Merge 64623e7 into a9b00c8

JuliaDiff · Jun 25, 2019 · 79eb94f · 79eb94f
2 parents a9b00c8 + 64623e7
commit 79eb94f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/rules.jl b/src/rules.jl
@@ -84,7 +84,7 @@ _abs_deriv(x) = signbit(x) ? -one(x) : one(x)
 @define_diffrule Base.:*(x, y) = :( $y                 ), :(  $x                )
 @define_diffrule Base.:/(x, y) = :( inv($y)            ), :( -($x / $y / $y)    )
 @define_diffrule Base.:\(x, y) = :( -($y / $x / $x)    ), :( inv($x)            )
-@define_diffrule Base.:^(x, y) = :( $y * ($x^($y - 1)) ), :(  ($x^$y) * log($x) )
+@define_diffrule Base.:^(x, y) = :( $y * ($x^($y - 1)) ), :( $x > 0 ? ($x^$y) * log($x) : NaN )
 
 if VERSION < v"0.7-"
     @define_diffrule Base.atan2(x, y)   = :( $y / ($x^2 + $y^2)                                 ), :( -$x / ($x^2 + $y^2)                                                     )