in detection_voc_evaluator.py, Why observation is empty dict and return? about chainercv HOT 7 CLOSED

I am a foreigner , I can't read japanese, I googled a lot of chainer example, But most of them is written in japanese, I want to know how to write a evaluator extension?

from chainercv.

Well, I don't know much example other than ones in ChainerCV that modify Evaluator.

        observation = {}
        with reporter.report_scope(observation):
            reporter.report(report, target)
        return observation

This basically does observation.update(report).
By looking at the source code of the original Evaluator, you can find that our evaluator simply modified parts of it.

Actually, while trying to come up with an answer to your question, I realized that it can be simplified to return report!

As a side note, the context with reporter.report_score(observation) is useful when reporter.report is called inside of a function in the with block.
Here is an example.

import chainer
from chainer import reporter


def f():
    reporter.report({'a': 3})

if __name__ == '__main__':
    observation =  {}

    r = reporter.Reporter()

    with r:
        with reporter.report_scope(observation):
            f()

    print(observation)

EDIT:
Actually, I had to do reporter.report.
The with reporter.report_scope is needed to get the namespace of reported values (See Evaluator.__call__, where namespace is prepared).

from chainercv.

I just can't find where did it reported ?? in which log file path? I don't see any report F1 score or Accuracy in console print?

from chainercv.

If you use LogReport in your train loop, the values will be printed to a file.
By default, the log file is result/log.
(https://github.com/chainer/chainercv/blob/master/examples/faster_rcnn/train.py#L100)

from chainercv.

@yuyu2172 but you also use PrintReport

trainer.extend(extensions.PrintReport(
  | ['iteration', 'epoch', 'elapsed_time', 'lr',
  | 'main/loss',
  | 'main/roi_loc_loss',
  | 'main/roi_cls_loss',
  | 'main/rpn_loc_loss',
  | 'main/rpn_cls_loss',
  | 'validation/main/map',
  | ]), trigger=print_interval)
``` 

Does this 2 line conflict with each other, 
I did not found any report log in my linux filesystem. I am try to find.

from chainercv.

mAP gets recorded on the log file only when it gets evaluated.
You will find it in the log file at iteration 5000.

They don't conflict with each other.

from chainercv.

If you have more question, please reopen.

from chainercv.