Copyright | (c) Justin Le 2018 |
---|---|
License | BSD3 |
Maintainer | justin@jle.im |
Stability | experimental |
Portability | non-portable |
Safe Haskell | None |
Language | Haskell2010 |
Synopsis
- class Backprop a where
- zeroNum :: Num a => a -> a
- addNum :: Num a => a -> a -> a
- oneNum :: Num a => a -> a
- zeroVec :: (Vector v a, Backprop a) => v a -> v a
- addVec :: (Vector v a, Backprop a) => v a -> v a -> v a
- oneVec :: (Vector v a, Backprop a) => v a -> v a
- zeroVecNum :: (Vector v a, Num a) => v a -> v a
- oneVecNum :: (Vector v a, Num a) => v a -> v a
- zeroFunctor :: (Functor f, Backprop a) => f a -> f a
- addIsList :: (IsList a, Backprop (Item a)) => a -> a -> a
- addAsList :: Backprop b => (a -> [b]) -> ([b] -> a) -> a -> a -> a
- oneFunctor :: (Functor f, Backprop a) => f a -> f a
- genericZero :: (Generic a, GZero (Rep a)) => a -> a
- genericAdd :: (Generic a, GAdd (Rep a)) => a -> a -> a
- genericOne :: (Generic a, GOne (Rep a)) => a -> a
- newtype ABP f a = ABP {
- runABP :: f a
- newtype NumBP a = NumBP {
- runNumBP :: a
- newtype NumVec v a = NumVec {
- runNumVec :: v a
- class GZero f
- class GAdd f
- class GOne f
Backpropagatable types
class Backprop a where Source #
Class of values that can be backpropagated in general.
For instances of Num
, these methods can be given by zeroNum
,
addNum
, and oneNum
. There are also generic options given in
Numeric.Backprop.Class for functors, IsList
instances, and Generic
instances.
instanceBackprop
Double
wherezero
=zeroNum
add
=addNum
one
=oneNum
If you leave the body of an instance declaration blank, GHC Generics
will be used to derive instances if the type has a single constructor
and each field is an instance of Backprop
.
To ensure that backpropagation works in a sound way, should obey the laws:
- identity
Also implies preservation of information, making
an
illegal implementation for lists and vectors.zipWith
(+
)
This is only expected to be true up to potential "extra zeroes" in x
and y
in the result.
- commutativity
- associativity
- idempotence
- unital
Note that not all values in the backpropagation process needs all of
these methods: Only the "final result" needs one
, for example. These
are all grouped under one typeclass for convenience in defining
instances, and also to talk about sensible laws. For fine-grained
control, use the "explicit" versions of library functions (for example,
in Numeric.Backprop.Explicit) instead of Backprop
based ones.
This typeclass replaces the reliance on Num
of the previous API
(v0.1). Num
is strictly more powerful than Backprop
, and is
a stronger constraint on types than is necessary for proper
backpropagating. In particular, fromInteger
is a problem for many
types, preventing useful backpropagation for lists, variable-length
vectors (like Data.Vector) and variable-size matrices from linear
algebra libraries like hmatrix and accelerate.
Since: 0.2.0.0
Nothing
"Zero out" all components of a value. For scalar values, this
should just be
. For vectors and matrices, this should
set all components to zero, the additive identity.const
0
Should be idempotent:
Should be as lazy as possible. This behavior is observed for all instances provided by this library.
See zeroNum
for a pre-built definition for instances of Num
and
zeroFunctor
for a definition for instances of Functor
. If left
blank, will automatically be genericZero
, a pre-built definition
for instances of Generic
whose fields are all themselves
instances of Backprop
.
Add together two values of a type. To combine contributions of gradients, so should be information-preserving:
Should be as strict as possible. This behavior is observed for all instances provided by this library.
See addNum
for a pre-built definition for instances of Num
and
addIsList
for a definition for instances of IsList
. If left
blank, will automatically be genericAdd
, a pre-built definition
for instances of Generic
with one constructor whose fields are
all themselves instances of Backprop
.
One all components of a value. For scalar values, this should
just be
. For vectors and matrices, this should set all
components to one, the multiplicative identity.const
1
As the library uses it, the most important law is:
That is,
is the gradient of the identity function with
respect to its input.one
x
Ideally should be idempotent:
Should be as lazy as possible. This behavior is observed for all instances provided by this library.
