Files
lightgbm-org--lightgbm/tests/python_package_test/test_plotting.py
T
2026-07-13 13:27:18 +08:00

632 lines
24 KiB
Python

# coding: utf-8
import numpy as np
import pandas as pd
import pytest
from sklearn.model_selection import train_test_split
import lightgbm as lgb
from .utils import load_breast_cancer, make_synthetic_regression
@pytest.fixture(scope="function")
def matplotlib():
mpl = pytest.importorskip("matplotlib")
# use non-interactive, in-memory renderer
mpl.use("Agg")
return mpl
@pytest.fixture(scope="module")
def breast_cancer_split():
return train_test_split(*load_breast_cancer(return_X_y=True), test_size=0.1, random_state=1)
def _categorical_data(category_values_lower_bound, category_values_upper_bound):
X, y = load_breast_cancer(return_X_y=True)
X_df = pd.DataFrame()
rnd = np.random.RandomState(0)
n_cat_values = rnd.randint(category_values_lower_bound, category_values_upper_bound, size=X.shape[1])
for i in range(X.shape[1]):
bins = np.linspace(0, 1, num=n_cat_values[i] + 1)
X_df[f"cat_col_{i}"] = pd.qcut(X[:, i], q=bins, labels=range(n_cat_values[i])).as_unordered()
return X_df, y
@pytest.fixture(scope="module")
def train_data(breast_cancer_split):
X_train, _, y_train, _ = breast_cancer_split
return lgb.Dataset(X_train, y_train)
@pytest.fixture
def params():
return {"objective": "binary", "verbose": -1, "num_leaves": 3}
def test_plot_importance(params, breast_cancer_split, train_data, matplotlib):
X_train, _, y_train, _ = breast_cancer_split
gbm0 = lgb.train(params, train_data, num_boost_round=10)
ax0 = lgb.plot_importance(gbm0)
assert isinstance(ax0, matplotlib.axes.Axes)
assert ax0.get_title() == "Feature importance"
assert ax0.get_xlabel() == "Feature importance"
assert ax0.get_ylabel() == "Features"
assert len(ax0.patches) <= 30
gbm1 = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1)
gbm1.fit(X_train, y_train)
ax1 = lgb.plot_importance(gbm1, color="r", title="t", xlabel="x", ylabel="y")
assert isinstance(ax1, matplotlib.axes.Axes)
assert ax1.get_title() == "t"
assert ax1.get_xlabel() == "x"
assert ax1.get_ylabel() == "y"
assert len(ax1.patches) <= 30
for patch in ax1.patches:
assert patch.get_facecolor() == (1.0, 0, 0, 1.0) # red
ax2 = lgb.plot_importance(gbm0, color=["r", "y", "g", "b"], title=None, xlabel=None, ylabel=None)
assert isinstance(ax2, matplotlib.axes.Axes)
assert ax2.get_title() == ""
assert ax2.get_xlabel() == ""
assert ax2.get_ylabel() == ""
assert len(ax2.patches) <= 30
assert ax2.patches[0].get_facecolor() == (1.0, 0, 0, 1.0) # r
assert ax2.patches[1].get_facecolor() == (0.75, 0.75, 0, 1.0) # y
assert ax2.patches[2].get_facecolor() == (0, 0.5, 0, 1.0) # g
assert ax2.patches[3].get_facecolor() == (0, 0, 1.0, 1.0) # b
ax3 = lgb.plot_importance(
gbm0, title="t @importance_type@", xlabel="x @importance_type@", ylabel="y @importance_type@"
)
assert isinstance(ax3, matplotlib.axes.Axes)
assert ax3.get_title() == "t @importance_type@"
assert ax3.get_xlabel() == "x split"
assert ax3.get_ylabel() == "y @importance_type@"
assert len(ax3.patches) <= 30
ax4 = lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, xlim=(0, 30))
assert isinstance(ax4, matplotlib.axes.Axes)
assert ax4.get_title() == ""
assert ax4.get_xlabel() == ""
assert ax4.get_ylabel() == ""
assert ax4.get_xlim() == (0, 30)
assert len(ax4.patches) <= 30
with pytest.raises(TypeError, match="xlim must be a tuple of 2 elements."):
lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, xlim="not a tuple")
ax5 = lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, ylim=(0, 30))
assert isinstance(ax5, matplotlib.axes.Axes)
assert ax5.get_title() == ""
assert ax5.get_xlabel() == ""
assert ax5.get_ylabel() == ""
