Wu deeplearning.ai C1W2 assignment2_2

Logistic Regression with a Neural Network mindset

Welcome to your first (required) programming assignment! You will build a logistic regression classifier to recognize cats. This assignment will step you through how to do this with a Neural Network mindset, and so will also hone your intuitions about deep learning.

Instructions:

• Do not use loops (for/while) in your code, unless the instructions explicitly ask you to do so.

You will learn to:

• Build the general architecture of a learning algorithm, including:
  • Initializing parameters
  • Calculating the cost function and its gradient
  • Using an optimization algorithm (gradient descent) 
• Gather all three functions above into a main model function, in the right order.

这边的主要任务就是构建一个logistics回归的二分分类器去分类猫，主要分为如下几步：

1）导入所需要的package，对data进行preprocessing

2）编写必要的Basic function，比如sigmoid、initialize_with_zeros等等

3）最后构建model，测试

下面详细展开：

1.数据的导入以及预处理

import numpy as np
import matplotlib.pyplot as plt
import h5py
import scipy
from PIL import Image
from scipy import ndimage
from lr_utils import lo