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

.. only:: html

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

        Click :ref:`here <sphx_glr_download_gallery_transformations_upward_continuation.py>`
        to download the full example code

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

.. _sphx_glr_gallery_transformations_upward_continuation.py:


Upward continuation of a regular grid
=====================================

.. GENERATED FROM PYTHON SOURCE LINES 11-70



.. image-sg:: /gallery/transformations/images/sphx_glr_upward_continuation_001.png
   :alt: upward continuation
   :srcset: /gallery/transformations/images/sphx_glr_upward_continuation_001.png
   :class: sphx-glr-single-img


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

 Out:

 .. code-block:: none


    Upward continued magnetic grid:
     <xarray.DataArray (northing: 370, easting: 346)>
    array([[  1.5318864 ,   1.85100319,   2.13679603, ..., -33.60489015,
            -31.65890937, -29.67750194],
           [  1.82033329,   2.17484726,   2.49236703, ..., -35.96395426,
            -33.83598794, -31.6667934 ],
           [  2.07317532,   2.45927687,   2.80499305, ..., -38.27995984,
            -35.97492132, -33.62307385],
           ...,
           [ 50.44856723,  53.84378576,  57.13892691, ...,   4.05301916,
              2.81272894,   1.764435  ],
           [ 47.56514008,  50.69951642,  53.74614319, ...,   4.66844263,
              3.44420588,   2.39520989],
           [ 44.6368305 ,  47.50470955,  50.29752195, ...,   5.03756138,
              3.86192233,   2.84250804]])
    Coordinates:
      * northing  (northing) float64 7.576e+06 7.576e+06 ... 7.595e+06 7.595e+06
      * easting   (easting) float64 4.655e+05 4.656e+05 ... 4.827e+05 4.828e+05
    <IPython.core.display.Image object>






|

.. code-block:: default

    import ensaio
    import pygmt
    import xarray as xr
    import xrft

    import harmonica as hm

    # Fetch magnetic grid over the Lightning Creek Sill Complex, Australia using
    # Ensaio and load it with Xarray
    fname = ensaio.fetch_lightning_creek_magnetic(version=1)
    magnetic_grid = xr.load_dataarray(fname)

    # Pad the grid to increase accuracy of the FFT filter
    pad_width = {
        "easting": magnetic_grid.easting.size // 3,
        "northing": magnetic_grid.northing.size // 3,
    }
    # drop the extra height coordinate
    magnetic_grid_no_height = magnetic_grid.drop_vars("height")
    magnetic_grid_padded = xrft.pad(magnetic_grid_no_height, pad_width)

    # Upward continue the magnetic grid, from 500 m to 1000 m
    # (a height displacement of 500m)
    upward_continued = hm.upward_continuation(magnetic_grid_padded, height_displacement=500)

    # Unpad the upward continued grid
    upward_continued = xrft.unpad(upward_continued, pad_width)

    # Show the upward continued grid
    print("\nUpward continued magnetic grid:\n", upward_continued)


    # Plot original magnetic anomaly and the upward continued grid
    fig = pygmt.Figure()
    with fig.subplot(nrows=1, ncols=2, figsize=("28c", "15c"), sharey="l"):
        # Make colormap for both plots data
        scale = 2500
        pygmt.makecpt(cmap="polar+h", series=[-scale, scale], background=True)
        with fig.set_panel(panel=0):
            # Plot magnetic anomaly grid
            fig.grdimage(
                grid=magnetic_grid,
                projection="X?",
                cmap=True,
            )
            # Add colorbar
            fig.colorbar(
                frame='af+l"Magnetic anomaly at 500m [nT]"',
                position="JBC+h+o0/1c+e",
            )
        with fig.set_panel(panel=1):
            # Plot upward continued grid
            fig.grdimage(grid=upward_continued, projection="X?", cmap=True)
            # Add colorbar
            fig.colorbar(
                frame='af+l"Upward continued to 1000m [nT]"',
                position="JBC+h+o0/1c+e",
            )
    fig.show()


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

   **Total running time of the script:** ( 0 minutes  2.616 seconds)


.. _sphx_glr_download_gallery_transformations_upward_continuation.py:


.. only :: html

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



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

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



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

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


.. only:: html

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

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