assert ax5.get_ylim() == (0, 30)
assert len(ax5.patches) <= 30
with pytest.raises(TypeError, match="ylim must be a tuple of 2 elements."):
lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, ylim="not a tuple")
ax6 = lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, figsize=(0, 30))
assert isinstance(ax6, matplotlib.axes.Axes)
assert ax6.get_title() == ""
assert ax6.get_xlabel() == ""
assert ax6.get_ylabel() == ""
assert list(ax6.get_figure().get_size_inches()) == [0, 30]
assert len(ax6.patches) <= 30
with pytest.raises(TypeError, match="figsize must be a tuple of 2 elements."):
lgb.plot_importance(gbm0, title=None, xlabel=None, ylabel=None, figsize="not a tuple")
# test max_num_features parameter
total_features = len(gbm0.feature_importance())
assert total_features > 5, "model must have more than 5 features to test max_num_features"
ax7 = lgb.plot_importance(gbm0, max_num_features=5)
assert isinstance(ax7, matplotlib.axes.Axes)
assert len(ax7.patches) == 5
# verify the 5 displayed features are the top 5 by importance
importance = gbm0.feature_importance()
feature_names = gbm0.feature_name()
sorted_pairs = sorted(zip(feature_names, importance, strict=True), key=lambda x: x[1])
top5_names = [name for name, _ in sorted_pairs[-5:]]
displayed_labels = [label.get_text() for label in ax7.get_yticklabels()]
assert displayed_labels == top5_names
gbm2 = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1, importance_type="gain")
gbm2.fit(X_train, y_train)
def get_bounds_of_first_patch(axes):
return axes.patches[0].get_extents().bounds
first_bar1 = get_bounds_of_first_patch(lgb.plot_importance(gbm1))
first_bar2 = get_bounds_of_first_patch(lgb.plot_importance(gbm1, importance_type="split"))
first_bar3 = get_bounds_of_first_patch(lgb.plot_importance(gbm1, importance_type="gain"))
first_bar4 = get_bounds_of_first_patch(lgb.plot_importance(gbm2))
first_bar5 = get_bounds_of_first_patch(lgb.plot_importance(gbm2, importance_type="split"))
first_bar6 = get_bounds_of_first_patch(lgb.plot_importance(gbm2, importance_type="gain"))
assert first_bar1 == first_bar2
assert first_bar1 == first_bar5
assert first_bar3 == first_bar4
assert first_bar3 == first_bar6
assert first_bar1 != first_bar3
def test_plot_importance_zero_splits(matplotlib):
X, y = load_breast_cancer(return_X_y=True)
model = lgb.train(
params={
"min_data_in_bin": X.shape[0] + 1,
"objective": "regression",
"verbose": -1,
},
train_set=lgb.Dataset(X, label=y),
num_boost_round=1,
)
with pytest.raises(ValueError, match="No non-zero feature importances found"):
lgb.plot_importance(model)
# ignore_zero=False should still produce a valid plot
ax = lgb.plot_importance(model, ignore_zero=False)
assert isinstance(ax, matplotlib.axes.Axes)
assert len(ax.patches) == X.shape[1]
def test_plot_split_value_histogram(params, breast_cancer_split, train_data, matplotlib):
X_train, _, y_train, _ = breast_cancer_split
gbm0 = lgb.train(params, train_data, num_boost_round=10)
ax0 = lgb.plot_split_value_histogram(gbm0, 27)
assert isinstance(ax0, matplotlib.axes.Axes)
assert ax0.get_title() == "Split value histogram for feature with index 27"
assert ax0.get_xlabel() == "Feature split value"
assert ax0.get_ylabel() == "Count"
assert len(ax0.patches) <= 2
gbm1 = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1)
gbm1.fit(X_train, y_train)
ax1 = lgb.plot_split_value_histogram(
gbm1,
gbm1.booster_.feature_name()[27],
figsize=(10, 5),
title="Histogram for feature @index/name@ @feature@",
xlabel="x",
ylabel="y",
color="r",
)
assert isinstance(ax1, matplotlib.axes.Axes)
title = f"Histogram for feature name {gbm1.booster_.feature_name()[27]}"
assert ax1.get_title() == title
assert ax1.get_xlabel() == "x"
