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| author | Toby C. Wilkinson <open@tobywilkinson.co.uk> | 2021-12-20 19:22:46 +0000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-12-20 20:22:46 +0100 |
| commit | 5fe037f86a7ed040893c3406aed8bffebbb722f6 (patch) | |
| tree | e237860503c653a6f404f375deedca18949b1d81 /docs/source/operations/projections/images | |
| parent | dad309d7fca5479ce936f320911df2221a78e43c (diff) | |
| download | PROJ-5fe037f86a7ed040893c3406aed8bffebbb722f6.tar.gz PROJ-5fe037f86a7ed040893c3406aed8bffebbb722f6.zip | |
Fix and additional options for Peirce Quincuncial projections (#2978)
This fixes the current forward implementation of Peirce Quincuncial proj to correctly flip/reflect out the southern hemisphere to four triangles, and rotate entire result to a square or diamond. (It there resolves the issues identified with pull request https://github.com/OSGeo/PROJ/pull/2230 , where southern hemisphere was wrongly projected over northern, and reverses the restriction to northern hemisphere introduced there). It also adds additional lateral projection of the hemispheres.
- This PR adds an optional parameter `+type` which allows selection of projection. The `+type=square` and `+type=diamond` types match in principle ESRI's twin implementations of square and diamond PQ projs. The **default** if not specified is `+type=diamond`.
- The previous behaviour restricted to the northern hemisphere can be reproduced using the `+type=nhemisphere`, though this is an edge case only.
- An additional `+type=horizontal` and `+type=vertical` rectangular lateral versions have been added that place each hemisphere side-by-side. This is primarily to allow creation of projections such as Greiger Triptychial, which also require the additional optional params `scrollx` or `scrolly` in order to shift parts of the projection from one side of the map to the other.
- Additional documentation has been added to proj description, including quoting the usual meridian used in common usage of projection, and images showing the different types.
Diffstat (limited to 'docs/source/operations/projections/images')
| -rw-r--r-- | docs/source/operations/projections/images/grieger_triptychial.png | bin | 0 -> 603219 bytes |
| -rw-r--r-- | docs/source/operations/projections/images/peirce_q.png | bin | 375467 -> 0 bytes |
| -rw-r--r-- | docs/source/operations/projections/images/peirce_q_diamond.png | bin | 0 -> 394555 bytes |
| -rw-r--r-- | docs/source/operations/projections/images/peirce_q_horizontal.png | bin | 0 -> 568102 bytes |
| -rw-r--r-- | docs/source/operations/projections/images/peirce_q_square.png | bin | 0 -> 587992 bytes |
5 files changed, 0 insertions, 0 deletions
diff --git a/docs/source/operations/projections/images/grieger_triptychial.png b/docs/source/operations/projections/images/grieger_triptychial.png Binary files differnew file mode 100644 index 00000000..2e03a67b --- /dev/null +++ b/docs/source/operations/projections/images/grieger_triptychial.png diff --git a/docs/source/operations/projections/images/peirce_q.png b/docs/source/operations/projections/images/peirce_q.png Binary files differdeleted file mode 100644 index 646e4f80..00000000 --- a/docs/source/operations/projections/images/peirce_q.png +++ /dev/null diff --git a/docs/source/operations/projections/images/peirce_q_diamond.png b/docs/source/operations/projections/images/peirce_q_diamond.png Binary files differnew file mode 100644 index 00000000..b8a84967 --- /dev/null +++ b/docs/source/operations/projections/images/peirce_q_diamond.png diff --git a/docs/source/operations/projections/images/peirce_q_horizontal.png b/docs/source/operations/projections/images/peirce_q_horizontal.png Binary files differnew file mode 100644 index 00000000..615c2abf --- /dev/null +++ b/docs/source/operations/projections/images/peirce_q_horizontal.png diff --git a/docs/source/operations/projections/images/peirce_q_square.png b/docs/source/operations/projections/images/peirce_q_square.png Binary files differnew file mode 100644 index 00000000..485b23a1 --- /dev/null +++ b/docs/source/operations/projections/images/peirce_q_square.png |
