.. _example_37:

(37) Spectral coherence between gravity and bathymetry grids
------------------------------------------------------------

The next script produces the plot in Figure.
We demonstrate how :doc:`grdfft </grdfft>` is used to compute the
spectral coherence between two data sets, here multibeam bathymetry
and satellite-derived gravity.  The grids are detrended and tapered
before the Fourier transform is computed; the intermediate plots show
the grids being extended and padded to a suitable dimension.

.. literalinclude:: /_verbatim/example_37.txt
   :language: bash

.. figure:: /_images/example_37.*
   :width: 500 px
   :align: center

   Spectral coherence between gravity and bathymetry grids.