Merge pull request #16 from mkborregaard/add-extrema

Add `extrema`

Author: mlubin

src/NaNMath.jl

@@ -120,6 +120,35 @@ function minimum{T<:AbstractFloat}(x::Vector{T})
     return result
 end
 
+"""
+NaNMath.extrema(A)
+
+##### Args:
+* `A`: A one dimensional array of floating point numbers
+
+##### Returns:
+*    Returns the minimum and maximum of all elements in the array, ignoring NaN's.
+
+##### Examples:
+```julia
+using NaNMath as nm
+nm.extrema([1., 2., NaN]) # result: 1.0, 2.0
+```
+"""
+function extrema{T<:AbstractFloat}(x::Vector{T})
+    resultmin, resultmax = convert(eltype(x), NaN), convert(eltype(x), NaN)
+    for i in x
+        if !isnan(i)
+            if (isnan(resultmin) || i < resultmin)
+                resultmin = i
+            elseif (isnan(resultmax) || i > resultmax)
+                resultmax = i
+            end
+        end
+    end
+    return resultmin, resultmax
+end
+
 """
 NaNMath.mean(A)
 

test/runtests.jl

@@ -12,6 +12,7 @@ using Base.Test
 @test NaNMath.sum([1f0, 2f0, NaN32]) === 3.0f0
 @test NaNMath.maximum([1., 2., NaN]) == 2.0
 @test NaNMath.minimum([1., 2., NaN]) == 1.0
+@test NaNMath.extrema([1., 2., NaN]) == (1.0, 2.0)
 @test NaNMath.mean([1., 2., NaN]) == 1.5
 @test NaNMath.var([1., 2., NaN]) == 0.5
 @test NaNMath.std([1., 2., NaN]) == 0.7071067811865476