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+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module math
+
+// aprox_sin returns an approximation of sin(a) made using lolremez
+pub fn aprox_sin(a f64) f64 {
+ a0 := 1.91059300966915117e-31
+ a1 := 1.00086760103908896
+ a2 := -1.21276126894734565e-2
+ a3 := -1.38078780785773762e-1
+ a4 := -2.67353392911981221e-2
+ a5 := 2.08026600266304389e-2
+ a6 := -3.03996055049204407e-3
+ a7 := 1.38235642404333740e-4
+ return a0 + a * (a1 + a * (a2 + a * (a3 + a * (a4 + a * (a5 + a * (a6 + a * a7))))))
+}
+
+// aprox_cos returns an approximation of sin(a) made using lolremez
+pub fn aprox_cos(a f64) f64 {
+ a0 := 9.9995999154986614e-1
+ a1 := 1.2548995793001028e-3
+ a2 := -5.0648546280678015e-1
+ a3 := 1.2942246466519995e-2
+ a4 := 2.8668384702547972e-2
+ a5 := 7.3726485210586547e-3
+ a6 := -3.8510875386947414e-3
+ a7 := 4.7196604604366623e-4
+ a8 := -1.8776444013090451e-5
+ return a0 + a * (a1 + a * (a2 + a * (a3 + a * (a4 + a * (a5 + a * (a6 + a * (a7 + a * a8)))))))
+}
+
+// copysign returns a value with the magnitude of x and the sign of y
+[inline]
+pub fn copysign(x f64, y f64) f64 {
+ return f64_from_bits((f64_bits(x) & ~sign_mask) | (f64_bits(y) & sign_mask))
+}
+
+// degrees convert from degrees to radians.
+[inline]
+pub fn degrees(radians f64) f64 {
+ return radians * (180.0 / pi)
+}
+
+// digits returns an array of the digits of n in the given base.
+pub fn digits(_n int, base int) []int {
+ if base < 2 {
+ panic('digits: Cannot find digits of n with base $base')
+ }
+ mut n := _n
+ mut sign := 1
+ if n < 0 {
+ sign = -1
+ n = -n
+ }
+ mut res := []int{}
+ for n != 0 {
+ res << (n % base) * sign
+ n /= base
+ }
+ return res
+}
+
+// max returns the maximum value of the two provided.
+[inline]
+pub fn max(a f64, b f64) f64 {
+ if a > b {
+ return a
+ }
+ return b
+}
+
+// min returns the minimum value of the two provided.
+[inline]
+pub fn min(a f64, b f64) f64 {
+ if a < b {
+ return a
+ }
+ return b
+}
+
+// minmax returns the minimum and maximum value of the two provided.
+pub fn minmax(a f64, b f64) (f64, f64) {
+ if a < b {
+ return a, b
+ }
+ return b, a
+}
+
+// sign returns the corresponding sign -1.0, 1.0 of the provided number.
+// if n is not a number, its sign is nan too.
+[inline]
+pub fn sign(n f64) f64 {
+ if is_nan(n) {
+ return nan()
+ }
+ return copysign(1.0, n)
+}
+
+// signi returns the corresponding sign -1.0, 1.0 of the provided number.
+[inline]
+pub fn signi(n f64) int {
+ return int(copysign(1.0, n))
+}
+
+// radians convert from radians to degrees.
+[inline]
+pub fn radians(degrees f64) f64 {
+ return degrees * (pi / 180.0)
+}
+
+// signbit returns a value with the boolean representation of the sign for x
+[inline]
+pub fn signbit(x f64) bool {
+ return f64_bits(x) & sign_mask != 0
+}
+
+pub fn tolerance(a f64, b f64, tol f64) bool {
+ mut ee := tol
+ // Multiplying by ee here can underflow denormal values to zero.
+ // Check a==b so that at least if a and b are small and identical
+ // we say they match.
+ if a == b {
+ return true
+ }
+ mut d := a - b
+ if d < 0 {
+ d = -d
+ }
+ // note: b is correct (expected) value, a is actual value.
+ // make error tolerance a fraction of b, not a.
+ if b != 0 {
+ ee = ee * b
+ if ee < 0 {
+ ee = -ee
+ }
+ }
+ return d < ee
+}
+
+pub fn close(a f64, b f64) bool {
+ return tolerance(a, b, 1e-14)
+}
+
+pub fn veryclose(a f64, b f64) bool {
+ return tolerance(a, b, 4e-16)
+}
+
+pub fn alike(a f64, b f64) bool {
+ if is_nan(a) && is_nan(b) {
+ return true
+ } else if a == b {
+ return signbit(a) == signbit(b)
+ }
+ return false
+}
+
+fn is_odd_int(x f64) bool {
+ xi, xf := modf(x)
+ return xf == 0 && (i64(xi) & 1) == 1
+}
+
+fn is_neg_int(x f64) bool {
+ if x < 0 {
+ _, xf := modf(x)
+ return xf == 0
+ }
+ return false
+}