【卒論】Pythonで論文用の積み上げ棒グラフを綺麗に作成する

import matplotlib.pyplot as plt
import numpy as np

# 論文用の設定
# centimeters in inches
cm = 1/2.54 

plt.rcParams['font.family'] = 'Helavetica' # font familyの設定
plt.rcParams['mathtext.fontset'] = 'stix' # math fontの設定
plt.rcParams["font.size"] = 12
plt.rcParams['figure.subplot.bottom'] = 0.15
plt.rcParams['figure.subplot.left'] = 0.15
plt.rcParams['axes.axisbelow'] = True

# データ作成
x = np.array([1, 2, 3, 4, 5])
data = np.array([[70,50,30],
                 [30,40,30],
                 [50,90,40],
                 [60,40,50],
                 [30,40,50]])
label = ["2018","2019","2020","2021","2022"]

# グラフの定義
fig = plt.figure(figsize=(12*cm, 8*cm),dpi=300)
ax = fig.add_subplot(1,1,1)

# グラフのプロット1
B1 = ax.bar(x, 
            data[:,0], 
            tick_label=label, 
            align="center",
            color="#000000")

# グラフのプロット2
B2 = ax.bar(x, 
            data[:,1], 
            bottom=np.sum(data[:,0:1],axis=1),
            tick_label=label, 
            align="center",
            color="#858584")

# グラフのプロット3
B3 = ax.bar(x, 
            data[:,2], 
            bottom=np.sum(data[:,0:2],axis=1),
            tick_label=label, 
            align="center",
            color="#3d3c3c")

# 軸周りの設定
ax.set_ylim(0, 200)
ax.set_xlabel("Time")
ax.set_ylabel("Volume [XX]")
ax.grid(axis='y',linestyle='-', color='#e0e0e0')
# 凡例の設定
plt.legend((B1[0], B2[0], B3[0]), ("bar1", "bar2", "bar3"), 
            loc='lower center', 
            bbox_to_anchor=(.5, 1.1), 
            ncol=3,
            fancybox=False,
            edgecolor="k")

#セーブ
fig.savefig("bar_stacked.png", format="png", dpi=300, bbox_inches='tight')
fig.show()