B ӻd /@s^dZddlmZddlmZddlmZddlmZddlm Z ddlm Z ddlm Z dd l m Z dd lmZe d Gd d d Ze ddGdddeZe ddGdddeZe ddGdddeZe ddGdddeZe ddGd d!d!eZeZeZeZeZeZeZeZeZe d"d#d$Ze d%d,d'd(Ze d)d*d+Z d&S)-z@Constraints: functions that impose constraints on weight values.) tensor_shape)backend)deserialize_keras_object)serialize_keras_object) array_ops)control_flow_ops)math_ops) keras_export) doc_controlszkeras.constraints.Constraintc@s eZdZdZddZddZdS) ConstraintaKBase class for weight constraints. A `Constraint` instance works like a stateless function. Users who subclass this class should override the `__call__` method, which takes a single weight parameter and return a projected version of that parameter (e.g. normalized or clipped). Constraints can be used with various Keras layers via the `kernel_constraint` or `bias_constraint` arguments. Here's a simple example of a non-negative weight constraint: >>> class NonNegative(tf.keras.constraints.Constraint): ... ... def __call__(self, w): ... return w * tf.cast(tf.math.greater_equal(w, 0.), w.dtype) >>> weight = tf.constant((-1.0, 1.0)) >>> NonNegative()(weight) >>> tf.keras.layers.Dense(4, kernel_constraint=NonNegative()) cCs|S)aGApplies the constraint to the input weight variable. By default, the inputs weight variable is not modified. Users should override this method to implement their own projection function. Args: w: Input weight variable. Returns: Projected variable (by default, returns unmodified inputs). )selfwr r U/var/www/html/venv/lib/python3.7/site-packages/tensorflow/python/keras/constraints.py__call__7s zConstraint.__call__cCsiS)aReturns a Python dict of the object config. A constraint config is a Python dictionary (JSON-serializable) that can be used to reinstantiate the same object. Returns: Python dict containing the configuration of the constraint object. r )r r r r get_configFs zConstraint.get_configN)__name__ __module__ __qualname____doc__rrr r r rr sr zkeras.constraints.MaxNormzkeras.constraints.max_normc@s6eZdZdZd ddZejddZejdd Zd S) MaxNorma/MaxNorm weight constraint. Constrains the weights incident to each hidden unit to have a norm less than or equal to a desired value. Also available via the shortcut function `tf.keras.constraints.max_norm`. Args: max_value: the maximum norm value for the incoming weights. axis: integer, axis along which to calculate weight norms. For instance, in a `Dense` layer the weight matrix has shape `(input_dim, output_dim)`, set `axis` to `0` to constrain each weight vector of length `(input_dim,)`. In a `Conv2D` layer with `data_format="channels_last"`, the weight tensor has shape `(rows, cols, input_depth, output_depth)`, set `axis` to `[0, 1, 2]` to constrain the weights of each filter tensor of size `(rows, cols, input_depth)`. rcCs||_||_dS)N) max_valueaxis)r rrr r r__init__kszMaxNorm.__init__cCsBttjt||jdd}t|d|j}||t|S)NT)rkeepdimsr) rsqrtr reduce_sumsquarercliprepsilon)r rnormsdesiredr r rroszMaxNorm.__call__cCs|j|jdS)N)rr)rr)r r r rrvszMaxNorm.get_configN)rr) rrrrrr do_not_generate_docsrrr r r rrRs rzkeras.constraints.NonNegzkeras.constraints.non_negc@seZdZdZddZdS)NonNegzyConstrains the weights to be non-negative. Also available via the shortcut function `tf.keras.constraints.non_neg`. cCs|tt|dtS)Ng)rcastZ greater_equalrZfloatx)r rr r rrszNonNeg.__call__N)rrrrrr r r rr${sr$zkeras.constraints.UnitNormzkeras.constraints.unit_normc@s6eZdZdZd ddZejddZejddZd S) UnitNormaConstrains the weights incident to each hidden unit to have unit norm. Also available via the shortcut function `tf.keras.constraints.unit_norm`. Args: axis: integer, axis along which to calculate weight norms. For instance, in a `Dense` layer the weight matrix has shape `(input_dim, output_dim)`, set `axis` to `0` to constrain each weight vector of length `(input_dim,)`. In a `Conv2D` layer with `data_format="channels_last"`, the weight tensor has shape `(rows, cols, input_depth, output_depth)`, set `axis` to `[0, 1, 2]` to constrain the weights of each filter tensor of size `(rows, cols, input_depth)`. rcCs ||_dS)N)r)r rr r rrszUnitNorm.__init__c Cs*|tttjt||jddS)NT)rr)rr rrrrr)r rr r rrs zUnitNorm.