feat: (Series|DataFrame).plot.(line|area|scatter) (#431)

Fixing internal bugs:
line: b/322177942
scatter: b/322178336
area: b/322178394

Author: chelsea-lin

Diff for: bigframes/operations/_matplotlib/__init__.py

@@ -17,6 +17,9 @@
 
 PLOT_CLASSES: dict[str, type[core.MPLPlot]] = {
     "hist": hist.HistPlot,
+    "line": core.LinePlot,
+    "area": core.AreaPlot,
+    "scatter": core.ScatterPlot,
 }
 
 

Diff for: bigframes/operations/_matplotlib/core.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import abc
+import typing
 
 import matplotlib.pyplot as plt
 
@@ -28,3 +29,44 @@ def draw(self) -> None:
     @property
     def result(self):
         return self.axes
+
+
+class SamplingPlot(MPLPlot):
+    @abc.abstractproperty
+    def _kind(self):
+        pass
+
+    def __init__(self, data, **kwargs) -> None:
+        self.kwargs = kwargs
+        self.data = self._compute_plot_data(data)
+
+    def generate(self) -> None:
+        self.axes = self.data.plot(kind=self._kind, **self.kwargs)
+
+    def _compute_plot_data(self, data):
+        # TODO: Cache the sampling data in the PlotAccessor.
+        sampling_n = self.kwargs.pop("sampling_n", 100)
+        sampling_random_state = self.kwargs.pop("sampling_random_state", 0)
+        return (
+            data.sample(n=sampling_n, random_state=sampling_random_state)
+            .to_pandas()
+            .sort_index()
+        )
+
+
+class LinePlot(SamplingPlot):
+    @property
+    def _kind(self) -> typing.Literal["line"]:
+        return "line"
+
+
+class AreaPlot(SamplingPlot):
+    @property
+    def _kind(self) -> typing.Literal["area"]:
+        return "area"
+
+
+class ScatterPlot(SamplingPlot):
+    @property
+    def _kind(self) -> typing.Literal["scatter"]:
+        return "scatter"

Diff for: bigframes/operations/plotting.py

@@ -12,24 +12,73 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Optional, Sequence
+import typing
 
 import bigframes_vendored.pandas.plotting._core as vendordt
 
 import bigframes.constants as constants
 import bigframes.operations._matplotlib as bfplt
 
 
-class PlotAccessor:
+class PlotAccessor(vendordt.PlotAccessor):
     __doc__ = vendordt.PlotAccessor.__doc__
 
     def __init__(self, data) -> None:
         self._parent = data
 
-    def hist(self, by: Optional[Sequence[str]] = None, bins: int = 10, **kwargs):
+    def hist(
+        self, by: typing.Optional[typing.Sequence[str]] = None, bins: int = 10, **kwargs
+    ):
         if kwargs.pop("backend", None) is not None:
             raise NotImplementedError(
                 f"Only support matplotlib backend for now. {constants.FEEDBACK_LINK}"
             )
-        # Calls matplotlib backend to plot the data.
         return bfplt.plot(self._parent.copy(), kind="hist", by=by, bins=bins, **kwargs)
+
+    def line(
+        self,
+        x: typing.Optional[typing.Hashable] = None,
+        y: typing.Optional[typing.Hashable] = None,
+        **kwargs,
+    ):
+        return bfplt.plot(
+            self._parent.copy(),
+            kind="line",
+            x=x,
+            y=y,
+            **kwargs,
+        )
+
+    def area(
+        self,
+        x: typing.Optional[typing.Hashable] = None,
+        y: typing.Optional[typing.Hashable] = None,
+        stacked: bool = True,
+        **kwargs,
+    ):
+        return bfplt.plot(
+            self._parent.copy(),
+            kind="area",
+            x=x,
+            y=y,
+            stacked=stacked,
+            **kwargs,
+        )
+
+    def scatter(
+        self,
+        x: typing.Optional[typing.Hashable] = None,
+        y: typing.Optional[typing.Hashable] = None,
+        s: typing.Union[typing.Hashable, typing.Sequence[typing.Hashable]] = None,
+        c: typing.Union[typing.Hashable, typing.Sequence[typing.Hashable]] = None,
+        **kwargs,
+    ):
+        return bfplt.plot(
+            self._parent.copy(),
+            kind="scatter",
+            x=x,
+            y=y,
+            s=s,
+            c=c,
+            **kwargs,
+        )

