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

[Jean-Claude REPETTO]

Roger Oberholtzer wrote :
>
> 
> This looks promising. So, I have now tried:
> 
>    from = pj_init_plus(
>        "+proj=latlong "
>        "+ellps=WGS84");
> 
>    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 "
>        "+towgs84=52.684,-71.194,-13.975,-0.312,-0.1063,-0.3729,1.0191 "
>        "+no_defs");
> 
>      pj_transform(to, from, 1, 0, &le, &ln, &la);
> 
> And I see no difference at all. I use +towgs84 elsewhere, so I know it
> works like this. But, as I said, I see no difference.
> 

You have forgotten to add the +towgs84 parameter to the first 
projection. Alternatively, you can use "+datum=WGS84" instead of 
"+ellps=WGS84 +towgs84=0,0,0,0,0,0,0".