# proj4-hs-bindings

Haskell bindings for the Proj4 C dynamic library.

 Latest on Hackage: 0.1

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

Haskell bindings for the Proj.4 map projection C library.

You need to have Proj.4 already installed as a shared library.

Example transformations (from http://www.mysqludf.org/lib_mysqludf_fPROJ4/):

``````import Geo.Proj4

lon0 = 22.350 * pi / 180 -- Test longitude in radians.
lat0 = 40.084 * pi / 180 -- Test latitude in radians.
alt0 = 2843 -- Test altitude in meters.

-- | Test projection:
pj = newProjection "+proj=utm +zone=34"

-- | Another test (null, e.g. cylindrical) projction:
pj0 = newProjection "+proj=latlong +ellps=clrk66"

-- | A projection of our test longitude & latitude, using @pj:
(x, y) = pjFwd pj (lon0, lat0)

-- | An inverse projection from (x, y) to (longitude, latitude):
(lon, lat) = pjInv pj (x, y)

-- | Convert our test position from one projection to another (pj0 -> pj):
(x2, y2, z2) = pjTransformPt pj0 pj (lon0, lat0, alt0)

main :: IO ()
main = do
putStrLn \$ "(x, y): " ++ (show (x, y))
putStrLn \$ "(lon, lat): " ++ (show (lon * 180 / pi, lat * 180 / pi))
putStrLn \$ "(x, y, z): " ++ (show \$ (x2, y2, z2))
return ()``````

You should see the following when you compile and run the above:

``````(x, y): (615096.1096381239,4437953.6592040695)
(lon, lat): (22.350000000000662,40.083999999999584)
(x, y, z): (615096.1096381239,4437953.6592040695,2843.0)``````
Depends on 2 packages:
Used by 1 package: