Automatically convert xlim/ylim to Web Mercator when tiles=True

doc/ref/plotting_options/axis.ipynb

@@ -881,7 +881,9 @@
     "(option-xlim_ylim)=\n",
     "## `xlim / ylim`\n",
     "\n",
-    "The x- and y-axis ranges can be defined with the `xlim` and `ylim` options, respectively. These options accept a 2-tuple representing the minimum and maximum bounds of the plotted ranged. One bound can be left unset by using `None` (e.g. `xlim=(10, None)` means there is no upper bound)."
+    "The x- and y-axis ranges can be defined with the `xlim` and `ylim` options, respectively. These options accept a 2-tuple representing the minimum and maximum bounds of the plotted ranged. One bound can be left unset by using `None` (e.g. `xlim=(10, None)` means there is no upper bound).\n",
+    "\n",
+    "If [`tiles`](option-tiles) is provided and the `xlim` and `ylim` are in `lat`/`lon` coordinates, they will be automatically transformed to Web Mercator coordinates."
    ]
   },
   {

doc/ref/plotting_options/geographic.ipynb

@@ -425,6 +425,37 @@
     "layout.cols(2)"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "dcc48e78",
+   "metadata": {},
+   "source": [
+    "If `xlim` and `ylim` are in `lat`/`lon` coordinates, they will be automatically transformed to Web Mercator coordinates."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "0f86e368",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import holoviews as hv\n",
+    "import hvplot.pandas  # noqa\n",
+    "import xyzservices.providers as xyz\n",
+    "\n",
+    "df = hvplot.sampledata.earthquakes(\"pandas\")\n",
+    "\n",
+    "plot_opts = dict(x='lon', y='lat', alpha=0.2, c='brown', frame_width=250, xlim=(-130, -70), ylim=(30, 60))\n",
+    "layout = (\n",
+    "    df.hvplot.points(tiles=True, title=\"Default: OpenStreetMap\", **plot_opts) +\n",
+    "    df.hvplot.points(tiles=xyz.Esri.WorldPhysical, title=\"xyz.Esri.WorldPhysical\", **plot_opts) +\n",
+    "    df.hvplot.points(tiles='EsriTerrain', title=\"EsriTerrain string\", **plot_opts) +\n",
+    "    df.hvplot.points(tiles=hv.element.tiles.EsriImagery, title=\"HoloViews Tiles\", **plot_opts)\n",
+    ")\n",
+    "layout.cols(2)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "d0db0527-bb56-4e99-8864-22819b6367c3",

hvplot/converter.py

@@ -47,7 +47,7 @@
 from holoviews.plotting.util import process_cmap
 from holoviews.operation import histogram, apply_when
 from holoviews.streams import Buffer, Pipe
-from holoviews.util.transform import dim, lon_lat_to_easting_northing
+from holoviews.util.transform import dim
 from pandas import DatetimeIndex, MultiIndex
 
 from .backend_transforms import _transfer_opts_cur_backend
@@ -82,6 +82,9 @@
     import_geoviews,
     is_mpl_cmap,
     _find_stack_level,
+    is_within_latlon_bounds,
+    convert_latlon_to_mercator,
+    convert_limit_to_mercator,
 )
 from .utilities import hvplot_extension
 
@@ -1003,6 +1006,17 @@ def __init__(
         elif projection is False:
             # to disable automatic projection of tiles
             self.output_projection = projection
+        elif tiles and not self.geo and (xlim or ylim):
+            should_convert = (
+                not is_geodataframe(data)
+                and x is not None
+                and y is not None
+                and is_within_latlon_bounds(data, x, y)
+            )
+
+            if should_convert:
+                xlim = convert_limit_to_mercator(xlim, is_x_axis=True)
+                ylim = convert_limit_to_mercator(ylim, is_x_axis=False)
 
         # Operations
         if resample_when is not None and not any([rasterize, datashade, downsample]):
@@ -2529,26 +2543,16 @@ def _process_tiles_without_geo(self, data, x, y):
         elif is_geodataframe(data):
             if getattr(data, 'crs', None) is not None:
                 data = data.to_crs(epsg=3857)
-        else:
-            min_x = np.min(data[x])
-            max_x = np.max(data[x])
-            min_y = np.min(data[y])
-            max_y = np.max(data[y])
-
-            x_within_bounds = -180 <= min_x <= 360 and -180 <= max_x <= 360
-            y_within_bounds = -90 <= min_y <= 90 and -90 <= max_y <= 90
-            if x_within_bounds and y_within_bounds:
-                data = data.copy()
-                lons_180 = (data[x] + 180) % 360 - 180  # ticks are better with -180 to 180
-                easting, northing = lon_lat_to_easting_northing(lons_180, data[y])
-                new_x = 'x' if 'x' not in data else 'x_'  # quick existing var check
-                new_y = 'y' if 'y' not in data else 'y_'
-                data[new_x] = easting
-                data[new_y] = northing
-                if is_xarray(data):
-                    data = data.swap_dims({x: new_x, y: new_y})
-                x = new_x
-                y = new_y
+        elif is_within_latlon_bounds(data, x, y):
+            data = data.copy()
+            easting, northing = convert_latlon_to_mercator(data[x], data[y])
+            new_x = 'x' if 'x' not in data else 'x_'
+            new_y = 'y' if 'y' not in data else 'y_'
+            data[new_x] = easting
+            data[new_y] = northing
+            if is_xarray(data):
+                data = data.swap_dims({x: new_x, y: new_y})
+            x, y = new_x, new_y
         return data, x, y
 
     def chart(self, element, x, y, data=None):

hvplot/tests/testgeowithoutgv.py

@@ -9,6 +9,7 @@
 import pytest
 
 from hvplot.util import is_geodataframe
+from holoviews.util.transform import lon_lat_to_easting_northing
 
 try:
     import dask.dataframe as dd
@@ -30,6 +31,29 @@ def simple_df():
     return pd.DataFrame(np.random.rand(10, 2), columns=['x', 'y'])
 
