吴恩达机器学习(二)——单变量线性回归(Linear Regression with One Variable) 1、模型表示 在监督学习中我们有一个数据集,这个数据集被称训练集(Training Set) 符号定义: m表示训练样本的数量 x表示输入变量/特征 y表示输出变量/预测的目标变量 (x,y)表示一个训练样本 (x(i), y(i))表示第i个训练样本(i...
defload_exdata(filename):data=[]withopen(filename,'r')asf:forlineinf.readlines():line=line.split(',')current=[int(item)foriteminline]#5.5277,9.1302data.append(current)returndata data=load_exdata('ex1data2.txt');data=np.array(data,np.int64)x=data[:,(0,1)].reshape((-1,2))y=dat...
(一)单变量线性回归 Linear Regression with One Variable (二)多变量线性回归 Linear Regression with Multiple Variables (三)逻辑回归 Logistic Regression (四)正则化与过拟合问题 Regularization/The Problem of Overfitting (五)神经网络的表示 Neural Networks:Representation (六)神经网络的学习 Neural Networks:Lear...
import math; def sum_of_gradient(x, y, thetas): """计算梯度向量,参数分别是x和y轴点坐标数据以及方程参数""" m = len(x); grad0 = 1.0 / m * sum([(thetas[0] + thetas[1] * x[i] - y[i]) for i in range(m)]) grad1 = 1.0 / m * sum([(thetas[0] + thetas[1] *...
2. Gradient descent for multiple variable 下面来看一下多变量下梯度下降算法的定义: Hypothesis : Parameters : 共n+1个参数 Cost Function : Gadient Descent : Repeat { simultaneously update for every } 原来单变量的梯度下降算法与现在对变量的梯度下降算法比较,最关键的就是一定要同时进行更新。
、GradientDescentinPracticeI-FeatureScaling特征缩放(featuresscaling) 使不同特征的取值范围变得接近,从而使算法更快收敛,迭代次数减少: 这里将...week2-2.MultivariteLinearRegression一、MultipleFeatures多变量(multiplefeatures/variable)的一些定义: 改写后
Linear Regression with Multiple Variables. 1. Multivariate Linear Regression I would like to give full credits to the respective authors as these are my personal python notebooks taken from deep learning courses from Andrew Ng, Data School and Udemy :) This is a simple python notebook hosted ...
[Section 1] Multiple Features [Section 2] Gradient Descent for Multiple Variables [Section 3] Gradient Descent in Practice I - Feature Scaling [Section 4] Gradient Descent in Practice II - Learning Rate [Section 5] Features and Polynomial Regression ...
Linear regression with multiple variables(多特征的线型回归)算法实例_梯度下降解法(Gradient DesentMulti)以及正规方程解法(Normal Equation),%第一列为sizeofHouse(feet^2),第二列为numberofbedroom,第三列为priceofHouse12104,3,39990021600,3,32990032400,3,3690004
一、Linear Regression 主要分为Linear Regression with One Variable & Linear Regression with Multiple Variables Linear Regression with One Variable 简单地说就是一个自变量一个因变量,且二者的关系近似可以用一条直线去拟合。 例如房价与面积的关系,就可以近似看成单变量线性回归问题 ...