matplotlibで適当なプロットを書く

tick_params で軸上の値を消す

PathPatch で線を引く

text で任意の場所に字を書く

# モデルの複雑さと精度
import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as patches

plt.rcParams["font.family"] = "Hiragino Sans"
plt.rcParams["font.size"] = 24

train = [ (0., 0.),  (0.2, 1.),  (0.8, 1.0),  (1, 1.0),]
test = [ (0., 0.),  (0.2, 0.95),  (0.8, 0.8),  (1, 0.5),]
codes = [Path.MOVETO, Path.CURVE4, Path.CURVE4, Path.CURVE4, ]

fig, ax = plt.subplots()
fig.set_size_inches(12, 8, forward=True)

ax.add_patch(patches.PathPatch(Path(train, codes), facecolor='none', lw=3, edgecolor="red"))
ax.add_patch(patches.PathPatch(Path(test,  codes), facecolor='none', lw=3, edgecolor="blue", ls="--"))

ax.set_ylabel("精度")
ax.set_xlabel("小 <---- モデルの複雑度 ----> 大")
ax.tick_params(axis='x', which='both', bottom=False, top=False, labelbottom=False) 
ax.tick_params(axis='y', which='both', left=False, right=False, labelleft=False) 
ax.set_xlim(-0.05, 1.05)
ax.set_ylim(-0.05, 1.05)
ax.text(0.4, 0.9, '訓練')
ax.text(0.7, 0.6, 'テスト')
None