[Proj] Problems with EOV for Hungary (1972 Egyseges Orszagos Vetuleti)

[Jean-Claude REPETTO]

Roger Oberholtzer wrote:
> 
>    to = pj_init_plus(
>                 "+proj=somerc "
>                 "+lat_0=47.14439372222222 "
>                 "+lon_0=19.04857177777778 "
>                 "+k=0.99993 "
>                 "+x_0=650000 "
>                 "+y_0=200000 "
>                 "+ellps=GRS67 "
>                 "+units=m "
>                 "+no_defs");
> 
>      pj_transform(to, from, 1, 0, &le, &ln, &la);
> 
> When I run some test data, I am always 80 some meters away. For example:

Hello,

You are missing the +towgs84 parameter, which is necessary if you want 
PROJ.4 to perform a datum change.

Jean-Claude