See oneNum
for a pre-built definition for instances of Num
and
oneFunctor
for a definition for instances of Functor
. If left
blank, will automatically be genericOne
, a pre-built definition
for instances of Generic
whose fields are all themselves
instances of Backprop
.
zero :: (Generic a, GZero (Rep a)) => a -> a Source #
"Zero out" all components of a value. For scalar values, this
should just be
. For vectors and matrices, this should
set all components to zero, the additive identity.const
0
Should be idempotent:
Should be as lazy as possible. This behavior is observed for all instances provided by this library.
See zeroNum
for a pre-built definition for instances of Num
and
zeroFunctor
for a definition for instances of Functor
. If left
blank, will automatically be genericZero
, a pre-built definition
for instances of Generic
whose fields are all themselves
instances of Backprop
.
add :: (Generic a, GAdd (Rep a)) => a -> a -> a Source #
Add together two values of a type. To combine contributions of gradients, so should be information-preserving:
Should be as strict as possible. This behavior is observed for all instances provided by this library.
See addNum
for a pre-built definition for instances of Num
and
addIsList
for a definition for instances of IsList
. If left
blank, will automatically be genericAdd
, a pre-built definition
for instances of Generic
with one constructor whose fields are
all themselves instances of Backprop
.
one :: (Generic a, GOne (Rep a)) => a -> a Source #
One all components of a value. For scalar values, this should
just be
. For vectors and matrices, this should set all
components to one, the multiplicative identity.const
1
As the library uses it, the most important law is:
That is,
is the gradient of the identity function with
respect to its input.one
x
Ideally should be idempotent:
Should be as lazy as possible. This behavior is observed for all instances provided by this library.
See oneNum
for a pre-built definition for instances of Num
and
oneFunctor
for a definition for instances of Functor
. If left
blank, will automatically be genericOne
, a pre-built definition
for instances of Generic
whose fields are all themselves
instances of Backprop
.
Instances
Backprop Double Source # | |
Backprop Float Source # | |
Backprop Int Source # | |
Backprop Integer Source # | |
Backprop Natural Source # | Since: 0.2.1.0 |
Backprop Word Source # | Since: 0.2.2.0 |
Backprop Word8 Source # | Since: 0.2.2.0 |
Backprop Word16 Source # | Since: 0.2.2.0 |
Backprop Word32 Source # | Since: 0.2.2.0 |
Backprop Word64 Source # | Since: 0.2.2.0 |
Backprop () Source # |
|
Backprop Void Source # | |
Backprop a => Backprop [a] Source # |
|
Backprop a => Backprop (Maybe a) Source # |
|
Integral a => Backprop (Ratio a) Source # | |
RealFloat a => Backprop (Complex a) Source # | |
Backprop a => Backprop (First a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Last a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Option a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Identity a) Source # | |
Backprop a => Backprop (First a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Last a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Dual a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Sum a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (Product a) Source # | Since: 0.2.2.0 |
Backprop a => Backprop (NonEmpty a) Source # |
|
Backprop a => Backprop (IntMap a) Source # |
