cgcai/svy21

A Free and Open Source Library to convert between Lat/Lon and SVY21.

svy21's Issues

Conversion not accurate

Converting X,Y from onemap is totally off.

Using the script calculates wrong coordinates from :
http://www.onemap.sg/api/help/HTMLSource/ConvertCords.aspx

different result using c++ and python

Hi guys,

I use the following code in c++:

SVY21 svy21;
double northing, easting;
double lat, lon;
easting = 12056.9149612;
northing = 37621.664783;
svy21.SVY21ToLatLon(northing, easting, &lat, &lon);
printf("%lf %lf\n", lat, lon);

Result: 1.356507 103.159780

I use the python:

cv = SVY21()
(N, E) = (37621.664783, 12056.9149612)
(lat, lon) = cv.computeLatLon(N, E)
(lat, lon)
(1.3565065593611545, 103.69005934636358)

Different results (longitude) and the Python one is quite accurate but the c++ one is not. Anything happened?

Deprecated, Use proj4

Javascript example:

    import proj4 from 'proj4'
    proj4.defs("EPSG:3414","+proj=tmerc +lat_0=1.366666666666667 +lon_0=103.8333333333333 +k=1 +x_0=28001.642 +y_0=38744.572 +ellps=WGS84 +units=m +no_defs");
    var coords = proj4("EPSG:3414").inverse([43387.0213,40582.6686]);
    console.log(coords)

Projection details were retrieved from https://epsg.io/3414
https://github.com/proj4js/proj4js

License is missing

Hi,
What is exact license of this library? Can it be used in closed-source projects?