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path: root/src/pkg/math/sin.go
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Diffstat (limited to 'src/pkg/math/sin.go')
-rw-r--r--src/pkg/math/sin.go29
1 files changed, 14 insertions, 15 deletions
diff --git a/src/pkg/math/sin.go b/src/pkg/math/sin.go
index 779a86e94..973aef554 100644
--- a/src/pkg/math/sin.go
+++ b/src/pkg/math/sin.go
@@ -7,34 +7,33 @@ package math
func sinus(x float64, quad int) float64 {
// Coefficients are #3370 from Hart & Cheney (18.80D).
- const
- (
- P0 = .1357884097877375669092680e8;
+ const (
+ P0 = .1357884097877375669092680e8;
P1 = -.4942908100902844161158627e7;
- P2 = .4401030535375266501944918e6;
+ P2 = .4401030535375266501944918e6;
P3 = -.1384727249982452873054457e5;
- P4 = .1459688406665768722226959e3;
- Q0 = .8644558652922534429915149e7;
- Q1 = .4081792252343299749395779e6;
- Q2 = .9463096101538208180571257e4;
- Q3 = .1326534908786136358911494e3;
+ P4 = .1459688406665768722226959e3;
+ Q0 = .8644558652922534429915149e7;
+ Q1 = .4081792252343299749395779e6;
+ Q2 = .9463096101538208180571257e4;
+ Q3 = .1326534908786136358911494e3;
)
if x < 0 {
x = -x;
quad = quad+2;
}
- x = x * (2/Pi); /* underflow? */
+ x = x*(2/Pi); /* underflow? */
var y float64;
if x > 32764 {
var e float64;
e, y = Modf(x);
- e = e + float64(quad);
+ e = e+float64(quad);
_, f := Modf(0.25*e);
quad = int(e - 4*f);
} else {
k := int32(x);
- y = x - float64(k);
- quad = (quad + int(k)) & 3;
+ y = x-float64(k);
+ quad = (quad+int(k))&3;
}
if quad&1 != 0 {
@@ -45,8 +44,8 @@ func sinus(x float64, quad int) float64 {
}
yy := y*y;
- temp1 := ((((P4*yy+P3)*yy+P2)*yy+P1)*yy+P0)*y;
- temp2 := ((((yy+Q3)*yy+Q2)*yy+Q1)*yy+Q0);
+ temp1 := ((((P4*yy + P3)*yy + P2)*yy + P1)*yy + P0)*y;
+ temp2 := ((((yy+Q3)*yy + Q2)*yy + Q1)*yy + Q0);
return temp1/temp2;
}