python pic2:墙线图

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd

# ===== 强制中文字体设置 =====
plt.rcParams['font.sans-serif'] = ['SimHei', 'Microsoft YaHei', 'Arial Unicode MS']
plt.rcParams['axes.unicode_minus'] = False

# ========== 1. 读取Excel数据 ==========
file_path = r"D:/趋势图.xlsx"
df = pd.read_excel(file_path, engine='openpyxl')

# 直接读取原始数据（不提取数值）
interval_labels = df["区间"].values  # 原始区间标签
area_before = df["作业前面积"].values
area_after = df["作业后面积"].values

# 用序号作为X轴位置
x_positions = np.arange(len(interval_labels))

# ========== 2. 墙线图 ==========
fig, ax = plt.subplots(figsize=(14, 8), dpi=200)
ax.set_facecolor('white')
fig.patch.set_facecolor('white')

# ----- 2.1 作业前：蓝色半透明墙 -----
ax.fill_between(x_positions, 0, area_before,
                color='#4a9eff', alpha=0.35, label='作业前面积')
ax.plot(x_positions, area_before,
        color='#4a9eff', linewidth=3, marker='o', markersize=4,
        markerfacecolor='white', markeredgewidth=1.5, label='_nolegend_')

# ----- 2.2 作业后：橙色半透明墙（叠加）-----
ax.fill_between(x_positions, 0, area_after,
                color='#ff6b35', alpha=0.45, label='作业后面积')
ax.plot(x_positions, area_after,
        color='#ff6b35', linewidth=3.5, marker='s', markersize=5,
        markerfacecolor='white', markeredgewidth=2, label='_nolegend_')

# ----- 2.3 提升区域（填充）-----
ax.fill_between(x_positions, area_before, area_after,
                where=(area_after >= area_before),
                color='#f1c40f', alpha=0.25, interpolate=True, label='提升区域')

# ========== 3. 坐标轴美化 ==========
ax.set_xlabel('NDVI', fontsize=14, color='black', fontweight='bold')
ax.set_ylabel('面积 (万平方公里)', fontsize=14, color='black', fontweight='bold')
ax.tick_params(colors='black', labelsize=10)

# X轴刻度：替换 -0.0 和双减号
ax.set_xticks(x_positions)

clean_labels = []
for label in interval_labels:
    label_str = str(label)
    # 把 -0.0 替换成 0
    label_str = label_str.replace('-0.0', '0')
    # 把 -- 替换成 -（处理 -0.1--0.0 这种情况）
    label_str = label_str.replace('--', '-')
    clean_labels.append(label_str)

ax.set_xticklabels(clean_labels, rotation=0, ha='center',  fontsize=8)

# Y轴刻度（0-50，步长5）
ax.set_ylim(0, 50)
ax.set_yticks(np.arange(0, 51, 5))

# 网格线（浅灰色）
ax.grid(color='#cccccc', linestyle='--', linewidth=0.5, alpha=0.5)

# 边框
ax.spines['top'].set_visible(False)
ax.spines['right'].set_visible(False)
ax.spines['left'].set_color('black')
ax.spines['bottom'].set_color('black')

# ========== 4. 图例 ==========
ax.legend(loc='upper right', fontsize=12, facecolor='white',
          edgecolor='black', labelcolor='black', framealpha=0.9)

plt.tight_layout(pad=5.0)
plt.show()