From c635dcc671810f46cf4c2783da7d11b6cd0b97ec Mon Sep 17 00:00:00 2001 From: Daniel Schadt Date: Sat, 13 May 2023 16:59:13 +0200 Subject: add docs for fix elevation jump transformer --- doc/user/images/fixed_elevation_jump.png | Bin 0 -> 61739 bytes doc/user/images/wrong_elevation_jump.png | Bin 0 -> 39593 bytes doc/user/transformers.rst | 29 +++++++++++++++++++++++++++++ 3 files changed, 29 insertions(+) create mode 100644 doc/user/images/fixed_elevation_jump.png create mode 100644 doc/user/images/wrong_elevation_jump.png diff --git a/doc/user/images/fixed_elevation_jump.png b/doc/user/images/fixed_elevation_jump.png new file mode 100644 index 0000000..4d1334a Binary files /dev/null and b/doc/user/images/fixed_elevation_jump.png differ diff --git a/doc/user/images/wrong_elevation_jump.png b/doc/user/images/wrong_elevation_jump.png new file mode 100644 index 0000000..03d454d Binary files /dev/null and b/doc/user/images/wrong_elevation_jump.png differ diff --git a/doc/user/transformers.rst b/doc/user/transformers.rst index d053052..7ce4bc7 100644 --- a/doc/user/transformers.rst +++ b/doc/user/transformers.rst @@ -19,6 +19,11 @@ In other applications, transformers are sometimes called "filters". That term however has many different meanings (like the filters on the "Browse" page), and as such, Fietsboek calls them transformers. +Keep in mind that the transformers provide a "quick and convenient" way to +apply a predefined set of changes to a track. If you need to do fine-grained +edits to a GPX file, you need to use a different tool and edit the file before +uploading it to Fietsboek. + Fix Null Elevation ------------------ @@ -44,6 +49,30 @@ point. To fix those points, the transformer will find the first correct point, and copy its elevation to the wrong points. +Fix Elevation Jumps +------------------- + +The *fix elevation jumps* transformer eliminates big elevation jumps in the +middle of a track. This is useful to deal with "stitched" GPX files, where the +elevation is consistent within a single track, but the absolute value might not +be correct (e.g. if the device recalibrates): + +.. image:: images/wrong_elevation_jump.png + :width: 600 + :alt: The elevation profile having a big jump in the middle. + +In this track, the device was re-calibrated mid-track. The transformer will +adjust the elevation values: + +.. image:: images/fixed_elevation_jump.png + :width: 600 + :alt: The same elevation profile with the jump removed. + +The detection of jumps work similarly to the *fix null elevation* transformer, +with the difference that it works in the middle of tracks. It will consider the +earlier points as anchor, and then adjust the later points such that the first +point after the jump has the same elevation as the last point before the jump. + Remove Breaks ------------- -- cgit v1.2.3