利用上面的代码,帮我补全利用函数读取abalone.txt数据,并训练LWLR模型,比较不同k值下,模型在训练样本上的误差值
时间: 2024-03-10 18:46:02 浏览: 62
abalone.txt
好的,下面是一个完整的Python代码,包括数据读取、模型训练和误差计算:
```python
from numpy import *
# 读取数据
def loadDataSet(fileName):
numFeat = len(open(fileName).readline().split('\t')) - 1
dataMat = []
labelMat = []
fr = open(fileName)
for line in fr.readlines():
lineArr = []
curLine = line.strip().split('\t')
for i in range(numFeat):
lineArr.append(float(curLine[i]))
dataMat.append(lineArr)
labelMat.append(float(curLine[-1]))
return dataMat, labelMat
# 计算误差
def error(xArr, yArr, yHat):
return sum((yArr - yHat) ** 2)
# Locally Weighted Linear Regression局部加权线性回归
def lwlr(testPoint, xArr, yArr, k=1.0):
xMat = mat(xArr)
yMat = mat(yArr).T
m = shape(xMat)[0]
weights = mat(eye((m)))
for j in range(m):
diffMat = testPoint - xMat[j, :]
weights[j, j] = exp(diffMat * diffMat.T / (-2.0 * k ** 2))
xTx = xMat.T * (weights * xMat)
if linalg.det(xTx) == 0.0:
print("This matrix is singular, cannot do inverse")
return
ws = xTx.I * (xMat.T * (weights * yMat))
return testPoint * ws
# 训练LWLR模型并计算误差
def trainLWLR(xArr, yArr, k):
m = shape(xArr)[0]
yHat = zeros(m)
for i in range(m):
yHat[i] = lwlr(xArr[i], xArr, yArr, k)
return error(xArr, yArr, yHat)
# 加载数据
xArr, yArr = loadDataSet('abalone.txt')
# 比较不同k值下,模型在训练样本上的误差值
k_list = [0.1, 1, 10]
for k in k_list:
print('k={}'.format(k))
print('train error: {:.2f}'.format(trainLWLR(xArr, yArr, k)))
```
这个程序首先加载数据集,然后比较不同k值下,训练LWLR模型在训练样本上的误差值。其中,误差计算函数error(xArr, yArr, yHat)已经在上面补全了。Locally Weighted Linear Regression算法的实现使用lwlr(testPoint, xArr, yArr, k)函数,训练LWLR模型并计算误差的函数是trainLWLR(xArr, yArr, k)。
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