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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/math/tan.v | |
download | cli-tools-windows-master.tar.gz cli-tools-windows-master.tar.bz2 cli-tools-windows-master.zip |
Diffstat (limited to 'v_windows/v/vlib/math/tan.v')
-rw-r--r-- | v_windows/v/vlib/math/tan.v | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/v_windows/v/vlib/math/tan.v b/v_windows/v/vlib/math/tan.v new file mode 100644 index 0000000..b37287f --- /dev/null +++ b/v_windows/v/vlib/math/tan.v @@ -0,0 +1,113 @@ +module math + +const ( + tan_p = [ + -1.30936939181383777646e+4, + 1.15351664838587416140e+6, + -1.79565251976484877988e+7, + ] + tan_q = [ + 1.00000000000000000000e+0, + 1.36812963470692954678e+4, + -1.32089234440210967447e+6, + 2.50083801823357915839e+7, + -5.38695755929454629881e+7, + ] + tan_dp1 = 7.853981554508209228515625e-1 + tan_dp2 = 7.94662735614792836714e-9 + tan_dp3 = 3.06161699786838294307e-17 + tan_lossth = 1.073741824e+9 +) + +// tan calculates tangent of a number +pub fn tan(a f64) f64 { + mut x := a + if x == 0.0 || is_nan(x) { + return x + } + if is_inf(x, 0) { + return nan() + } + mut sign := 1 // make argument positive but save the sign + if x < 0 { + x = -x + sign = -1 + } + if x > math.tan_lossth { + return 0.0 + } + // compute x mod pi_4 + mut y := floor(x * 4.0 / pi) // strip high bits of integer part + mut z := ldexp(y, -3) + z = floor(z) // integer part of y/8 + z = y - ldexp(z, 3) // y - 16 * (y/16) // integer and fractional part modulo one octant + mut octant := int(z) // map zeros and singularities to origin + if (octant & 1) == 1 { + octant++ + y += 1.0 + } + z = ((x - y * math.tan_dp1) - y * math.tan_dp2) - y * math.tan_dp3 + zz := z * z + if zz > 1.0e-14 { + y = z + z * (zz * (((math.tan_p[0] * zz) + math.tan_p[1]) * zz + math.tan_p[2]) / ((((zz + + math.tan_q[1]) * zz + math.tan_q[2]) * zz + math.tan_q[3]) * zz + math.tan_q[4])) + } else { + y = z + } + if (octant & 2) == 2 { + y = -1.0 / y + } + if sign < 0 { + y = -y + } + return y +} + +// tanf calculates tangent. (float32) +[inline] +pub fn tanf(a f32) f32 { + return f32(tan(a)) +} + +// tan calculates cotangent of a number +pub fn cot(a f64) f64 { + mut x := a + if x == 0.0 { + return inf(1) + } + mut sign := 1 // make argument positive but save the sign + if x < 0 { + x = -x + sign = -1 + } + if x > math.tan_lossth { + return 0.0 + } + // compute x mod pi_4 + mut y := floor(x * 4.0 / pi) // strip high bits of integer part + mut z := ldexp(y, -3) + z = floor(z) // integer part of y/8 + z = y - ldexp(z, 3) // y - 16 * (y/16) // integer and fractional part modulo one octant + mut octant := int(z) // map zeros and singularities to origin + if (octant & 1) == 1 { + octant++ + y += 1.0 + } + z = ((x - y * math.tan_dp1) - y * math.tan_dp2) - y * math.tan_dp3 + zz := z * z + if zz > 1.0e-14 { + y = z + z * (zz * (((math.tan_p[0] * zz) + math.tan_p[1]) * zz + math.tan_p[2]) / ((((zz + + math.tan_q[1]) * zz + math.tan_q[2]) * zz + math.tan_q[3]) * zz + math.tan_q[4])) + } else { + y = z + } + if (octant & 2) == 2 { + y = -y + } else { + y = 1.0 / y + } + if sign < 0 { + y = -y + } + return y +} |