Why my iteration loss and train net output is the same, which ought to be different?

[Yanxin Yin]

Hi, everyone. I'm a beginner of Caffe and when I try to fine-tune the pertained AlexNet, I got the log as follows:

I0803 20:09:21.164162  7764 solver.cpp:244]     Train net output #0: loss = 0.159686 (* 1 = 0.159686 loss)

I0803 20:09:21.164175  7764 sgd_solver.cpp:106] Iteration 2040, lr = 0.001

I0803 20:09:46.981901  7764 solver.cpp:228] Iteration 2060, loss = 0.123431

I0803 20:09:46.981994  7764 solver.cpp:244]     Train net output #0: loss = 0.123431 (* 1 = 0.123431 loss)

I0803 20:09:46.982007  7764 sgd_solver.cpp:106] Iteration 2060, lr = 0.001

I0803 20:10:12.966456  7764 solver.cpp:228] Iteration 2080, loss = 0.139679

I0803 20:10:12.966558  7764 solver.cpp:244]     Train net output #0: loss = 0.139679 (* 1 = 0.139679 loss)

I0803 20:10:12.966579  7764 sgd_solver.cpp:106] Iteration 2080, lr = 0.001

I0803 20:10:38.951323  7764 solver.cpp:228] Iteration 2100, loss = 0.101742

I0803 20:10:38.951407  7764 solver.cpp:244]     Train net output #0: loss = 0.101742 (* 1 = 0.101742 loss)

I0803 20:10:38.951421  7764 sgd_solver.cpp:106] Iteration 2100, lr = 0.001

I0803 20:11:04.938468  7764 solver.cpp:228] Iteration 2120, loss = 0.0833068

I0803 20:11:04.938514  7764 solver.cpp:244]     Train net output #0: loss = 0.0833068 (* 1 = 0.0833068 loss)

I0803 20:11:04.938526  7764 sgd_solver.cpp:106] Iteration 2120, lr = 0.001

I0803 20:11:30.921013  7764 solver.cpp:228] Iteration 2140, loss = 0.0965971

I0803 20:11:30.921097  7764 solver.cpp:244]     Train net output #0: loss = 0.0965971 (* 1 = 0.0965971 loss)

I0803 20:11:30.921109  7764 sgd_solver.cpp:106] Iteration 2140, lr = 0.001

I0803 20:11:56.998575  7764 solver.cpp:228] Iteration 2160, loss = 0.121011

I0803 20:11:56.998627  7764 solver.cpp:244]     Train net output #0: loss = 0.121011 (* 1 = 0.121011 loss)

I0803 20:11:56.998641  7764 sgd_solver.cpp:106] Iteration 2160, lr = 0.001

I0803 20:12:23.315218  7764 solver.cpp:228] Iteration 2180, loss = 0.135258

I0803 20:12:23.315304  7764 solver.cpp:244]     Train net output #0: loss = 0.135258 (* 1 = 0.135258 loss)

I0803 20:12:23.315317  7764 sgd_solver.cpp:106] Iteration 2180, lr = 0.001

I0803 20:12:49.630429  7764 solver.cpp:228] Iteration 2200, loss = 0.12079

I0803 20:12:49.630476  7764 solver.cpp:244]     Train net output #0: loss = 0.12079 (* 1 = 0.12079 loss)

I0803 20:12:49.630487  7764 sgd_solver.cpp:106] Iteration 2200, lr = 0.001

I0803 20:13:15.949908  7764 solver.cpp:228] Iteration 2220, loss = 0.138279

I0803 20:13:15.950016  7764 solver.cpp:244]     Train net output #0: loss = 0.138279 (* 1 = 0.138279 loss)

I0803 20:13:15.950033  7764 sgd_solver.cpp:106] Iteration 2220, lr = 0.001

I'm wondering why the iteration loss and the train net output is the same. They should be different right? Since there's no similar issue, I really don't know what's going on. Can someone help? My appreciation in advance. Thanks a lot!