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Diffstat (limited to 'v_windows/v/vlib/math/sin.v')
| -rw-r--r-- | v_windows/v/vlib/math/sin.v | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/v_windows/v/vlib/math/sin.v b/v_windows/v/vlib/math/sin.v new file mode 100644 index 0000000..193eb79 --- /dev/null +++ b/v_windows/v/vlib/math/sin.v @@ -0,0 +1,179 @@ +module math + +import math.internal + +const ( + sin_data = [ + -0.3295190160663511504173, + 0.0025374284671667991990, + 0.0006261928782647355874, + -4.6495547521854042157541e-06, + -5.6917531549379706526677e-07, + 3.7283335140973803627866e-09, + 3.0267376484747473727186e-10, + -1.7400875016436622322022e-12, + -1.0554678305790849834462e-13, + 5.3701981409132410797062e-16, + 2.5984137983099020336115e-17, + -1.1821555255364833468288e-19, + ] + sin_cs = ChebSeries{ + c: sin_data + order: 11 + a: -1 + b: 1 + } + cos_data = [ + 0.165391825637921473505668118136, + -0.00084852883845000173671196530195, + -0.000210086507222940730213625768083, + 1.16582269619760204299639757584e-6, + 1.43319375856259870334412701165e-7, + -7.4770883429007141617951330184e-10, + -6.0969994944584252706997438007e-11, + 2.90748249201909353949854872638e-13, + 1.77126739876261435667156490461e-14, + -7.6896421502815579078577263149e-17, + -3.7363121133079412079201377318e-18, + ] + cos_cs = ChebSeries{ + c: cos_data + order: 10 + a: -1 + b: 1 + } +) + +pub fn sin(x f64) f64 { + p1 := 7.85398125648498535156e-1 + p2 := 3.77489470793079817668e-8 + p3 := 2.69515142907905952645e-15 + sgn_x := if x < 0 { -1 } else { 1 } + abs_x := abs(x) + if abs_x < internal.root4_f64_epsilon { + x2 := x * x + return x * (1.0 - x2 / 6.0) + } else { + mut sgn_result := sgn_x + mut y := floor(abs_x / (0.25 * pi)) + mut octant := int(y - ldexp(floor(ldexp(y, -3)), 3)) + if (octant & 1) == 1 { + octant++ + octant &= 7 + y += 1.0 + } + if octant > 3 { + octant -= 4 + sgn_result = -sgn_result + } + z := ((abs_x - y * p1) - y * p2) - y * p3 + mut result := 0.0 + if octant == 0 { + t := 8.0 * abs(z) / pi - 1.0 + sin_cs_val, _ := math.sin_cs.eval_e(t) + result = z * (1.0 + z * z * sin_cs_val) + } else { + t := 8.0 * abs(z) / pi - 1.0 + cos_cs_val, _ := math.cos_cs.eval_e(t) + result = 1.0 - 0.5 * z * z * (1.0 - z * z * cos_cs_val) + } + result *= sgn_result + return result + } +} + +pub fn cos(x f64) f64 { + p1 := 7.85398125648498535156e-1 + p2 := 3.77489470793079817668e-8 + p3 := 2.69515142907905952645e-15 + abs_x := abs(x) + if abs_x < internal.root4_f64_epsilon { + x2 := x * x + return 1.0 - 0.5 * x2 + } else { + mut sgn_result := 1 + mut y := floor(abs_x / (0.25 * pi)) + mut octant := int(y - ldexp(floor(ldexp(y, -3)), 3)) + if (octant & 1) == 1 { + octant++ + octant &= 7 + y += 1.0 + } + if octant > 3 { + octant -= 4 + sgn_result = -sgn_result + } + if octant > 1 { + sgn_result = -sgn_result + } + z := ((abs_x - y * p1) - y * p2) - y * p3 + mut result := 0.0 + if octant == 0 { + t := 8.0 * abs(z) / pi - 1.0 + cos_cs_val, _ := math.cos_cs.eval_e(t) + result = 1.0 - 0.5 * z * z * (1.0 - z * z * cos_cs_val) + } else { + t := 8.0 * abs(z) / pi - 1.0 + sin_cs_val, _ := math.sin_cs.eval_e(t) + result = z * (1.0 + z * z * sin_cs_val) + } + result *= sgn_result + return result + } +} + +// cosf calculates cosine. (float32). +[inline] +pub fn cosf(a f32) f32 { + return f32(cos(a)) +} + +// sinf calculates sine. (float32) +[inline] +pub fn sinf(a f32) f32 { + return f32(sin(a)) +} + +pub fn sincos(x f64) (f64, f64) { + p1 := 7.85398125648498535156e-1 + p2 := 3.77489470793079817668e-8 + p3 := 2.69515142907905952645e-15 + sgn_x := if x < 0 { -1 } else { 1 } + abs_x := abs(x) + if abs_x < internal.root4_f64_epsilon { + x2 := x * x + return x * (1.0 - x2 / 6.0), 1.0 - 0.5 * x2 + } else { + mut sgn_result_sin := sgn_x + mut sgn_result_cos := 1 + mut y := floor(abs_x / (0.25 * pi)) + mut octant := int(y - ldexp(floor(ldexp(y, -3)), 3)) + if (octant & 1) == 1 { + octant++ + octant &= 7 + y += 1.0 + } + if octant > 3 { + octant -= 4 + sgn_result_sin = -sgn_result_sin + sgn_result_cos = -sgn_result_cos + } + sgn_result_cos = if octant > 1 { -sgn_result_cos } else { sgn_result_cos } + z := ((abs_x - y * p1) - y * p2) - y * p3 + t := 8.0 * abs(z) / pi - 1.0 + sin_cs_val, _ := math.sin_cs.eval_e(t) + cos_cs_val, _ := math.cos_cs.eval_e(t) + mut result_sin := 0.0 + mut result_cos := 0.0 + if octant == 0 { + result_sin = z * (1.0 + z * z * sin_cs_val) + result_cos = 1.0 - 0.5 * z * z * (1.0 - z * z * cos_cs_val) + } else { + result_sin = 1.0 - 0.5 * z * z * (1.0 - z * z * cos_cs_val) + result_cos = z * (1.0 + z * z * sin_cs_val) + } + result_sin *= sgn_result_sin + result_cos *= sgn_result_cos + return result_sin, result_cos + } +} |