.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/example_find_positions_at_obs_times.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_gallery_example_find_positions_at_obs_times.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_example_find_positions_at_obs_times.py:


Finding the closest or interpolated positions at given times (e.g. wave observations).
=======================================================================================

.. GENERATED FROM PYTHON SOURCE LINES 5-13

.. code-block:: Python


    from pathlib import Path
    from trajan.readers.omb import read_omb_csv
    import xarray as xr
    import coloredlogs

    coloredlogs.install(level='debug')








.. GENERATED FROM PYTHON SOURCE LINES 14-15

Read the data

.. GENERATED FROM PYTHON SOURCE LINES 15-19

.. code-block:: Python

    data = Path.cwd().parent / "tests" / "test_data" / "csv" / "omb3.csv"
    ds = read_omb_csv(data)
    print(ds)





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG reading /home/runner/work/trajan/trajan/tests/test_data/csv/omb3.csv..
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG omb_dataframe at index 94 is:
    Date Time (UTC)    16/Jun/2022 18:27:19
    Device                        drifter_2
    Direction                            MO
    Payload                             NaN
    Approx Lat/Lng          74.36745,3.3274
    Payload (Text)                      NaN
    Length (Bytes)                        0
    Credits                               1
    Name: 94, dtype: object
    this is empty (Length (Bytes) is 0), drop
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG start applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG done applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG start applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG done applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG start applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.readers.omb[2121] DEBUG done applying sliding_filter_nsigma
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting time-variable for "obs"..
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: obs, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected un-structured (2D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.traj[2121] DEBUG No grid-mapping specified, checking if coordinates are lon/lat..
    2024-12-16 16:26:13 fv-az1766-447 trajan.traj[2121] DEBUG No grid-mapping specified, checking if coordinates are lon/lat..
    2024-12-16 16:26:13 fv-az1766-447 trajan.traj[2121] DEBUG No grid-mapping specified, checking if coordinates are lon/lat..
    2024-12-16 16:26:13 fv-az1766-447 trajan.traj[2121] DEBUG No grid-mapping specified, checking if coordinates are lon/lat..
    <xarray.Dataset> Size: 119kB
    Dimensions:                              (trajectory: 3,
                                              frequencies_waves_imu: 55, obs: 150,
                                              obs_waves_imu: 26)
    Coordinates:
      * trajectory                           (trajectory) <U9 108B 'drifter_1' .....
      * frequencies_waves_imu                (frequencies_waves_imu) float64 440B ...
    Dimensions without coordinates: obs, obs_waves_imu
    Data variables: (12/14)
        time                                 (trajectory, obs) datetime64[ns] 4kB ...
        lat                                  (trajectory, obs) float64 4kB 79.4 ....
        lon                                  (trajectory, obs) float64 4kB 3.031 ...
        time_waves_imu                       (trajectory, obs_waves_imu) datetime64[ns] 624B ...
        accel_energy_spectrum                (trajectory, obs_waves_imu, frequencies_waves_imu) float64 34kB ...
        elevation_energy_spectrum            (trajectory, obs_waves_imu, frequencies_waves_imu) float64 34kB ...
        ...                                   ...
        pHs0                                 (trajectory, obs_waves_imu) float64 624B ...
        pT02                                 (trajectory, obs_waves_imu) float64 624B ...
        pT24                                 (trajectory, obs_waves_imu) float64 624B ...
        Hs0                                  (trajectory, obs_waves_imu) float64 624B ...
        T02                                  (trajectory, obs_waves_imu) float64 624B ...
        T24                                  (trajectory, obs_waves_imu) float64 624B ...
    Attributes: (12/14)
        Conventions:          CF-1.10
        featureType:          trajectory
        geospatial_lat_min:   74.1878338
        geospatial_lat_max:   79.7326024
        geospatial_lon_min:   2.9766619
        geospatial_lon_max:   7.5205089
        ...                   ...
        creator_name:         XX:TODO
        creator_email:        XX:TODO
        title:                XX:TODO
        summary:              XX:TODO
        creator_institution:  XX:TODO
        history:              created with trajan.reader.omb from a Rock7 Iridium...




