Merge pull request #11 from Evizero/sqrhinge

Bugfix SqrHingeLoss concerning consistency
lindahua · Oct 6, 2015 · edc49b0 · edc49b0
2 parents b7b66d6 + 60e3697
commit edc49b0
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Showing 2 changed files with 4 additions and 8 deletions.
diff --git a/src/loss.jl b/src/loss.jl
@@ -134,7 +134,6 @@ function value_and_deriv{T<:BlasReal}(loss::HuberLoss, p::T, y::T)
 end
 
 
-
 ## Hinge loss (for L1-SVM)
 #
 #   loss(p, y) := max(1 - y * p, 0)
@@ -160,14 +159,14 @@ end
 
 function value{T<:BlasReal}(::SqrHingeLoss, p::T, y::T)
     yp = y * p
-    yp >= one(T) ? zero(T) : half(abs2(nonneg(one(T) - yp)))
+    yp >= one(T) ? zero(T) : abs2(nonneg(one(T) - yp))
 end
 
-deriv{T<:BlasReal}(::SqrHingeLoss, p::T, y::T) = y * p < one(T) ? (p - y) : zero(T)
+deriv{T<:BlasReal}(::SqrHingeLoss, p::T, y::T) = y * p < one(T) ? 2(p - y) : zero(T)
 
 function value_and_deriv{T<:BlasReal}(::SqrHingeLoss, p::T, y::T)
     yp = y * p
-    yp >= one(T) ? (zero(T), zero(T)) : (half(abs2(one(T) - yp)), (p - y))
+    yp >= one(T) ? (zero(T), zero(T)) : (abs2(one(T) - yp), 2(p - y))
 end
 
 

diff --git a/test/uniloss.jl b/test/uniloss.jl
@@ -78,19 +78,16 @@ end
 verify_uniloss(HuberLoss(0.3), (p, y) -> _huberf(0.3, p, y), -2.0:0.25:2.0, -1.0:0.5:1.0)
 verify_uniloss(HuberLoss(0.5), (p, y) -> _huberf(0.5, p, y), -2.0:0.25:2.0, -1.0:0.5:1.0)
 
-
 # HingeLoss
 
 _hingef(u::Dual, y) = y * real(u) < 1.0 ? 1.0 - y * u : dual(0.0, 0.0)
 verify_uniloss(HingeLoss(), _hingef, -2.0:0.5:2.0, [-1.0, 1.0])
 
-
 # SquaredHingeLoss
 
-_sqrhingef(u::Dual, y) = y * real(u) < 1.0 ? .5(1.0 - y * u).^2 : dual(0.0, 0.0)
+_sqrhingef(u::Dual, y) = y * real(u) < 1.0 ? (1.0 - y * u).^2 : dual(0.0, 0.0)
 verify_uniloss(SqrHingeLoss(), _sqrhingef, -2.0:0.5:2.0, [-1.0, 1.0])
 
-
 # SmoothedHingeLoss
 
 function _sm_hingef(h::Float64, u::Dual, y)