Fix type instability in Newton 1D operator;

add version without derivative specified
JuliaIntervals · May 12, 2017 · 8006b70 · 8006b70
1 parent 410c9f5
commit 8006b70
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/src/newton.jl b/src/newton.jl
@@ -22,12 +22,17 @@ doc"""
 Single-variable Newton operator
 """
 function N{T}(f::Function, x::Interval{T}, deriv::Interval{T})
-    m = guarded_mid(f, x)
-    m = Interval(m)
+    m = Interval( guarded_mid(f, x) )
 
     m - (f(m) / deriv)
 end
 
+function N{T}(f::Function, x::Interval{T})
+    m = Interval( guarded_mid(f, x) )
+
+    m - (f(m) / ForwardDiff.derivative(f, x))
+end
+
 doc"""
 Multi-variable Newton operator.
 Requires the function to be defined using the `@intervalbox` macro.