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cmath: correct IsNaN for argument cmplx(Inf, NaN)

Browse Source 
R=rsc
CC=golang-dev
https://golang.org/cl/1705041
This commit is contained in:
Charles L. Dorian 2010-06-30 23:34:33 -07:00 committed by Russ Cox
parent 47c85ec97a
commit 9038de0373
2 changed files with 38 additions and 6 deletions
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36
src/pkg/cmath/cmath_test.go
View File

@ -38,8 +38,7 @@ var vc = []complex128{
// at http://keisan.casio.com/. More exact input values (array vc[], above)
// were obtained by printing them with "%.26f". The answers were calculated
// to 26 digits (by using the "Digit number" drop-down control of each
// calculator). Twenty-six digits were chosen so that the answers would be
// accurate even for a float128 type.
// calculator).
var abs = []float64{
9.2022120669932650313380972e+00,
@ -355,6 +354,28 @@ var vcExpSC = []complex128{
var expSC = []complex128{
NaN(),
}
var vcIsNaNSC = []complex128{
cmplx(math.Inf(-1), math.Inf(-1)),
cmplx(math.Inf(-1), math.NaN()),
cmplx(math.NaN(), math.Inf(-1)),
cmplx(0, math.NaN()),
cmplx(math.NaN(), 0),
cmplx(math.Inf(1), math.Inf(1)),
cmplx(math.Inf(1), math.NaN()),
cmplx(math.NaN(), math.Inf(1)),
cmplx(math.NaN(), math.NaN()),
}
var isNaNSC = []bool{
false,
false,
false,
true,
true,
false,
false,
false,
true,
}
var vcLogSC = []complex128{
NaN(),
}
@ -432,7 +453,7 @@ func alike(a, b float64) bool {
case a != a && b != b: // math.IsNaN(a) && math.IsNaN(b):
return true
case a == b:
return true
return math.Signbit(a) == math.Signbit(b)
}
return false
}
@ -454,7 +475,7 @@ func cAlike(a, b complex128) bool {
case IsNaN(a) && IsNaN(b):
return true
case a == b:
return true
return math.Signbit(real(a)) == math.Signbit(real(b)) && math.Signbit(imag(a)) == math.Signbit(imag(b))
}
return false
}
@ -591,6 +612,13 @@ func TestExp(t *testing.T) {
}
}
}
func TestIsNaN(t *testing.T) {
for i := 0; i < len(vcIsNaNSC); i++ {
if f := IsNaN(vcIsNaNSC[i]); isNaNSC[i] != f {
t.Errorf("IsNaN(%g) = %g, want %g\n", vcIsNaNSC[i], f, isNaNSC[i])
}
}
}
func TestLog(t *testing.T) {
for i := 0; i < len(vc); i++ {
if f := Log(vc[i]); !cVeryclose(log[i], f) {

8
src/pkg/cmath/isnan.go
View File

@ -6,9 +6,13 @@ package cmath
import "math"
// IsNaN returns true if either real(x) or imag(x) is NaN.
// IsNaN returns true if either real(x) or imag(x) is NaN
// and neither is an infinity.
func IsNaN(x complex128) bool {
if math.IsNaN(real(x)) || math.IsNaN(imag(x)) {
switch {
case math.IsInf(real(x), 0) || math.IsInf(imag(x), 0):
return false
case math.IsNaN(real(x)) || math.IsNaN(imag(x)):
return true
}
return false