test case for large angles in trig functions
R=rsc
https://golang.org/cl/157160
diff --git a/src/pkg/math/all_test.go b/src/pkg/math/all_test.go
index 0999228..60ce6de 100644
--- a/src/pkg/math/all_test.go
+++ b/src/pkg/math/all_test.go
@@ -169,6 +169,7 @@
}
return d < e;
}
+func kindaclose(a, b float64) bool { return tolerance(a, b, 1e-8) }
func close(a, b float64) bool { return tolerance(a, b, 1e-14) }
func veryclose(a, b float64) bool { return tolerance(a, b, 4e-16) }
@@ -274,6 +275,42 @@
}
}
+// Check that math functions of high angle values
+// return similar results to low angle values
+func TestLargeSin(t *testing.T) {
+ large := float64(100000 * Pi);
+ for i := 0; i < len(vf); i++ {
+ f1 := Sin(vf[i]);
+ f2 := Sin(vf[i] + large);
+ if !kindaclose(f1, f2) {
+ t.Errorf("Sin(%g) = %g, want %g\n", vf[i]+large, f1, f2)
+ }
+ }
+}
+
+func TestLargeCos(t *testing.T) {
+ large := float64(100000 * Pi);
+ for i := 0; i < len(vf); i++ {
+ f1 := Cos(vf[i]);
+ f2 := Cos(vf[i] + large);
+ if !kindaclose(f1, f2) {
+ t.Errorf("Cos(%g) = %g, want %g\n", vf[i]+large, f1, f2)
+ }
+ }
+}
+
+
+func TestLargeTan(t *testing.T) {
+ large := float64(100000 * Pi);
+ for i := 0; i < len(vf); i++ {
+ f1 := Tan(vf[i]);
+ f2 := Tan(vf[i] + large);
+ if !kindaclose(f1, f2) {
+ t.Errorf("Tan(%g) = %g, want %g\n", vf[i]+large, f1, f2)
+ }
+ }
+}
+
// Check that math constants are accepted by compiler
// and have right value (assumes strconv.Atof works).
// http://code.google.com/p/go/issues/detail?id=201