|
Backprop a => Backprop (Seq a) Source # |
|
(Unbox a, Backprop a) => Backprop (Vector a) Source # | |
(Storable a, Backprop a) => Backprop (Vector a) Source # | |
(Prim a, Backprop a) => Backprop (Vector a) Source # | |
Backprop a => Backprop (Vector a) Source # | |
Backprop (Label field) Source # | Since: 0.2.6.3 |
Backprop a => Backprop (Identity a) Source # | Since: 0.2.6.3 |
Backprop a => Backprop (Thunk a) Source # | Since: 0.2.6.3 |
Backprop t => Backprop (ElField ((,) s t)) Source # | Since: 0.2.6.3 |
Num a => Backprop (NumBP a) Source # | |
Backprop a => Backprop (r -> a) Source # |
Since: 0.2.2.0 |
Backprop (V1 p) Source # | Since: 0.2.2.0 |
Backprop (U1 p) Source # | Since: 0.2.2.0 |
(Backprop a, Backprop b) => Backprop (a, b) Source # |
|
(Backprop a, Backprop b) => Backprop (Arg a b) Source # | Since: 0.2.2.0 |
Backprop (Proxy a) Source # | |
(Backprop a, Ord k) => Backprop (Map k a) Source # |
|
Backprop (SField field) Source # | Since: 0.2.6.3 |
(Applicative f, Backprop a) => Backprop (ABP f a) Source # | |
(Vector v a, Num a) => Backprop (NumVec v a) Source # | |
(Backprop a, Reifies s W) => Backprop (BVar s a) Source # | Since: 0.2.2.0 |
(Backprop a, Backprop b, Backprop c) => Backprop (a, b, c) Source # |
|
(Backprop a, Applicative m) => Backprop (Kleisli m r a) Source # | Since: 0.2.2.0 |
Backprop w => Backprop (Const w a) Source # | Since: 0.2.2.0 |
(ReifyConstraint Backprop f rs, RMap rs, RApply rs, IsoXRec f rs) => Backprop (XRec f rs) Source # | Since: 0.2.6.3 |
Backprop (HKD t a) => Backprop (XData t a) Source # | Since: 0.2.6.3 |
(ReifyConstraint Backprop f rs, RMap rs, RApply rs, RecApplicative rs, NatToInt (RLength rs), RPureConstrained (IndexableField rs) rs) => Backprop (ARec f rs) Source # | Since: 0.2.6.3 |
(ReifyConstraint Backprop f rs, RMap rs, RApply rs, Storable (Rec f rs)) => Backprop (SRec f rs) Source # | Since: 0.2.6.3 |
(ReifyConstraint Backprop f rs, RMap rs, RApply rs) => Backprop (Rec f rs) Source # | Since: 0.2.6.3 |
Backprop w => Backprop (Const w a) Source # | Since: 0.2.6.3 |
Backprop a => Backprop (K1 i a p) Source # | Since: 0.2.2.0 |
(Backprop (f p), Backprop (g p)) => Backprop ((f :*: g) p) Source # | Since: 0.2.2.0 |
(Backprop a, Backprop b, Backprop c, Backprop d) => Backprop (a, b, c, d) Source # |
|
(Backprop (f a), Backprop (g a)) => Backprop (Product f g a) Source # | Since: 0.2.2.0 |
Backprop (f p) => Backprop (M1 i c f p) Source # | Since: 0.2.2.0 |
Backprop (f (g a)) => Backprop ((f :.: g) a) Source # | Since: 0.2.6.3 |
(Backprop a, Backprop b, Backprop c, Backprop d, Backprop e) => Backprop (a, b, c, d, e) Source # |
|
Backprop (f (g a)) => Backprop (Compose f g a) Source # | Since: 0.2.2.0 |
Backprop (f (g a)) => Backprop (Compose f g a) Source # | Since: 0.2.6.3 |
Backprop (op (f a) (g a)) => Backprop (Lift op f g a) Source # | Since: 0.2.6.3 |
Derived methods
zeroVecNum :: (Vector v a, Num a) => v a -> v a Source #
:: Backprop b | |
=> (a -> [b]) | convert to list (should form isomorphism) |
-> ([b] -> a) | convert from list (should form isomorphism) |
-> a | |
-> a | |
-> a |
add
for types that are isomorphic to a list.
Automatically pads the end of the "shorter" value with zeroes.
Newtype
A newtype wrapper over an f a
for
that gives
a free Applicative
fBackprop
instance (as well as Num
etc. instances).
Useful for performing backpropagation over functions that require some
monadic context (like IO
) to perform.
