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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/source/operations/pipeline.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/docs/source/operations/pipeline.rst b/docs/source/operations/pipeline.rst index 33112536..90112c05 100644 --- a/docs/source/operations/pipeline.rst +++ b/docs/source/operations/pipeline.rst @@ -128,3 +128,34 @@ Optional .. option:: +inv Invert a step in a pipeline. + +.. option:: +omit_fwd + + .. versionadded:: 6.3.0 + + Skip a step of the pipeline when it is followed in the forward path. + + The following example shows a combined use of :ref:`push <push>` and :ref:`pop <pop>` operators, + with ``omit_fwd`` and ``omit_inv`` options, to implement a vertical adjustment that must + be done in a interpolation CRS that is different from the horizontal CRS + used in input and output. +omit_fwd in the forward path avoid a useless + inverse horizontal transformation and relies on the pop operator to restore + initial horizontal coordinates. +omit_inv serves the similar purpose when + the pipeline is executed in the reverse direction + + :: + + +proj=pipeline + +step +proj=unitconvert +xy_in=deg +xy_out=rad + +step +proj=push +v_1 +v_2 + +step +proj=hgridshift +grids=nvhpgn.gsb +omit_inv + +step +proj=vgridshift +grids=g1999u05.gtx +multiplier=1 + +step +inv +proj=hgridshift +grids=nvhpgn.gsb +omit_fwd + +step +proj=pop +v_1 +v_2 + +step +proj=unitconvert +xy_in=rad +xy_out=deg + +.. option:: +omit_inv + + .. versionadded:: 6.3.0 + + Skip a step of the pipeline when it is followed in the reverse path. |