assert ax1.get_ylabel() == "y"
assert len(ax1.patches) <= 2
for patch in ax1.patches:
assert patch.get_facecolor() == (1.0, 0, 0, 1.0) # red
ax2 = lgb.plot_split_value_histogram(
gbm0, 27, bins=10, color=["r", "y", "g", "b"], title=None, xlabel=None, ylabel=None
)
assert isinstance(ax2, matplotlib.axes.Axes)
assert ax2.get_title() == ""
assert ax2.get_xlabel() == ""
assert ax2.get_ylabel() == ""
assert len(ax2.patches) == 10
assert ax2.patches[0].get_facecolor() == (1.0, 0, 0, 1.0) # r
assert ax2.patches[1].get_facecolor() == (0.75, 0.75, 0, 1.0) # y
assert ax2.patches[2].get_facecolor() == (0, 0.5, 0, 1.0) # g
assert ax2.patches[3].get_facecolor() == (0, 0, 1.0, 1.0) # b
# test xlim parameter
ax3 = lgb.plot_split_value_histogram(gbm0, 27, xlim=(0, 100), title=None, xlabel=None, ylabel=None)
assert isinstance(ax3, matplotlib.axes.Axes)
assert ax3.get_title() == ""
assert ax3.get_xlabel() == ""
assert ax3.get_ylabel() == ""
assert ax3.get_xlim() == (0, 100)
with pytest.raises(TypeError, match="xlim must be a tuple of 2 elements."):
lgb.plot_split_value_histogram(gbm0, 27, xlim="not a tuple")
ax4 = lgb.plot_split_value_histogram(gbm0, 27, ylim=(0, 100), title=None, xlabel=None, ylabel=None)
assert isinstance(ax4, matplotlib.axes.Axes)
assert ax4.get_title() == ""
assert ax4.get_xlabel() == ""
assert ax4.get_ylabel() == ""
assert ax4.get_ylim() == (0, 100)
with pytest.raises(TypeError, match="ylim must be a tuple of 2 elements."):
lgb.plot_split_value_histogram(gbm0, 27, ylim="not a tuple")
with pytest.raises(
ValueError, match="Cannot plot split value histogram, because feature 0 was not used in splitting"
):
lgb.plot_split_value_histogram(gbm0, 0) # was not used in splitting
def test_plot_tree(breast_cancer_split, matplotlib):
pytest.importorskip("graphviz")
X_train, _, y_train, _ = breast_cancer_split
gbm = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1)
gbm.fit(X_train, y_train)
with pytest.raises(IndexError, match="tree_index is out of range."):
lgb.plot_tree(gbm, tree_index=83)
ax = lgb.plot_tree(gbm, tree_index=3, figsize=(15, 8), show_info=["split_gain"])
assert isinstance(ax, matplotlib.axes.Axes)
w, h = ax.axes.get_figure().get_size_inches()
assert int(w) == 15
assert int(h) == 8
def test_create_tree_digraph(tmp_path, breast_cancer_split):
graphviz = pytest.importorskip("graphviz")
X_train, _, y_train, _ = breast_cancer_split
constraints = [-1, 1] * int(X_train.shape[1] / 2)
gbm = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1, monotone_constraints=constraints)
gbm.fit(X_train, y_train)
with pytest.raises(IndexError, match="tree_index is out of range."):
lgb.create_tree_digraph(gbm, tree_index=83)
graph = lgb.create_tree_digraph(
gbm,
tree_index=3,
show_info=["split_gain", "internal_value", "internal_weight"],
name="Tree4",
node_attr={"color": "red"},
directory=tmp_path,
)
graph.render(view=False)
assert isinstance(graph, graphviz.Digraph)
assert graph.name == "Tree4"
assert len(graph.node_attr) == 1
assert graph.node_attr["color"] == "red"
assert len(graph.graph_attr) == 0
assert len(graph.edge_attr) == 0
graph_body = "".join(graph.body)
assert "leaf" in graph_body
assert "gain" in graph_body
assert "value" in graph_body
assert "weight" in graph_body
assert "#ffdddd" in graph_body
assert "#ddffdd" in graph_body
assert "data" not in graph_body
assert "count" not in graph_body
def test_tree_with_categories_below_max_category_values(tmp_path):
graphviz = pytest.importorskip("graphviz")
X_train, y_train = _categorical_data(2, 10)
params = {
"n_estimators": 10,
"num_leaves": 3,
"min_data_in_bin": 1,
"force_col_wise": True,
"deterministic": True,
"num_threads": 1,
"seed": 708,
"verbose": -1,
