From 9bd3ca63d42ea89e03e93563b67344211e6472de Mon Sep 17 00:00:00 2001 From: Leo Singer Date: Thu, 18 Aug 2011 02:17:30 -0700 Subject: [PATCH] Defined the inverse transform for Mollweide projection --- lib/matplotlib/projections/geo.py | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/matplotlib/projections/geo.py b/lib/matplotlib/projections/geo.py index 8a20f5c..9d24e96 100644 --- a/lib/matplotlib/projections/geo.py +++ b/lib/matplotlib/projections/geo.py @@ -481,8 +481,15 @@ class MollweideAxes(GeoAxes): self._resolution = resolution def transform(self, xy): - # MGDTODO: Math is hard ;( - return xy + x = xy[:, 0:1] + y = xy[:, 1:2] + + sqrt2 = np.sqrt(2) + sintheta = y / sqrt2 + costheta = np.sqrt(1. - 0.5 * y * y) + longitude = 0.25 * sqrt2 * np.pi * x / costheta + latitude = np.arcsin(2 / np.pi * (np.arcsin(sintheta) + sintheta * costheta)) + return np.concatenate((longitude, latitude), 1) transform.__doc__ = Transform.transform.__doc__ def inverted(self): -- 1.7.5