rasterFilename=r"F:\农作物分类材料\测试\jingkou9chuli.tif"为遥感影像,vectorFilename=r"F:\农作物分类材料\测试\jingkou_roi.shp",为样本,python用随机森林算法进行分类并最佳指数因子(Optimum Index Factor,OIF)建立最优波段特征组合
时间: 2023-06-30 22:11:03 浏览: 118
好的,您可以按照以下步骤使用Python进行分类并建立最优波段特征组合:
1. 导入必要的库
```python
import os
import numpy as np
import pandas as pd
import geopandas as gpd
from rasterio.plot import show
from sklearn.ensemble import RandomForestClassifier
from sklearn.metrics import accuracy_score
from sklearn.model_selection import train_test_split
```
2. 读取遥感影像和样本
```python
# 读取遥感影像
rasterFilename = r"F:\农作物分类材料\测试\jingkou9chuli.tif"
raster = rasterio.open(rasterFilename)
# 显示影像
show(raster)
# 读取样本
vectorFilename = r"F:\农作物分类材料\测试\jingkou_roi.shp"
samples = gpd.read_file(vectorFilename)
```
3. 提取样本的特征值和类别
```python
# 提取样本的特征值和类别
bands = raster.read() # 读取所有波段
n_samples = len(samples) # 样本数量
n_bands = bands.shape[0] # 波段数
# 初始化特征矩阵和类别向量
X = np.zeros((n_samples, n_bands))
y = np.zeros(n_samples)
# 遍历每个样本,提取特征值和类别
for i, row in samples.iterrows():
# 获取样本的几何信息
geom = row.geometry
# 获取样本所在像元的行列号
col, row = raster.index(geom.centroid.x, geom.centroid.y)
# 提取样本的特征值
X[i, :] = bands[:, row, col]
# 提取样本的类别
y[i] = row['class']
```
4. 划分训练集和测试集
```python
# 划分训练集和测试集
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=0)
```
5. 训练随机森林分类器
```python
# 训练随机森林分类器
clf = RandomForestClassifier(n_estimators=100, max_depth=None, random_state=0)
clf.fit(X_train, y_train)
```
6. 预测测试集并计算准确率
```python
# 预测测试集并计算准确率
y_pred = clf.predict(X_test)
accuracy = accuracy_score(y_test, y_pred)
print("Accuracy:", accuracy)
```
7. 计算各个波段的重要性
```python
# 计算各个波段的重要性
importances = clf.feature_importances_
for i, imp in enumerate(importances):
print("Band {}: Importance = {:.3f}".format(i+1, imp))
```
8. 计算最优指数因子(OIF)并选择最优波段组合
```python
# 计算最优指数因子(OIF)并选择最优波段组合
n_bands = bands.shape[0] # 波段数
n_combinations = n_bands * (n_bands - 1) // 2 # 组合数
oif_list = np.zeros(n_combinations)
k = 0
for i in range(n_bands - 1):
for j in range(i + 1, n_bands):
# 计算指数因子
oif = (importances[i] - importances[j]) / (importances[i] + importances[j])
oif_list[k] = oif
k += 1
# 获取最大的指数因子
max_oif = oif_list.max()
# 获取最优波段组合
band_indices = np.where(oif_list == max_oif)[0][0]
band1_index = band_indices // n_bands
band2_index = band_indices % n_bands
best_bands = [band1_index, band2_index]
print("Best bands:", best_bands)
```
9. 可视化最优波段组合
```python
# 可视化最优波段组合
show(bands[[band1_index, band2_index], :, :])
```
以上是使用随机森林算法进行分类并建立最优波段特征组合的Python代码,您可以根据实际情况进行调整和优化。
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