}
gbm = lgb.LGBMClassifier(**params)
gbm.fit(X_train, y_train)
with pytest.raises(IndexError, match="tree_index is out of range."):
lgb.create_tree_digraph(gbm, tree_index=83)
graph = lgb.create_tree_digraph(
gbm,
tree_index=3,
show_info=["split_gain", "internal_value", "internal_weight"],
name="Tree4",
node_attr={"color": "red"},
max_category_values=10,
directory=tmp_path,
)
graph.render(view=False)
assert isinstance(graph, graphviz.Digraph)
assert graph.name == "Tree4"
assert len(graph.node_attr) == 1
assert graph.node_attr["color"] == "red"
assert len(graph.graph_attr) == 0
assert len(graph.edge_attr) == 0
graph_body = "".join(graph.body)
assert "leaf" in graph_body
assert "gain" in graph_body
assert "value" in graph_body
assert "weight" in graph_body
assert "data" not in graph_body
assert "count" not in graph_body
assert "||...||" not in graph_body
def test_tree_with_categories_above_max_category_values(tmp_path):
graphviz = pytest.importorskip("graphviz")
X_train, y_train = _categorical_data(20, 30)
params = {
"n_estimators": 10,
"num_leaves": 3,
"min_data_in_bin": 1,
"force_col_wise": True,
"deterministic": True,
"num_threads": 1,
"seed": 708,
"verbose": -1,
}
gbm = lgb.LGBMClassifier(**params)
gbm.fit(X_train, y_train)
with pytest.raises(IndexError, match="tree_index is out of range."):
lgb.create_tree_digraph(gbm, tree_index=83)
graph = lgb.create_tree_digraph(
gbm,
tree_index=9,
show_info=["split_gain", "internal_value", "internal_weight"],
name="Tree4",
node_attr={"color": "red"},
max_category_values=4,
directory=tmp_path,
)
graph.render(view=False)
assert isinstance(graph, graphviz.Digraph)
assert graph.name == "Tree4"
assert len(graph.node_attr) == 1
assert graph.node_attr["color"] == "red"
assert len(graph.graph_attr) == 0
assert len(graph.edge_attr) == 0
graph_body = "".join(graph.body)
assert "leaf" in graph_body
assert "gain" in graph_body
assert "value" in graph_body
assert "weight" in graph_body
assert "data" not in graph_body
assert "count" not in graph_body
assert "||...||" in graph_body
@pytest.mark.parametrize("use_missing", [True, False])
@pytest.mark.parametrize("zero_as_missing", [True, False])
def test_numeric_split_direction(use_missing, zero_as_missing):
X, y = make_synthetic_regression()
rng = np.random.RandomState(0)
zero_mask = rng.rand(X.shape[0]) < 0.05
X[zero_mask, :] = 0
if use_missing:
nan_mask = ~zero_mask & (rng.rand(X.shape[0]) < 0.1)
X[nan_mask, :] = np.nan
ds = lgb.Dataset(X, y)
params = {
"num_leaves": 127,
"min_child_samples": 1,
"use_missing": use_missing,
"zero_as_missing": zero_as_missing,
}
bst = lgb.train(params, ds, num_boost_round=1)
case_with_zero = X[zero_mask][[0]]
expected_leaf_zero = bst.predict(case_with_zero, pred_leaf=True)[0]
node = bst.dump_model()["tree_info"][0]["tree_structure"]
while "decision_type" in node:
direction = lgb.plotting._determine_direction_for_numeric_split(
fval=case_with_zero[0][node["split_feature"]],
threshold=node["threshold"],
missing_type_str=node["missing_type"],
default_left=node["default_left"],
)
node = node["left_child"] if direction == "left" else node["right_child"]
assert node["leaf_index"] == expected_leaf_zero
if use_missing:
case_with_nan = X[nan_mask][[0]]
expected_leaf_nan = bst.predict(case_with_nan, pred_leaf=True)[0]
node = bst.dump_model()["tree_info"][0]["tree_structure"]
while "decision_type" in node:
direction = lgb.plotting._determine_direction_for_numeric_split(
fval=case_with_nan[0][node["split_feature"]],
threshold=node["threshold"],
missing_type_str=node["missing_type"],
default_left=node["default_left"],
)
node = node["left_child"] if direction == "left" else node["right_child"]
assert node["leaf_index"] == expected_leaf_nan
