From bc8026a46606abf48679d81d80991623d5b91ca7 Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Mon, 9 Apr 2018 22:27:59 +0200 Subject: Add description of projection and +lat_b parameter --- docs/source/operations/projections/airy.rst | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/docs/source/operations/projections/airy.rst b/docs/source/operations/projections/airy.rst index d2730592..eefda4e9 100644 --- a/docs/source/operations/projections/airy.rst +++ b/docs/source/operations/projections/airy.rst @@ -3,6 +3,11 @@ ******************************************************************************** Airy ******************************************************************************** + +The Airy projection is an azimuthal minimum error projection for the region +within the small or great circle defined by an angular distance, +:math:`\phi_b`, from the tangency point of the plane :math:`( \lambda_0, \phi_0 )`. + +---------------------+----------------------------------------------------------+ | **Classification** | | +---------------------+----------------------------------------------------------+ @@ -14,7 +19,10 @@ Airy +---------------------+----------------------------------------------------------+ | **Options** | +---------------------+----------------------------------------------------------+ -| `+lat_b` | | +| `+lat_b` | Angular distance from tangency point of the plane | +| | :math:`( \lambda_0, \phi_0 )` where the error is kept at | +| | minimum. Defaults to :math:`90^{\circ}` which is | +| | suitable for hemispherical maps. | +---------------------+----------------------------------------------------------+ | `+no_cut` | Do not cut at hemisphere limit | +---------------------+----------------------------------------------------------+ -- cgit v1.2.3 From b7c59722cb0058391e47d2899d510961a0985c59 Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Mon, 9 Apr 2018 22:28:20 +0200 Subject: Add more test cases for airy projection --- test/gie/builtins.gie | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/test/gie/builtins.gie b/test/gie/builtins.gie index 4d744135..84d5c832 100644 --- a/test/gie/builtins.gie +++ b/test/gie/builtins.gie @@ -318,6 +318,74 @@ expect -189109.886908621 94583.752387504 accept -2 -1 expect -189109.886908621 -94583.752387504 +------------------------------------------------------------------------------- +Test north polar aspect +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lat_0=90 +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 0 0 +expect 0 -1.3863 +accept 0 90 +expect 0 0 +accept 0 -90 +expect failure errno tolerance_condition + + +------------------------------------------------------------------------------- +Test south polar aspect +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lat_0=-90 +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 0 0 +expect 0 1.3863 +accept 0 -90 +expect 0 0 +accept 0 90 +expect failure errno tolerance_condition + +------------------------------------------------------------------------------- +Test oblique aspect +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lon_0=45 +lat_0=45 +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 45 45 +expect 0 0 +accept 0 0 +expext -0.7336 -0.5187 +accept -45 -45 +expect failure errno tolerance_condition + +------------------------------------------------------------------------------- +Test that coordinates on the opposing hemisphere are projected when using ++no_cut. +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lat_0=-90 +no_cut +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 0 10 +expect 0 1.5677 + + +------------------------------------------------------------------------------- +Test the +lat_b parameter +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lat_b=89.99999999 # check tolerance +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 0 0 +expect 0 0 +------------------------------------------------------------------------------- +operation +proj=airy +R=1 +lat_b=30 +------------------------------------------------------------------------------- +tolerance 0.1 mm +accept 0 0 +expect 0 0 +accept 25 25 +expect 0.3821 0.4216 + =============================================================================== Aitoff -- cgit v1.2.3