__call__cCs d|jiS)Nr)r)r r r rrszUnitNorm.get_configN)r) rrrrrr r#rrr r r rr&s r&zkeras.constraints.MinMaxNormzkeras.constraints.min_max_normc@s6eZdZdZd ddZejddZejd d Zd S) MinMaxNormaMinMaxNorm weight constraint. Constrains the weights incident to each hidden unit to have the norm between a lower bound and an upper bound. Also available via the shortcut function `tf.keras.constraints.min_max_norm`. Args: min_value: the minimum norm for the incoming weights. max_value: the maximum norm for the incoming weights. rate: rate for enforcing the constraint: weights will be rescaled to yield `(1 - rate) * norm + rate * norm.clip(min_value, max_value)`. Effectively, this means that rate=1.0 stands for strict enforcement of the constraint, while rate<1.0 means that weights will be rescaled at each step to slowly move towards a value inside the desired interval. axis: integer, axis along which to calculate weight norms. For instance, in a `Dense` layer the weight matrix has shape `(input_dim, output_dim)`, set `axis` to `0` to constrain each weight vector of length `(input_dim,)`. In a `Conv2D` layer with `data_format="channels_last"`, the weight tensor has shape `(rows, cols, input_depth, output_depth)`, set `axis` to `[0, 1, 2]` to constrain the weights of each filter tensor of size `(rows, cols, input_depth)`. ?rcCs||_||_||_||_dS)N) min_valuerrater)r r*rr+rr r rrszMinMaxNorm.__init__cCsXttjt||jdd}|jt||j|j d|j|}||t |S)NT)rr) rrrrrrr+rr*rr )r rr!r"r r rrs zMinMaxNorm.__call__cCs|j|j|j|jdS)N)r*rr+r)r*rr+r)r r r rrszMinMaxNorm.get_configN)r(r)r)r) rrrrrr r#rrr r r rr's  r'z"keras.constraints.RadialConstraintz#keras.constraints.radial_constraintc@s&eZdZdZejddZddZdS)RadialConstraintasConstrains `Conv2D` kernel weights to be the same for each radius. Also available via the shortcut function `tf.keras.constraints.radial_constraint`. For example, the desired output for the following 4-by-4 kernel: ``` kernel = [[v_00, v_01, v_02, v_03], [v_10, v_11, v_12, v_13], [v_20, v_21, v_22, v_23], [v_30, v_31, v_32, v_33]] ``` is this:: ``` kernel = [[v_11, v_11, v_11, v_11], [v_11, v_33, v_33, v_11], [v_11, v_33, v_33, v_11], [v_11, v_11, v_11, v_11]] ``` This constraint can be applied to any `Conv2D` layer version, including `Conv2DTranspose` and `SeparableConv2D`, and with either `"channels_last"` or `"channels_first"` data format. The method assumes the weight tensor is of shape `(rows, cols, input_depth, output_depth)`. cCs|j}|jdks|jdkr&td||\}}}}t|||||f}t|jtjtj |dddd}ttjtj |dddd||||fS)Nz8The weight tensor must be of rank 4, but is of shape: %s)rr) shapeZrank ValueErrorrZreshapeZmap_fn_kernel_constraintstackrZunstack)r rZw_shapeheightwidthZchannelsZkernelsr r rrs  zRadialConstraint.__call__c stjddgddggddtd}t|ddttt|ddfddfd d}ttt|ddd dd d}fd d}fd d}tj||||g| t ddggd\}}|S)zCRadially constraints a kernel with shape (height, width, channels).r,int32)dtyperrboolcsddfS)Nr,r r )kernelstartr rz5RadialConstraint._kernel_constraint..cs,ddftjdjdS)Nr,)rr)r7)rZzerosr7r )r9r:r rr;scSstjdddS)Nrr6)r7)rconstantr r r rr;!r<cSstjdddS)Nr,r6)r7)rr=r r r rr;"r<cs t|S)N)rless)indexargs)r:r rr;#r<cs(|dtj|||fdfS)Nr,)Zconstant_values)rpad)iarray)r9paddingr:r rbody_fn%s z4RadialConstraint._kernel_constraint..body_fnN)Zshape_invariants) rr=r0r%switchrZfloormodrZ while_loop get_shaperZ TensorShape)r r9Z kernel_shapeZ kernel_newr?Zwhile_conditionrE_r )r9rDr:rr2s(   z#RadialConstraint._kernel_constraintN)rrrrr r#rr2r r r rr-sr-zkeras.constraints.serializecCst|S)N)r) constraintr r r serializeBsrJzkeras.constraints.deserializeNcCst|t|ddS)NrI)Zmodule_objectscustom_objectsZprintable_module_name)rglobals)configrKr r r deserializeGs rNzkeras.constraints.getcCs^|dkr dSt|trt|St|tr>t|id}t|St|rJ|Stdt|dS)N) class_namerMz+Could not interpret constraint identifier: ) isinstancedictrNstrcallabler1) identifierrMr r rgetPs  rU)N)!rZtensorflow.python.frameworkrZtensorflow.python.kerasrZ+tensorflow.python.keras.utils.generic_utilsrrZtensorflow.python.opsrrrZ tensorflow.python.util.tf_exportr Ztensorflow.tools.docsr r rr$r&r'r-Zmax_normZnon_negZ unit_normZ min_max_normZradial_constraintZmaxnormZnonnegZunitnormrJrNrUr r r rsB         4( "8R