if zero_as_missing:
# zeros treated as missing -> same leaf as NaN
assert expected_leaf_zero == expected_leaf_nan
else:
# zeros are regular values -> different leaf from NaN
assert expected_leaf_zero != expected_leaf_nan
def test_example_case_in_tree_digraph():
pytest.importorskip("graphviz")
rng = np.random.RandomState(0)
x1 = rng.rand(100)
cat = rng.randint(1, 3, size=x1.size)
X = np.vstack([x1, cat]).T
y = x1 + 2 * cat
feature_name = ["x1", "cat"]
ds = lgb.Dataset(X, y, feature_name=feature_name, categorical_feature=["cat"])
num_round = 3
bst = lgb.train({"num_leaves": 7}, ds, num_boost_round=num_round)
mod = bst.dump_model()
example_case = X[[0]]
makes_categorical_splits = False
seen_indices = set()
for i in range(num_round):
graph = lgb.create_tree_digraph(bst, example_case=example_case, tree_index=i)
gbody = graph.body
node = mod["tree_info"][i]["tree_structure"]
while "decision_type" in node: # iterate through the splits
split_index = node["split_index"]
node_in_graph = [n for n in gbody if f"split{split_index}" in n and "->" not in n]
assert len(node_in_graph) == 1
seen_indices.add(gbody.index(node_in_graph[0]))
edge_to_node = [e for e in gbody if f"-> split{split_index}" in e]
if node["decision_type"] == "<=":
direction = lgb.plotting._determine_direction_for_numeric_split(
fval=example_case[0][node["split_feature"]],
threshold=node["threshold"],
missing_type_str=node["missing_type"],
default_left=node["default_left"],
)
else:
makes_categorical_splits = True
direction = lgb.plotting._determine_direction_for_categorical_split(
example_case[0][node["split_feature"]], node["threshold"]
)
node = node["left_child"] if direction == "left" else node["right_child"]
assert "color=blue" in node_in_graph[0]
if edge_to_node:
assert len(edge_to_node) == 1
assert "color=blue" in edge_to_node[0]
seen_indices.add(gbody.index(edge_to_node[0]))
# we're in a leaf now
leaf_index = node["leaf_index"]
leaf_in_graph = [n for n in gbody if f"leaf{leaf_index}" in n and "->" not in n]
edge_to_leaf = [e for e in gbody if f"-> leaf{leaf_index}" in e]
assert len(leaf_in_graph) == 1
assert "color=blue" in leaf_in_graph[0]
assert len(edge_to_leaf) == 1
assert "color=blue" in edge_to_leaf[0]
seen_indices.update([gbody.index(leaf_in_graph[0]), gbody.index(edge_to_leaf[0])])
# check that the rest of the elements have black color
remaining_elements = [e for i, e in enumerate(graph.body) if i not in seen_indices and "graph" not in e]
assert all("color=black" in e for e in remaining_elements)
# check that we got to the expected leaf
expected_leaf = bst.predict(example_case, start_iteration=i, num_iteration=1, pred_leaf=True)[0]
assert leaf_index == expected_leaf
assert makes_categorical_splits
@pytest.mark.parametrize("input_type", ["array", "dataframe"])
def test_empty_example_case_on_tree_digraph_raises_error(input_type):
pytest.importorskip("graphviz")
X, y = make_synthetic_regression()
if input_type == "dataframe":
pd = pytest.importorskip("pandas")
X = pd.DataFrame(X)
example_case = pd.DataFrame(X[:0])
else:
example_case = X[:0]
ds = lgb.Dataset(X, y)
bst = lgb.train({"num_leaves": 3}, ds, num_boost_round=1)
with pytest.raises(ValueError, match="example_case must have a single row."):
lgb.create_tree_digraph(bst, tree_index=0, example_case=example_case)
def test_plot_metrics(params, breast_cancer_split, train_data, matplotlib):
X_train, X_test, y_train, y_test = breast_cancer_split
test_data = lgb.Dataset(X_test, y_test, reference=train_data)
params.update({"metric": {"binary_logloss", "binary_error"}})
evals_result0 = {}
lgb.train(
params,
train_data,
valid_sets=[train_data, test_data],
valid_names=["v1", "v2"],