Since: 0.2.1.0
Instances
Monad f => Monad (ABP f) Source # | |
Functor f => Functor (ABP f) Source # | |
Applicative f => Applicative (ABP f) Source # | |
Foldable f => Foldable (ABP f) Source # | |
Defined in Numeric.Backprop.Class fold :: Monoid m => ABP f m -> m # foldMap :: Monoid m => (a -> m) -> ABP f a -> m # foldr :: (a -> b -> b) -> b -> ABP f a -> b # foldr' :: (a -> b -> b) -> b -> ABP f a -> b # foldl :: (b -> a -> b) -> b -> ABP f a -> b # foldl' :: (b -> a -> b) -> b -> ABP f a -> b # foldr1 :: (a -> a -> a) -> ABP f a -> a # foldl1 :: (a -> a -> a) -> ABP f a -> a # elem :: Eq a => a -> ABP f a -> Bool # maximum :: Ord a => ABP f a -> a # minimum :: Ord a => ABP f a -> a # | |
Traversable f => Traversable (ABP f) Source # | |
Alternative f => Alternative (ABP f) Source # | |
MonadPlus f => MonadPlus (ABP f) Source # | |
Eq (f a) => Eq (ABP f a) Source # | |
(Applicative f, Floating a) => Floating (ABP f a) Source # | |
(Applicative f, Fractional a) => Fractional (ABP f a) Source # | |
(Typeable f, Typeable a, Data (f a)) => Data (ABP f a) Source # | |
Defined in Numeric.Backprop.Class gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ABP f a -> c (ABP f a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (ABP f a) # toConstr :: ABP f a -> Constr # dataTypeOf :: ABP f a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (ABP f a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (ABP f a)) # gmapT :: (forall b. Data b => b -> b) -> ABP f a -> ABP f a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ABP f a -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ABP f a -> r # gmapQ :: (forall d. Data d => d -> u) -> ABP f a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> ABP f a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> ABP f a -> m (ABP f a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ABP f a -> m (ABP f a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ABP f a -> m (ABP f a) # | |
(Applicative f, Num a) => Num (ABP f a) Source # | |
Ord (f a) => Ord (ABP f a) Source # | |
Read (f a) => Read (ABP f a) Source # | |
Show (f a) => Show (ABP f a) Source # | |
Generic (ABP f a) Source # | |
NFData (f a) => NFData (ABP f a) Source # | |
Defined in Numeric.Backprop.Class | |
(Applicative f, Backprop a) => Backprop (ABP f a) Source # | |
type Rep (ABP f a) Source # | |
Defined in Numeric.Backprop.Class |
A newtype wrapper over an instance of Num
that gives a free
Backprop
instance.
Useful for things like DerivingVia, or for avoiding orphan instances.
Since: 0.2.1.0
Instances
Monad NumBP Source # | |
Functor NumBP Source # | |
Applicative NumBP Source # | |
Foldable NumBP Source # | |
Defined in Numeric.Backprop.Class fold :: Monoid m => NumBP m -> m # foldMap :: Monoid m => (a -> m) -> NumBP a -> m # foldr :: (a -> b -> b) -> b -> NumBP a -> b # foldr' :: (a -> b -> b) -> b -> NumBP a -> b # foldl :: (b -> a -> b) -> b -> NumBP a -> b # foldl' :: (b -> a -> b) -> b -> NumBP a -> b # foldr1 :: (a -> a -> a) -> NumBP a -> a # foldl1 :: (a -> a -> a) -> NumBP a -> a # elem :: Eq a => a -> NumBP a -> Bool # maximum :: Ord a => NumBP a -> a # minimum :: Ord a => NumBP a -> a # | |
Traversable NumBP Source # | |
Eq a => Eq (NumBP a) Source # | |
Floating a => Floating (NumBP a) Source # | |
Fractional a => Fractional (NumBP a) Source # | |
Data a => Data (NumBP a) Source # | |
Defined in Numeric.Backprop.Class gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> NumBP a -> c (NumBP a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (NumBP a) # toConstr :: NumBP a -> Constr # dataTypeOf :: NumBP a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (NumBP a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (NumBP a)) # gmapT :: (forall b. Data b => b -> b) -> NumBP a -> NumBP a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> NumBP a -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> NumBP a -> r # gmapQ :: (forall d. Data d => d -> u) -> NumBP a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> NumBP a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> NumBP a -> m (NumBP a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> NumBP a -> m (NumBP a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> NumBP a -> m (NumBP a) # | |
Num a => Num (NumBP a) Source # | |
Ord a => Ord (NumBP a) Source # | |
Read a => Read (NumBP a) Source # | |
Show a => Show (NumBP a) Source # | |
Generic (NumBP a) Source # | |
NFData a => NFData (NumBP a) Source # | |
Defined in Numeric.Backprop.Class | |
Num a => Backprop (NumBP a) Source # | |
type Rep (NumBP a) Source # | |
Defined in Numeric.Backprop.Class |
Newtype wrapper around a v a
for
, that gives
a more efficient Vector
v aBackprop
instance for long vectors when a
is an
instance of Num
. The normal Backprop
instance for vectors will map
zero
or one
over all items; this instance will completely ignore the
contents of the original vector and instead produce a new vector of the
same length, with all 0
or 1
using the Num
instance of a
(essentially using zeroVecNum
and oneVecNum
instead of zeroVec
and
oneVec
).
add
is essentially the same as normal, but using +
instead of the
type's add
.
