diff options
Diffstat (limited to 'src/pkg/math/sin.go')
-rw-r--r-- | src/pkg/math/sin.go | 29 |
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; } |