@Override
public List<Product> getUserLike(Integer uid,Integer pid){
List<UserLook> userLooks = userLookMapper.getListByUid(uid, 5);
List<Product> products = new ArrayList<Product>();
int sum_xy = 0;
int sum_x = 0;
int sum_y = 0;
double sum_x2 = 0;
double sum_y2 = 0;
int n = 0;
for(UserLook userLook:userLooks) {
List<Product> pList = productService.findProductByRand(userLook.getCsid(), userLook.getPid(), 1);
if(pList!=null && pList.size()>0 && !pid.equals(pList.get(0).getPid())) {!
Product product = pList.get(0);
int sellNum = productService.getSellNum(product.getPid());
product.setSellNum(sellNum);
n += 1;
int x = userLook.getUid();
int y = userLook.getPid();
sum_xy += x * y;
sum_x += x;
sum_y += y;
sum_x2 += Math.pow(x, 2);
sum_y2 += Math.pow(y, 2);
double denominator = Math.sqrt(sum_x2 - Math.pow(sum_x, 2) / n) * Math.sqrt(sum_y2 - Math.pow(sum_y, 2) / n);
if(denominator==0) {
products.add(product);
}
}
}
return products;
}
uid是用户编号,pid商品编号csid商品分类的类别编号