@@ -8,8 +8,6 @@ Typically each trial job gets a single configuration (e.g., hyperparameters) fro
The above cases can be supported by the same feature, i.e., multi-phase execution. To support those cases, basically a trial job should be able to request multiple configurations from tuner. Tuner is aware of whether two configuration requests are from the same trial job or different ones. Also in multi-phase a trial job can report multiple final results.
Note that, `nni.get_next_parameter()` and `nni.report_final_result()` should be called sequentially: __call the former one, then call the later one; and repeat this pattern__. If `nni.get_next_parameter()` is called multiple times consecutively, and then `nni.report_final_result()` is called once, the result is associated to the last configuration, which is retrieved from the last get_next_parameter call. So there is no result associated to previous get_next_parameter calls, and it may cause some multi-phase algorithm broken.
## Create multi-phase experiment
### Write trial code which leverages multi-phase:
...
...
@@ -23,6 +21,9 @@ It is pretty simple to use multi-phase in trial code, an example is shown below:
for i in range(5):
# get parameter from tuner
tuner_param = nni.get_next_parameter()
# nni.get_next_parameter returns None if there is no more hyper parameters can be generated by tuner.
if tuner_param is None:
break
# consume the params
# ...
...
...
@@ -32,6 +33,10 @@ It is pretty simple to use multi-phase in trial code, an example is shown below:
# ...
```
In multi-phase experiments, at each time the API ```nni.get_next_parameter()``` is called, it returns a new hyper parameter generated by tuner, then the trail code consume this new hyper parameter and report final result of this hyper parameter. `nni.get_next_parameter()` and `nni.report_final_result()` should be called sequentially: __call the former one, then call the later one; and repeat this pattern__. If `nni.get_next_parameter()` is called multiple times consecutively, and then `nni.report_final_result()` is called once, the result is associated to the last configuration, which is retrieved from the last get_next_parameter call. So there is no result associated to previous get_next_parameter calls, and it may cause some multi-phase algorithm broken.
Note that, ```nni.get_next_parameter``` returns None if there is no more hyper parameters can be generated by tuner.
__2. Experiment configuration__
To enable multi-phase, you should also add `multiPhase: true` in your experiment YAML configure file. If this line is not added, `nni.get_next_parameter()` would always return the same configuration.
