[GRASS-dev] .g.proj datum_trans (5514)

[Martin Landa]

Hi,

2016-04-02 12:24 GMT+02:00 Martin Landa <landa.martin at gmail.com>:
>>> Is there anything I am doing wrong or it's a bug? Thanks, Martin
>>
>> This part is still buggy.
>
> I see, I will try to take a look during this weekend. Ma

Ok, it's `-t` flag again.

$ g.proj epsg=5514 datumt=-1
---
1
Used in whole S_JTSK region
towgs84=589.000,76.000,480.000
Default 3-Parameter Transformation (May not be optimum for older
datums; use this only if no more appropriate options are available.)
---
2
Used in Czech Republic
towgs84=570.8,85.7,462.8,4.998,1.587,5.261,3.56
Accuracy about 1m
---
3
Used in Czech Republic
towgs84=572.213,85.334,461.94,-4.9732,-1.529,-5.2484,3.5378
Accuracy about 1m
---
4
Used in Slovakia
towgs84=485,169.5,483.8,7.786,4.398,4.103,0
Accuracy about 1m

But

g.proj epsg=5514 datumt=2 -p
-PROJ_INFO-------------------------------------------------
...
towgs84    : 589,76,480,0,0,0,0

still gives me default datum transformation params.

Adding `-t` flags leads to correct result.

g.proj epsg=5514 datumt=2 -tp
-PROJ_INFO-------------------------------------------------
...
towgs84    : 570.8,85.7,462.8,4.998,1.587,5.261,3.56
...

I don't know why `-t` flags is neeed here, selected parameters by
`datumtrans` should be enough here.

Any idea? Thanks. Martin

-- 
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa