.. _sec-plot_contours:

plot.plot_contours 
==================

``plot_contours(grid, fig=None, projection="M15c", dtype=None)``

Plots contours of a given grid object.

Arguments:
----------
    - **grid** (*xarray.DataArray*): grid object to plot contours of
    - **fig** (*pygmt.Figure, optional*): figure object to add contours to. Defaults to None.
    - **projection** (*str, optional*): pygmt projection. Defaults to 'M15c'.
    - **dtype** (*str, optional*): data type for contours. Defaults to None.

Returns:
--------
    *None*

Example 
-------

.. code-block:: python

    import plot
    import pygmt
    # load in the synthetic test model as a slab_model instance
    model = plot.slab_model("../output/exp_slab2_04-18","surface") # synthetic test slab made with the 04-18 database
    # initialize figure as pygmt.Figure
    fig = pygmt.Figure()
    # making a plot of the model depth
    plot.plot(
        model.dep_grid, # specifies which grid object to plot
        fig=fig, # add this plot to the existing figure
        basemap=True, # add basemap to the plot
        nan_transparent=True, # removing nan values to make basemap visible
        title="exp slab model with 04-18 database", # adding a title to the plot
        dtype="depth", # specifying the datatype for labeling the colorbar
        region=model.region, # specifying the region boundaries to use
        show=False, # do not display the figure 
    )
    # overlaying the model uncertainty using contours
    plot.plot_contours(
        model.unc_grid, # specify the uncertainty grid
        fig=fig, # add this plot to the existing figure
        dtype="Depth Uncertainty (km)" # specify the data type for labeling the colorbar
    )
    # save the figure to jpeg file
    fig.savefig("output/exp_slab2_04-18_depth_with_unc.jpg")
    # display the figure
    fig.show()

.. _plot_example_figure:
.. figure:: figures/exp_slab2_04-18_depth.jpg

    Output of example shown above