Diff for: tests/system/small/operations/test_plot.py renamed to tests/system/small/operations/test_plotting.py

@@ -12,9 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import numpy as np
 import pandas._testing as tm
 import pytest
 
+import bigframes.pandas as bpd
+
 
 def _check_legend_labels(ax, labels):
     """
@@ -166,3 +169,67 @@ def test_hist_kwargs_ticks_props(scalars_dfs):
     for i in range(len(pd_xlables)):
         tm.assert_almost_equal(ylabels[i].get_fontsize(), pd_ylables[i].get_fontsize())
         tm.assert_almost_equal(ylabels[i].get_rotation(), pd_ylables[i].get_rotation())
+
+
+def test_line(scalars_dfs):
+    scalars_df, scalars_pandas_df = scalars_dfs
+    col_names = ["int64_col", "float64_col", "int64_too", "bool_col"]
+    ax = scalars_df[col_names].plot.line()
+    pd_ax = scalars_pandas_df[col_names].plot.line()
+    tm.assert_almost_equal(ax.get_xticks(), pd_ax.get_xticks())
+    tm.assert_almost_equal(ax.get_yticks(), pd_ax.get_yticks())
+    for line, pd_line in zip(ax.lines, pd_ax.lines):
+        # Compare y coordinates between the lines
+        tm.assert_almost_equal(line.get_data()[1], pd_line.get_data()[1])
+
+
+def test_area(scalars_dfs):
+    scalars_df, scalars_pandas_df = scalars_dfs
+    col_names = ["int64_col", "float64_col", "int64_too"]
+    ax = scalars_df[col_names].plot.area(stacked=False)
+    pd_ax = scalars_pandas_df[col_names].plot.area(stacked=False)
+    tm.assert_almost_equal(ax.get_xticks(), pd_ax.get_xticks())
+    tm.assert_almost_equal(ax.get_yticks(), pd_ax.get_yticks())
+    for line, pd_line in zip(ax.lines, pd_ax.lines):
+        # Compare y coordinates between the lines
+        tm.assert_almost_equal(line.get_data()[1], pd_line.get_data()[1])
+
+
+def test_scatter(scalars_dfs):
+    scalars_df, scalars_pandas_df = scalars_dfs
+    col_names = ["int64_col", "float64_col", "int64_too", "bool_col"]
+    ax = scalars_df[col_names].plot.scatter(x="int64_col", y="float64_col")
+    pd_ax = scalars_pandas_df[col_names].plot.scatter(x="int64_col", y="float64_col")
+    tm.assert_almost_equal(ax.get_xticks(), pd_ax.get_xticks())
+    tm.assert_almost_equal(ax.get_yticks(), pd_ax.get_yticks())
+    tm.assert_almost_equal(
+        ax.collections[0].get_sizes(), pd_ax.collections[0].get_sizes()
+    )
+
+
+def test_sampling_plot_args_n():
+    df = bpd.DataFrame(np.arange(1000), columns=["one"])
+    ax = df.plot.line()
+    assert len(ax.lines) == 1
+    # Default sampling_n is 100
+    assert len(ax.lines[0].get_data()[1]) == 100
+
+    ax = df.plot.line(sampling_n=2)
+    assert len(ax.lines) == 1
+    assert len(ax.lines[0].get_data()[1]) == 2
+
+
+def test_sampling_plot_args_random_state():
+    df = bpd.DataFrame(np.arange(1000), columns=["one"])
+    ax_0 = df.plot.line()
+    ax_1 = df.plot.line()
+    ax_2 = df.plot.line(sampling_random_state=100)
+    ax_3 = df.plot.line(sampling_random_state=100)
+
+    # Setting a fixed sampling_random_state guarantees reproducible plotted sampling.
+    tm.assert_almost_equal(ax_0.lines[0].get_data()[1], ax_1.lines[0].get_data()[1])
+    tm.assert_almost_equal(ax_2.lines[0].get_data()[1], ax_3.lines[0].get_data()[1])
+
+    msg = "numpy array are different"
+    with pytest.raises(AssertionError, match=msg):
+        tm.assert_almost_equal(ax_0.lines[0].get_data()[1], ax_2.lines[0].get_data()[1])