ntv2 grid support

[steve-devore]

ntv2 grids, such as ntv2_0.gsb should be supported. ntv2 files are mentioned in Grid.java, but there's no corresponding parser for them.

[robertoricotti]

ntv2 grids, such as ntv2_0.gsb should be supported. ntv2 files are mentioned in Grid.java, but there's no corresponding parser for them.

Right now there still not a solution at this?

[pomadchin]

@robertoricotti should be supported, check #98

If smth is not working we'd probably need a more precise followup 👍

[robertoricotti]

Thanks, but is not explained how to use NTv2 . Adding into parameter will generate an Unsupported exception

[pomadchin]

@robertoricotti could you drop a piece of code you're trying to run? + if you could attach an ntv2 file, it'll help to debug.

Could be a 'feature' in our code unfortunately.

[robertoricotti]

try { GRECIA_2100 = crsFactory.createFromParameters("EPSG:2100", "+proj=tmerc +lat_0=0 +lon_0=24 +k=0.9996 +x_0=500000 +y_0=0 +ellps=GRS80 +towgs84=-199.87,74.79,246.62,0,0,0,0 +units=m " + "+nadgrids="+gridFile_GR+" +no_defs"); } catch (UnsupportedParameterException e) { Log.e("TestGre",Log.getStackTraceString(e)); GRECIA_2100=crsFactory.createFromName("epsg:"+DataSaved.S_CRS); } catch (InvalidValueException e) { Log.e("TestGre",Log.getStackTraceString(e)); GRECIA_2100=crsFactory.createFromName("epsg:"+DataSaved.S_CRS); } catch (UnknownAuthorityCodeException e) { Log.e("TestGre",Log.getStackTraceString(e)); GRECIA_2100=crsFactory.createFromName("epsg:"+DataSaved.S_CRS); } where: InputStream inputStrimGrid = getResources().openRawResource(R.raw.ostn15_ntv2_osgbtoetrs); File filgrd = new File(getCacheDir(), "ostn15_ntv2_osgbtoetrs.gsb"); try (OutputStream outputStream = new FileOutputStream(filgrd)) { byte[] buffer = new byte[1024]; int length; while ((length = inputStrimGrid.read(buffer)) > 0) { outputStream.write(buffer, 0, length); } gridFile_GR = filgrd.getAbsolutePath(); } catch (IOException e) { e.printStackTrace(); } [https://res.public.onecdn.static.microsoft/assets/mail/file-icon/png/zip_16x16.png]ntv2.zip<https://1drv.ms/u/c/822dfe52c89c9297/ESULMNCo7ttOiuBjm04BjFYBGWmXnEeXZ4SHCE5PW2zY8w>

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________________________________ Da: Grigory ***@***.***> Inviato: domenica 15 giugno 2025 22:50 A: locationtech/proj4j ***@***.***> Cc: robertoricotti ***@***.***>; Mention ***@***.***> Oggetto: Re: [locationtech/proj4j] ntv2 grid support (Issue #89) [https://avatars.githubusercontent.com/u/4929546?s=20&v=4]pomadchin left a comment (locationtech/proj4j#89)<#89 (comment)> @robertoricotti<https://github.com/robertoricotti> could you drop a piece of code you're trying to run? + if you could attach an ntv2 file, it'll help to debug. — Reply to this email directly, view it on GitHub<#89 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AVE4PKOGWYKAVTCIGMKA72L3DXMCBAVCNFSM6AAAAAB7JVWDSGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSNZUGY4DKNZYHA>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[pomadchin]

@robertoricotti ic, we have a bug apparently, let me get it fixed for you real quick.

[pomadchin]

@robertoricotti the PR is up: #121