caffe学习4——net

参考文献

1 The net jointly defines a function and its gradient by composition and auto-differentiation. 

2 The net is a set of layers connected in a computation graph – a directed acyclic graph (DAG) to be exact.保证前向后向通路，从硬盘加载数据到返回loss，进而进行分类等任务。

3 The net is defined as a set of layers and their connections in a plaintext modeling language.网是层的集合加上连接。

  例子：A simple logistic regression classifier is defined by

name: "LogReg"
layer {
  name: "mnist"
  type: "Data"
  top: "data"
  top: "label"
  data_param {
    source: "input_leveldb"
    batch_size: 64
  }
}
layer {
  name: "ip"
  type: "InnerProduct"
  bottom: "data"
  top: "ip"
  inner_product_param {
    num_output: 2
  }
}
layer {
  name: "loss"
  type: "SoftmaxWithLoss"
  bottom: "ip"
  bottom: "label"
  top: "loss"
}