Menu
▾
▴
Re: [JPP-Devel] some modification on CoordinateListMetrics class
|
From: Stefan S. <ss...@ge...> - 2013-02-15 14:51:38
|
Hi Peppe, > wms service and digit a linestring or polygon. On lat/lon maps > distance/area displayed on bottom bar are not true, Angles are not > corrected. ah, you are right > That is also what happens also with the AdvancedMeasure tools: if you > measure on a mm or cm map the output will always show "m". didn't know either. > > The only solution, most simple one, is an option panel which allows user > to choose a) Unit of the map and b) Unit of measures c) relative scale, > like gvsig or Kosmo. So user don't have to care about the crs. For that sounds like a good idea to me ;) cheers from Santiago (still here /here again), stefan > > > > > 2013/2/14 Stefan Steiniger <ss...@ge... <mailto:ss...@ge...>> > > Hi Peppe, > > I am not sure if you can do the changes without knowing about the SRID/ > project coordinate system. > For instance if someone loads a shapefile (or raster) with geographic > coordinates stored your change would still be showing meters (or do I > misunderstand your proposal?). Also, what happens if the user has for > instance everything in "cm" or "mm" as he may work with some really tiny > stuff (e.g., model trains?). What happens then? How will you be able to > display the right units when you add "m"? > > just some thoughts, > > cheers > stefan > > Am 14.02.13 14:21, schrieb Giuseppe Aruta: > > Immagine in linea 1 > > Hi all > > I want to do some modifications on class CoordinateListMetrics. This > > class is basically used to show angle/distance/area of a shape when a > > cursor tool is actived (drawing or measure tools) an the left side of > > buttom bar. > > > > This is the actual dispaly from CoordinatesListMetrics not modified > > Immagine in linea 1 > > > > > > And this are the display modifications I want to add > > Immagine in linea 2 > > > > As you can see there will some extra informations: > > - Distance will show the total length + length and (in the breaks) > > between last click and cursor position. I took this idea from > OpenJUMP > > the Merge > > - Display will show also the Azimuth between last click and the > cursor > > position > > - All measurements show International Standard Unit (meter for > lenght, > > square meter for area and Decimal Degrees for angles. All measure > will > > be calculate till 2 decimals > > > > If someone wants to see how it works, I adopted this way to > display info > > on my MeasureTools plugin building a modified copy of > > CoordinateListMetrics (and copies of conresponding classes > > Multiclicktool, PolygonTool, etc) > > > > ------------------------------------------------ > > > > Which are the pros > > - User has a better control on what is drawing (or measuring) and the > > can understand the scale of the shapes on the view, decide the > length of > > last drawn segment of a polygon, choose the angle and the azimuth of > > segments. > > - The information are more clear about that is going on "under the > > cursor tool" > > > > the cons > > a) These measure are shown only on SI units so some users who > work with > > Inperial Unit will feel disadvantaged > > 1st Solution - Actually we have a Measure on feet tool which > calculates > > only distance in feet (from meter unit maps) I will also add an extra > > tool on menu which will calculate also the area in Imperial Unit > (I ask > > to Landon which is the most common used square feet or else) > > 2nd solution - In the future I will study an option will allows > user to > > choose either map units (if necessary) and measure units on OpenJUMP. > > > > b) The actual algorithm on CoordinateListMetrics (included up to come > > Azimuth) work on Cylindrical projections and fail to calculate > > measurement when coordinates are expressed in lat/lon coordinates > and/or > > not cylindrical projections. > > Solution - In the up to come MeasureTool ther will be tools which > will > > calculate Area/Bearing using extra algorithms (MeasureTool 0.7 > already > > has a measure length tool using Thaddeus Vincenty's inverse formula). > > This is a partial solution and, more than this, I belive there > are not > > so many people who want to work on lat/lon map. > > > > Before doing these modifications I would like the opinion of the > other > > OpenJUMP community members. Regarding Translation, the only code > I will > > add will be "Azimuth". > > > > Regards > > > > Peppe > > > > > > > ------------------------------------------------------------------------------ > > Free Next-Gen Firewall Hardware Offer > > Buy your Sophos next-gen firewall before the end March 2013 > > and get the hardware for free! Learn more. > > http://p.sf.net/sfu/sophos-d2d-feb > > > > > > > > _______________________________________________ > > Jump-pilot-devel mailing list > > Jum...@li... > <mailto:Jum...@li...> > > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > _______________________________________________ > Jump-pilot-devel mailing list > Jum...@li... > <mailto:Jum...@li...> > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > > > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > > > > _______________________________________________ > Jump-pilot-devel mailing list > Jum...@li... > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > |