Deprecate the sample datasets (#277)

Sample data will be removed in Verde 2.0.0 in favour of using 
the Ensaio library instead. Add a deprecation warning to all
fetching and plotting functions and warnings to the documentation
and docstrings.

Co-authored-by: Leonardo Uieda <leouieda@gmail.com>

data/examples/README.txt

@@ -6,6 +6,13 @@ Sample Data
 Verde provides some sample data and ways of generating synthetic data through
 the :mod:`verde.datasets` module.
 
+.. warning::
+
+    All sample datasets in Verde are deprecated and will be
+    **removed in Verde v2.0.0**.
+    The tutorials/examples will transition to using
+    `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
 Where are my data files?
 ------------------------
 

data/examples/baja_bathymetry.py

@@ -5,8 +5,15 @@
 # This code is part of the Fatiando a Terra project (https://www.fatiando.org)
 #
 """
-Bathymetry data from Baja California
-====================================
+[DEPRECATED] Bathymetry data from Baja California
+=================================================
+
+.. warning::
+
+    All sample datasets in Verde are deprecated and will be
+    **removed in Verde v2.0.0**.
+    The tutorials/examples will transition to using
+    `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
 We provide sample bathymetry data from Baja California to test the gridding
 methods. This is the ``@tut_ship.xyz`` sample data provided by `GMT

data/examples/california_gps.py

@@ -5,8 +5,15 @@
 # This code is part of the Fatiando a Terra project (https://www.fatiando.org)
 #
 """
-GPS velocities from California
-==============================
+[DEPRECATED] GPS velocities from California
+===========================================
+
+.. warning::
+
+    All sample datasets in Verde are deprecated and will be
+    **removed in Verde v2.0.0**.
+    The tutorials/examples will transition to using
+    `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
 We provide sample 3-component GPS velocity data from the West coast of the U.S.
 The data were cut from EarthScope Plate Boundary Observatory data provided by

data/examples/rio_magnetic.py

@@ -10,10 +10,10 @@
 
 .. warning::
 
-    **The Rio magnetic anomaly dataset is deprecated and will be removed in
-    Verde v2.0.0** (functions :func:`verde.datasets.fetch_rio_magnetic` and
-    :func:`verde.datasets.setup_rio_magnetic_map`). Please use another dataset
-    instead.
+    All sample datasets in Verde are deprecated and will be
+    **removed in Verde v2.0.0**.
+    The tutorials/examples will transition to using
+    `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
 We provide sample total-field magnetic anomaly data from an airborne survey of
 Rio de Janeiro, Brazil, from the 1970s. The data are made available by the

data/examples/texas-wind.py

@@ -5,8 +5,15 @@
 # This code is part of the Fatiando a Terra project (https://www.fatiando.org)
 #
 """
-Wind speed data from Texas
-==========================
+[DEPRECATED] Wind speed data from Texas
+=======================================
+
+.. warning::
+
+    All sample datasets in Verde are deprecated and will be
+    **removed in Verde v2.0.0**.
+    The tutorials/examples will transition to using
+    `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
 This is average wind speed and air temperature for data for the state of Texas,
 USA, on February 26 2018. The original data was downloaded from `Iowa State

verde/datasets/sample_data.py

@@ -33,6 +33,15 @@
     REGISTRY.load_registry(registry_file)
 
 
+def _datasets_deprecation_warning():
+    warnings.warn(
+        "All sample datasets in Verde are deprecated and will be "
+        "removed in Verde v2.0.0. The tutorials/examples will transition "
+        "to using Ensaio (https://www.fatiando.org/ensaio/) instead.",
+        DeprecationWarning,
+    )
+
+
 def locate():
     r"""
     The absolute path to the sample data storage location on disk.
@@ -79,6 +88,13 @@ def fetch_baja_bathymetry():
     """
     Fetch sample bathymetry data from Baja California.
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     This is the ``@tut_ship.xyz`` sample data from the `GMT
     <http://gmt.soest.hawaii.edu/>`__ tutorial.
 
@@ -96,6 +112,7 @@ def fetch_baja_bathymetry():
     setup_baja_bathymetry_map: Utility function to help setup a Cartopy map.
 
     """
+    _datasets_deprecation_warning()
     data_file = REGISTRY.fetch("baja-bathymetry.csv.xz")
     data = pd.read_csv(data_file, compression="xz")
     return data
@@ -107,6 +124,13 @@ def setup_baja_bathymetry_map(
     """
     Setup a Cartopy map for the Baja California bathymetry dataset.
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     Parameters
     ----------
     ax : matplotlib Axes
@@ -145,10 +169,10 @@ def fetch_rio_magnetic():
 
     .. warning::
 
-        **The Rio magnetic anomaly dataset is deprecated and will be removed in
-        Verde v2.0.0** (functions :func:`verde.datasets.fetch_rio_magnetic` and
-        :func:`verde.datasets.setup_rio_magnetic_map`). Please use another
-        dataset instead.
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
     These data were cropped from the northwestern part of an airborne survey of
     Rio de Janeiro, Brazil, conducted in 1978. The data are made available by
@@ -198,10 +222,10 @@ def setup_rio_magnetic_map(ax, region=(-42.6, -42, -22.5, -22)):
 
     .. warning::
 
-        **The Rio magnetic anomaly dataset is deprecated and will be removed in
-        Verde v2.0.0** (functions :func:`verde.datasets.fetch_rio_magnetic` and
-        :func:`verde.datasets.setup_rio_magnetic_map`). Please use another
-        dataset instead.
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
 
     Parameters
     ----------
@@ -233,6 +257,13 @@ def fetch_california_gps():
     """
     Fetch sample GPS velocity data from California (the U.S. West coast).
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     Velocities and their standard deviations are in meters/year. Height is
     geometric height above WGS84 in meters. Velocities are referenced to the
     North American tectonic plate (NAM08). The average velocities were released
@@ -260,6 +291,7 @@ def fetch_california_gps():
     setup_california_gps_map: Utility function to help setup a Cartopy map.
 
     """
+    _datasets_deprecation_warning()
     data_file = REGISTRY.fetch("california-gps.csv.xz")
     data = pd.read_csv(data_file, compression="xz")
     return data
@@ -271,6 +303,13 @@ def setup_california_gps_map(
     """
     Setup a Cartopy map for the California GPS velocity dataset.
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     Parameters
     ----------
     ax : matplotlib Axes
@@ -307,6 +346,13 @@ def fetch_texas_wind():
     """
     Fetch sample wind speed and air temperature data for Texas, USA.
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     Data are average wind speed and air temperature for data for February 26
     2018. The original data was downloaded from `Iowa State University
     <https://mesonet.agron.iastate.edu/request/download.phtml>`__.
@@ -326,6 +372,7 @@ def fetch_texas_wind():
     setup_texas_wind_map: Utility function to help setup a Cartopy map.
 
     """
+    _datasets_deprecation_warning()
     data_file = REGISTRY.fetch("texas-wind.csv")
     data = pd.read_csv(data_file)
     return data
@@ -335,6 +382,13 @@ def setup_texas_wind_map(ax, region=(-107, -93, 25.5, 37), coastlines=True, **kw
     """
     Setup a Cartopy map for the Texas wind speed and air temperature dataset.
 
+    .. warning::
+
+        All sample datasets in Verde are deprecated and will be
+        **removed in Verde v2.0.0**.
+        The tutorials/examples will transition to using
+        `Ensaio <https://www.fatiando.org/ensaio/>`__ instead.
+
     Parameters
     ----------
     ax : matplotlib Axes