From ed462b39fb7d9b92a75a069da707f2b7921b2820 Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Mon, 21 Jan 2019 19:31:02 +0100 Subject: proj_create_crs_to_crs(): defer selection of actual coordinate operation until proj_trans() is called (fixes #1229) --- docs/source/apps/cs2cs.rst | 4 ++++ docs/source/development/reference/functions.rst | 9 +++++++++ 2 files changed, 13 insertions(+) (limited to 'docs/source') diff --git a/docs/source/apps/cs2cs.rst b/docs/source/apps/cs2cs.rst index 8df67d72..967add36 100644 --- a/docs/source/apps/cs2cs.rst +++ b/docs/source/apps/cs2cs.rst @@ -154,6 +154,10 @@ When using a WKT definition or a AUTHORITY:CODE, the axis order of the CRS will be enforced. So for example if using EPSG:4326, the first value expected (or returned) will be a latitude. +Internally, :program:`cs2cs` uses the :c:func:`proj_create_crs_to_crs` function +to compute the appropriate coordinate operation, so implementation details of +this function directly impact the results returned by the program. + The environment parameter :envvar:`PROJ_LIB` establishes the directory for resource files (database, datum shift grids, etc.) diff --git a/docs/source/development/reference/functions.rst b/docs/source/development/reference/functions.rst index 87271117..4052ff82 100644 --- a/docs/source/development/reference/functions.rst +++ b/docs/source/development/reference/functions.rst @@ -108,11 +108,20 @@ paragraph for more details. When using that syntax, the axis order and unit for geographic CRS will be longitude, latitude, and the unit degrees. + - the name of a CRS as found in the PROJ database, e.g "WGS84", "NAD27", etc. + - more generally any string accepted by :c:func:`proj_create` An "area of use" can be specified in area. When it is supplied, the more accurate transformation between two given systems can be chosen. + When no area of use is specific and several coordinate operations are possible + depending on the area of use, this function will internally store those + candidate coordinate operations in the return PJ object. Each subsequent + coordinate transformation done with :c:func:`proj_trans` will then select + the appropriate coordinate operation by comparing the input coordinates with + the area of use of the candidate coordinate operations. + Example call: .. code-block:: C -- cgit v1.2.3 From 0b75ef6ae8f61fe9b518e96f9083449e7e2e8971 Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Mon, 21 Jan 2019 19:38:22 +0100 Subject: Update cs2cs man page result (the change is due to ntv1_can.dat being used instead of conus...) (refs #1229) --- docs/source/apps/cs2cs.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'docs/source') diff --git a/docs/source/apps/cs2cs.rst b/docs/source/apps/cs2cs.rst index 967add36..579dc65e 100644 --- a/docs/source/apps/cs2cs.rst +++ b/docs/source/apps/cs2cs.rst @@ -199,7 +199,7 @@ The x-y output data will appear as three lines of: :: - 1402285.98 5076292.42 -0.00 + 1402293.44 5076292.68 0.00 Using EPSG codes -- cgit v1.2.3