.. GENERATED FROM PYTHON SOURCE LINES 20-23

The wave data in the variable `pHs0` is given along a different observation dimension.
Because it is also a observation, i.e. in the style of 2D trajectory
datasets, we need to iterate over the trajectories:

.. GENERATED FROM PYTHON SOURCE LINES 23-35

.. code-block:: Python



    def gridwaves(tds):
        t = tds[['lat', 'lon',
                 'time']].traj.gridtime(tds['time_waves_imu'].squeeze())
        return t.traj.to_2d(obs_dim='obs_waves_imu')


    dsw = ds.groupby('trajectory').map(gridwaves)

    print(dsw)





.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting time-variable for "obs"..
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: obs, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected un-structured (2D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: time, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected structured (1D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting time-variable for "obs"..
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: obs, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected un-structured (2D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: time, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected structured (1D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting time-variable for "obs"..
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: obs, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected un-structured (2D) trajectory dataset
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detecting trajectory dimension
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected obs-dim: time, detected time-variable: time.
    2024-12-16 16:26:13 fv-az1766-447 trajan.accessor[2121] DEBUG Detected structured (1D) trajectory dataset
    <xarray.Dataset> Size: 2kB
    Dimensions:        (trajectory: 3, obs_waves_imu: 26)
    Coordinates:
      * obs_waves_imu  (obs_waves_imu) int64 208B 0 1 2 3 4 5 ... 20 21 22 23 24 25
      * trajectory     (trajectory) <U9 108B 'drifter_1' 'drifter_2' 'drifter_3'
    Data variables:
        lat            (trajectory, obs_waves_imu) float64 624B nan 79.38 ... nan
        lon            (trajectory, obs_waves_imu) float64 624B nan 3.101 ... nan
        time           (trajectory, obs_waves_imu) datetime64[ns] 624B 2022-06-15...
    Attributes: (12/14)
        Conventions:          CF-1.10
        featureType:          trajectory
        geospatial_lat_min:   74.1878338
        geospatial_lat_max:   79.7326024
        geospatial_lon_min:   2.9766619
        geospatial_lon_max:   7.5205089
        ...                   ...
        creator_name:         XX:TODO
        creator_email:        XX:TODO
        title:                XX:TODO
        summary:              XX:TODO
        creator_institution:  XX:TODO
        history:              created with trajan.reader.omb from a Rock7 Iridium...




.. GENERATED FROM PYTHON SOURCE LINES 36-38

We now have the positions interpolated to the IMU (wave) observations. We
could also merge these together to one dataset again:

.. GENERATED FROM PYTHON SOURCE LINES 38-44

.. code-block:: Python


    ds = xr.merge((ds, dsw.rename({
        'lon': 'lon_waves',
        'lat': 'lat_waves'
    }).drop('time')))
    print(ds)




.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    /home/runner/work/trajan/trajan/examples/example_find_positions_at_obs_times.py:42: DeprecationWarning: dropping variables using `drop` is deprecated; use drop_vars.
      }).drop('time')))
    <xarray.Dataset> Size: 121kB
    Dimensions:                              (trajectory: 3,
                                              frequencies_waves_imu: 55, obs: 150,
                                              obs_waves_imu: 26)
    Coordinates:
      * trajectory                           (trajectory) <U9 108B 'drifter_1' .....
      * frequencies_waves_imu                (frequencies_waves_imu) float64 440B ...
      * obs_waves_imu                        (obs_waves_imu) int64 208B 0 1 ... 25
    Dimensions without coordinates: obs
    Data variables: (12/16)
        time                                 (trajectory, obs) datetime64[ns] 4kB ...
        lat                                  (trajectory, obs) float64 4kB 79.4 ....
        lon                                  (trajectory, obs) float64 4kB 3.031 ...
        time_waves_imu                       (trajectory, obs_waves_imu) datetime64[ns] 624B ...
        accel_energy_spectrum                (trajectory, obs_waves_imu, frequencies_waves_imu) float64 34kB ...
        elevation_energy_spectrum            (trajectory, obs_waves_imu, frequencies_waves_imu) float64 34kB ...
        ...                                   ...
        pT24                                 (trajectory, obs_waves_imu) float64 624B ...
        Hs0                                  (trajectory, obs_waves_imu) float64 624B ...
        T02                                  (trajectory, obs_waves_imu) float64 624B ...
        T24                                  (trajectory, obs_waves_imu) float64 624B ...
        lat_waves                            (trajectory, obs_waves_imu) float64 624B ...
        lon_waves                            (trajectory, obs_waves_imu) float64 624B ...
    Attributes: (12/14)
        Conventions:          CF-1.10
        featureType:          trajectory
        geospatial_lat_min:   74.1878338
        geospatial_lat_max:   79.7326024
        geospatial_lon_min:   2.9766619
        geospatial_lon_max:   7.5205089
        ...                   ...
        creator_name:         XX:TODO
        creator_email:        XX:TODO
        title:                XX:TODO
        summary:              XX:TODO
        creator_institution:  XX:TODO
        history:              created with trajan.reader.omb from a Rock7 Iridium...





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.241 seconds)


.. _sphx_glr_download_gallery_example_find_positions_at_obs_times.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: example_find_positions_at_obs_times.ipynb <example_find_positions_at_obs_times.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: example_find_positions_at_obs_times.py <example_find_positions_at_obs_times.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: example_find_positions_at_obs_times.zip <example_find_positions_at_obs_times.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_