 
+@pytest.fixture
+def lat_lon_df():
+    return pd.DataFrame(
+        {
+            'lon': [-120.0, -100.0, -80.0],
+            'lat': [30.0, 35.0, 40.0],
+        }
+    )
+
+
+@pytest.fixture
+def mercator_df():
+    x_merc, y_merc = lon_lat_to_easting_northing(
+        np.array([-120.0, -100.0, -80.0]), np.array([30.0, 35.0, 40.0])
+    )
+    return pd.DataFrame(
+        {
+            'x': x_merc,
+            'y': y_merc,
+        }
+    )
+
+
 class TestAnnotationNotGeo:
     def test_plot_tiles_doesnt_set_geo(self, simple_df):
         plot = simple_df.hvplot.points('x', 'y', tiles=True)
@@ -104,3 +128,84 @@ def test_plot_without_crs(self):
         assert isinstance(plot.get(1), hv.Polygons)
         bk_plot = bk_renderer.get_plot(plot)
         assert bk_plot.projection == 'mercator'  # projection enabled due to `tiles=True`
+
+    def test_xlim_ylim_conversion_with_tiles(self, simple_df):
+        """Test that xlim and ylim are automatically converted to Web Mercator when tiles=True"""
+        df = pd.DataFrame(
+            {'lon': [-120.0, -100.0, -80.0], 'lat': [30.0, 35.0, 40.0], 'value': [1, 2, 3]}
+        )
+        plot = df.hvplot.points('lon', 'lat', tiles=True, xlim=(-130, -70), ylim=(25, 45))
+        points = plot.get(1)
+
+        assert 'x' in points.data.columns
+        assert 'y' in points.data.columns
+
+        xlim_expected_0, _ = lon_lat_to_easting_northing(-130, 0)
+        xlim_expected_1, _ = lon_lat_to_easting_northing(-70, 0)
+        _, ylim_expected_0 = lon_lat_to_easting_northing(0, 25)
+        _, ylim_expected_1 = lon_lat_to_easting_northing(0, 45)
+
+        bk_plot = bk_renderer.get_plot(plot)
+        x_range_start = bk_plot.handles['plot'].x_range.start
+        x_range_end = bk_plot.handles['plot'].x_range.end
+        y_range_start = bk_plot.handles['plot'].y_range.start
+        y_range_end = bk_plot.handles['plot'].y_range.end
+        assert x_range_start == xlim_expected_0
+        assert x_range_end == xlim_expected_1
+        assert y_range_start == ylim_expected_0
+        assert y_range_end == ylim_expected_1
+
+    def test_xlim_only_conversion_with_tiles(self, lat_lon_df):
+        """xlim should convert even when ylim is not provided."""
+
+        plot = lat_lon_df.hvplot.points('lon', 'lat', tiles=True, xlim=(-130, -70))
+        bk_plot = bk_renderer.get_plot(plot)
+
+        x_start = bk_plot.state.x_range.start
+        x_end = bk_plot.state.x_range.end
+
+        np.testing.assert_almost_equal(x_start, -14471533.803125564)
+        np.testing.assert_almost_equal(x_end, -7792364.355529151)
+        assert x_start < x_end
+
+    def test_ylim_only_conversion_with_tiles(self, lat_lon_df):
+        """ylim should convert even when xlim is not provided."""
+        plot = lat_lon_df.hvplot.points('lon', 'lat', tiles=True, ylim=(25, 45))
+        bk_plot = bk_renderer.get_plot(plot)
+
+        y_start = bk_plot.state.y_range.start
+        y_end = bk_plot.state.y_range.end
+
+        assert y_start > 2_000_000
+        assert y_end > 5_000_000
+        assert y_start < y_end
+
+    def test_xlim_ylim_not_converted_without_tiles(self, lat_lon_df):
+        """Test that xlim and ylim are NOT converted when tiles=False"""
+        plot = lat_lon_df.hvplot.points('lon', 'lat', xlim=(-130, -70), ylim=(25, 45))
+        bk_plot = bk_renderer.get_plot(plot)
+
+        x_range_start = bk_plot.handles['plot'].x_range.start
+        x_range_end = bk_plot.handles['plot'].x_range.end
+        y_range_start = bk_plot.handles['plot'].y_range.start
+        y_range_end = bk_plot.handles['plot'].y_range.end
+
+        assert x_range_start == -130
+        assert x_range_end == -70
+        assert y_range_start == 25
+        assert y_range_end == 45
+
+    def test_xlim_ylim_out_of_bounds_not_converted(self, mercator_df):
+        """Test that xlim and ylim are NOT converted when values are outside lat/lon bounds"""
+        plot = mercator_df.hvplot.points('x', 'y', tiles=True, xlim=(1000, 3000), ylim=(400, 800))
+        bk_plot = bk_renderer.get_plot(plot.get(1))
+
+        x_range_start = bk_plot.handles['plot'].x_range.start
+        x_range_end = bk_plot.handles['plot'].x_range.end
+        y_range_start = bk_plot.handles['plot'].y_range.start
+        y_range_end = bk_plot.handles['plot'].y_range.end
+
+        assert x_range_start == 1000
+        assert x_range_end == 3000
+        assert y_range_start == 400
+        assert y_range_end == 800