Observers are a small framework that allow users to attach code to the execution of SimpleNets and Operators.
An example of an Observer is the TimeObserver, used as follows:
unique_ptr<TimeObserver<NetBase>> net_ob =
make_unique<TimeObserver<NetBase>>(net.get());
auto* ob = net->AttachObserver(std::move(net_ob));
net->Run();
LOG(INFO) << "av time children: " << ob->average_time_children();
LOG(INFO) << "av time: " << ob->average_time();
model.net.AttachObserver("TimeObserver")
ws.RunNet(model.net)
ob = model.net.GetObserver("TimeObserver")
print("av time children:", ob.average_time_children())
print("av time:", ob.average_time())
Creates a histogram for the values of weights and activations
model.net.AddObserver("HistogramObserver",
"histogram.txt", # filename
2014, # number of bins in histogram
32 # Dumping frequency
)
ws.RunNet(model.net)
This will generate a histogram for the activations and store it in histogram.txt
To implement an observer you must inherit from ObserverBase and implement the Start and Stop functions.
Observers are instantiated with a subject of a generic type, such as a Net or Operator. The observer framework is built to be generic enough to “observe” various other types, however.