Fix powers of negative integers

JuliaIntervals · May 22, 2019 · 2ab8526 · 2ab8526
1 parent a639347
commit 2ab8526
Showing 1 changed file with 12 additions and 8 deletions.
diff --git a/src/intervals/functions.jl b/src/intervals/functions.jl
@@ -209,19 +209,23 @@ function ^(x::Interval, n::Integer)  # fast integer power
         return Interval(zero(eltype(x)),
                         power_by_squaring(mag(x), n, RoundUp))
 
-    elseif x.lo > 0
-
-        a = power_by_squaring(x.lo, n, RoundDown)
-        b = power_by_squaring(x.hi, n, RoundUp)
-
-        return Interval(a, b)
+    #elseif x.lo > 0
 
     else
-        a = power_by_squaring(x.hi, n, RoundDown)
-        b = power_by_squaring(x.lo, n, RoundUp)
+
+         a = power_by_squaring(x.lo, n, RoundDown)
+         b = power_by_squaring(x.hi, n, RoundUp)
 
         return Interval(a, b)
+
     end
+    #
+    # else  # completely negative interval
+    #     a = power_by_squaring(x.lo, n, RoundDown)
+    #     b = power_by_squaring(x.hi, n, RoundUp)
+    #
+    #     return Interval(a, b)
+    #end
 
 end