num_boost_round=10,
callbacks=[lgb.record_evaluation(evals_result0)],
)
with pytest.warns(UserWarning, match="More than one metric available, picking one to plot."):
ax0 = lgb.plot_metric(evals_result0)
assert isinstance(ax0, matplotlib.axes.Axes)
assert ax0.get_title() == "Metric during training"
assert ax0.get_xlabel() == "Iterations"
assert ax0.get_ylabel() in {"binary_logloss", "binary_error"}
legend_items = ax0.get_legend().get_texts()
assert len(legend_items) == 2
assert legend_items[0].get_text() == "v1"
assert legend_items[1].get_text() == "v2"
ax1 = lgb.plot_metric(evals_result0, metric="binary_error")
assert isinstance(ax1, matplotlib.axes.Axes)
assert ax1.get_title() == "Metric during training"
assert ax1.get_xlabel() == "Iterations"
assert ax1.get_ylabel() == "binary_error"
legend_items = ax1.get_legend().get_texts()
assert len(legend_items) == 2
assert legend_items[0].get_text() == "v1"
assert legend_items[1].get_text() == "v2"
ax2 = lgb.plot_metric(evals_result0, metric="binary_logloss", dataset_names=["v2"])
assert isinstance(ax2, matplotlib.axes.Axes)
assert ax2.get_title() == "Metric during training"
assert ax2.get_xlabel() == "Iterations"
assert ax2.get_ylabel() == "binary_logloss"
legend_items = ax2.get_legend().get_texts()
assert len(legend_items) == 1
assert legend_items[0].get_text() == "v2"
ax3 = lgb.plot_metric(
evals_result0,
metric="binary_logloss",
dataset_names=["v1"],
title="Metric @metric@",
xlabel="Iterations @metric@",
ylabel='Value of "@metric@"',
figsize=(5, 5),
dpi=600,
grid=False,
)
assert isinstance(ax3, matplotlib.axes.Axes)
assert ax3.get_title() == "Metric @metric@"
assert ax3.get_xlabel() == "Iterations @metric@"
assert ax3.get_ylabel() == 'Value of "binary_logloss"'
legend_items = ax3.get_legend().get_texts()
assert len(legend_items) == 1
assert legend_items[0].get_text() == "v1"
assert ax3.get_figure().get_figheight() == 5
assert ax3.get_figure().get_figwidth() == 5
assert ax3.get_figure().get_dpi() == 600
for grid_line in ax3.get_xgridlines():
assert not grid_line.get_visible()
for grid_line in ax3.get_ygridlines():
assert not grid_line.get_visible()
evals_result1 = {}
lgb.train(params, train_data, num_boost_round=10, callbacks=[lgb.record_evaluation(evals_result1)])
with pytest.raises(ValueError, match="eval results cannot be empty."):
lgb.plot_metric(evals_result1)
gbm2 = lgb.LGBMClassifier(n_estimators=10, num_leaves=3, verbose=-1)
gbm2.fit(X_train, y_train, eval_set=[(X_test, y_test)])
ax4 = lgb.plot_metric(gbm2, title=None, xlabel=None, ylabel=None)
assert isinstance(ax4, matplotlib.axes.Axes)
assert ax4.get_title() == ""
assert ax4.get_xlabel() == ""
assert ax4.get_ylabel() == ""
legend_items = ax4.get_legend().get_texts()
assert len(legend_items) == 1
assert legend_items[0].get_text() == "valid_0"
# test xlim parameter
ax5 = lgb.plot_metric(evals_result0, metric="binary_logloss", xlim=(0, 15), title=None, xlabel=None, ylabel=None)
assert isinstance(ax5, matplotlib.axes.Axes)
assert ax5.get_title() == ""
assert ax5.get_xlabel() == ""
assert ax5.get_ylabel() == ""
assert ax5.get_xlim() == (0, 15)
with pytest.raises(TypeError, match="xlim must be a tuple of 2 elements."):
lgb.plot_metric(evals_result0, metric="binary_logloss", xlim="not a tuple")
ax6 = lgb.plot_metric(evals_result0, metric="binary_logloss", ylim=(0, 15), title=None, xlabel=None, ylabel=None)
assert isinstance(ax6, matplotlib.axes.Axes)
assert ax6.get_title() == ""
assert ax6.get_xlabel() == ""
assert ax6.get_ylabel() == ""
assert ax6.get_ylim() == (0, 15)
with pytest.raises(TypeError, match="ylim must be a tuple of 2 elements."):
lgb.plot_metric(evals_result0, metric="binary_logloss", ylim="not a tuple")