diff options
Diffstat (limited to 'src/pkg/math/tan.go')
| -rw-r--r-- | src/pkg/math/tan.go | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/src/pkg/math/tan.go b/src/pkg/math/tan.go index a8e6b15c9..7287d80ef 100644 --- a/src/pkg/math/tan.go +++ b/src/pkg/math/tan.go @@ -12,15 +12,14 @@ package math // Tan returns the tangent of x. func Tan(x float64) float64 { // Coefficients are #4285 from Hart & Cheney. (19.74D) - const - ( + const ( P0 = -.1306820264754825668269611177e+5; - P1 = .1055970901714953193602353981e+4; + P1 = .1055970901714953193602353981e+4; P2 = -.1550685653483266376941705728e+2; - P3 = .3422554387241003435328470489e-1; - P4 = .3386638642677172096076369e-4; + P3 = .3422554387241003435328470489e-1; + P4 = .3386638642677172096076369e-4; Q0 = -.1663895238947119001851464661e+5; - Q1 = .4765751362916483698926655581e+4; + Q1 = .4765751362916483698926655581e+4; Q2 = -.1555033164031709966900124574e+3; ) @@ -30,14 +29,14 @@ func Tan(x float64) float64 { x = -x; sign = true; } - x = x * (4/Pi); /* overflow? */ + x = x*(4/Pi); /* overflow? */ var e float64; e, x = Modf(x); i := int32(e); - switch i & 3 { + switch i&3 { case 1: - x = 1 - x; + x = 1-x; flag = true; case 2: @@ -45,13 +44,13 @@ func Tan(x float64) float64 { flag = true; case 3: - x = 1 - x; + x = 1-x; sign = !sign; } xsq := x*x; - temp := ((((P4*xsq+P3)*xsq+P2)*xsq+P1)*xsq+P0)*x; - temp = temp/(((xsq+Q2)*xsq+Q1)*xsq+Q0); + temp := ((((P4*xsq + P3)*xsq + P2)*xsq + P1)*xsq + P0)*x; + temp = temp/(((xsq+Q2)*xsq + Q1)*xsq + Q0); if flag { if temp == 0 { |