - item 1 of oldL into dx >> put item 2 of oldL + (item 2 of L - item 2 of oldL) / 2 into avgY >> put dx * avgY into thisArea >> add thisArea to tArea >> end if >> put L into oldL >> end repeat >> return abs(tArea) >> end getArea >> >> NB you could shorten it, but I left each math step separate to make it >> easier to debug / check >> >> -- Alex. >> >> On 07/11/2015 22:29, Roger Guay wrote: >>> Thanks very much, Scott. I do have a long points list that I would have to >>> manipulate even before apply this technique. I’m not looking forward to >>> that, but I may have to go this route. >>> >>> Cheers, >>> >>> Roger >>> >>> >>>> On Nov 7, 2015, at 12:05 PM, Scott Rossi <sc...@tactilemedia.com> wrote: >>>> >>>> It looks like this could translate to LC if you have the point locations >>>> of your polygon: >>>> >>>> https://www.mathsisfun.com/geometry/area-irregular-polygons.html >>>> >>>> >>>> Regards, >>>> >>>> Scott Rossi >>>> Creative Director >>>> Tactile Media, UX/UI Design >>>> >>>> >>>> >>>> >>>> On 11/7/15, 2:01 PM, "use-livecode on behalf of Roger Guay" >>>> <use-livecode-boun...@lists.runrev.com on behalf of i...@mac.com> wrote: >>>> >>>>> Can anyone think of an easy way of getting the area of an Irregular >>>>> polygon? >>>>> >>>>> Thanks, >>>>> >>>>> Roger >>>>> _______________________________________________ >>>>> use-livecode mailing list >>>>> use-livecode@lists.runrev.com >>>>> Please visit this url to subscribe, unsubscribe and manage your >>>>> subscription preferences: >>>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>>> >>>> >>>> _______________________________________________ >>>> use-livecode mailing list >>>> use-livecode@lists.runrev.com >>>> Please visit this url to subscribe, unsubscribe and manage your >>>> subscription preferences: >>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>> _______________________________________________ >>> use-livecode mailing list >>> use-livecode@lists.runrev.com >>> Please visit this url to subscribe, unsubscribe and manage your >>> subscription preferences: >>> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your subscription >> preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
