Merging GitHub pr 269

[wyli]

Status

READY

Description

merging https://github.com/NifTK/NiftyNet/pull/269 support of single or multiple optimisers in applications: use case 1 (original version)

self.optimiser = tf.train.Opimiser(...)
grads = self.optimiser.computer_gradient(...)
gradients_collector.add_to_collection(grads)

use case 2 (extended)

self.optimiser = tf.train.Optimiser(...)
grads['subnet_1'] = self.optimiser.compute_gradient(...)
grads['subnet_2'] = self.optimiser.compute_gradient(...)
gradients_collector.add_to_collection(grads)

use case 3 (extended)

self.optimiser['subnet_1'] = tf.train.Optimiser(...)
self.optimiser['subnet_2'] = tf.train.Optimiser(...)
grads['subnet_1'] = self.optimiser['subnet-1'].compute_gradient(...)
grads['subnet_2'] = self.optimiser['subnet-2'].compute_gradient(...)
gradients_collector.add_to_collection(grads)

Types of changes

• [x] New feature (non-breaking change which adds functionality)
• [x] My code follows the code style of this project.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.