autokeras: Specify hyperparameter ranges for blocks

Feature Description

We want to enable the users to specify the value ranges for any argument in the blocks. The following code example shows a typical use case. The users can specify the number of units in a DenseBlock to be either 10 or 20.

Code Example

import autokeras as ak
from kerastuner.engine.hyperparameters import Choice

input_node = ak.ImageInput()
output_node = ak.DenseBlock(num_units=Choice("num_units", [10, 20]))(input_node)
output_node = ak.ClassificationHead()(output_node)
model = ak.AutoModel(input_node, output_node)

Note

Each pull request should only change one hyperparameter in one of the blocks.

Solution

Example pull requests are #1419 #1425 . Here are the steps to follow:

1. You can just change any other argument in any other block supported by AutoKeras, as shown here.
2. Change the docstring. example
3. Make sure you imported the module. from kerastuner.engine import hyperparameters.
4. Change the typing of the argument. example
5. Change the saving mechanism to serialized objects. example
6. Change the loading mechanism to deserialized objects. example
7. Change how we initialize the hyperparameter to self. example Copy from where it is originally defined. example
8. Change how we use it. example