Since: 0.2.4.0
Instances
Monad v => Monad (NumVec v) Source # | |
Functor v => Functor (NumVec v) Source # | |
Applicative v => Applicative (NumVec v) Source # | |
Foldable v => Foldable (NumVec v) Source # | |
Defined in Numeric.Backprop.Class fold :: Monoid m => NumVec v m -> m # foldMap :: Monoid m => (a -> m) -> NumVec v a -> m # foldr :: (a -> b -> b) -> b -> NumVec v a -> b # foldr' :: (a -> b -> b) -> b -> NumVec v a -> b # foldl :: (b -> a -> b) -> b -> NumVec v a -> b # foldl' :: (b -> a -> b) -> b -> NumVec v a -> b # foldr1 :: (a -> a -> a) -> NumVec v a -> a # foldl1 :: (a -> a -> a) -> NumVec v a -> a # elem :: Eq a => a -> NumVec v a -> Bool # maximum :: Ord a => NumVec v a -> a # minimum :: Ord a => NumVec v a -> a # | |
Traversable v => Traversable (NumVec v) Source # | |
Alternative v => Alternative (NumVec v) Source # | |
MonadPlus v => MonadPlus (NumVec v) Source # | |
Eq (v a) => Eq (NumVec v a) Source # | |
(Typeable v, Typeable a, Data (v a)) => Data (NumVec v a) Source # | |
Defined in Numeric.Backprop.Class gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> NumVec v a -> c (NumVec v a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (NumVec v a) # toConstr :: NumVec v a -> Constr # dataTypeOf :: NumVec v a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (NumVec v a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (NumVec v a)) # gmapT :: (forall b. Data b => b -> b) -> NumVec v a -> NumVec v a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> NumVec v a -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> NumVec v a -> r # gmapQ :: (forall d. Data d => d -> u) -> NumVec v a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> NumVec v a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> NumVec v a -> m (NumVec v a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> NumVec v a -> m (NumVec v a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> NumVec v a -> m (NumVec v a) # | |
Ord (v a) => Ord (NumVec v a) Source # | |
Read (v a) => Read (NumVec v a) Source # | |
Show (v a) => Show (NumVec v a) Source # | |
Generic (NumVec v a) Source # | |
NFData (v a) => NFData (NumVec v a) Source # | |
Defined in Numeric.Backprop.Class | |
(Vector v a, Num a) => Backprop (NumVec v a) Source # | |
type Rep (NumVec v a) Source # | |
Defined in Numeric.Backprop.Class |
Generics
Helper class for automatically deriving zero
using GHC Generics.
gzero
Instances
GZero (V1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
GZero (U1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
Backprop a => GZero (K1 i a :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
(GZero f, GZero g) => GZero (f :+: g) Source # | |
Defined in Numeric.Backprop.Class | |
(GZero f, GZero g) => GZero (f :*: g) Source # | |
Defined in Numeric.Backprop.Class | |
GZero f => GZero (M1 i c f) Source # | |
Defined in Numeric.Backprop.Class | |
GZero f => GZero (f :.: g) Source # | |
Defined in Numeric.Backprop.Class |
Helper class for automatically deriving add
using GHC Generics.
gadd
Instances
GAdd (V1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
GAdd (U1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
Backprop a => GAdd (K1 i a :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
(GAdd f, GAdd g) => GAdd (f :*: g) Source # | |
Defined in Numeric.Backprop.Class | |
GAdd f => GAdd (M1 i c f) Source # | |
Defined in Numeric.Backprop.Class | |
GAdd f => GAdd (f :.: g) Source # | |
Defined in Numeric.Backprop.Class |
Helper class for automatically deriving one
using GHC Generics.
gone
Instances
GOne (V1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
GOne (U1 :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
Backprop a => GOne (K1 i a :: Type -> Type) Source # | |
Defined in Numeric.Backprop.Class | |
(GOne f, GOne g) => GOne (f :+: g) Source # | |
Defined in Numeric.Backprop.Class | |
(GOne f, GOne g) => GOne (f :*: g) Source # | |
Defined in Numeric.Backprop.Class | |
GOne f => GOne (M1 i c f) Source # | |
Defined in Numeric.Backprop.Class | |
GOne f => GOne (f :.: g) Source # | |
Defined in Numeric.Backprop.Class |