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v/vlib/math/complex.v
2019-07-09 21:12:51 +02:00

167 lines
3.7 KiB
Go

// Copyright (c) 2019 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
struct Complex {
re f64
im f64
}
pub fn complex(re f64,im f64) Complex {
return Complex{re,im}
}
// To String method
pub fn (c Complex) str() string {
mut out := '$c.re'
out += if c.im >= 0 {
'+$c.im'
}
else {
'$c.im'
}
out += 'i'
return out
}
// Complex Absolute value
pub fn (c Complex) abs() f64 {
return C.hypot(c.re,c.im)
}
// Complex Angle
pub fn (c Complex) angle() f64 {
return atan2(c.im, c.re)
}
// Complex Addition c1 + c2
pub fn (c1 Complex) + (c2 Complex) Complex {
return Complex{c1.re+c2.re,c1.im+c2.im}
}
// Complex Substraction c1 - c2
pub fn (c1 Complex) - (c2 Complex) Complex {
return Complex{c1.re-c2.re,c1.im-c2.im}
}
// Complex Multiplication c1 * c2
// Currently Not Supported
// pub fn (c1 Complex) * (c2 Complex) Complex {
// return Complex{
// (c1.re * c2.re) + ((c1.im * c2.im) * -1),
// (c1.re * c2.im) + (c1.im * c2.re)
// }
// }
// Complex Division c1 / c2
// Currently Not Supported
// pub fn (c1 Complex) / (c2 Complex) Complex {
// denom := (c2.re * c2.re) + (c2.im * c2.im)
// return Complex {
// ((c1.re * c2.re) + ((c1.im * -c2.im) * -1))/denom,
// ((c1.re * -c2.im) + (c1.im * c2.re))/denom
// }
// }
// Complex Addition c1.add(c2)
pub fn (c1 Complex) add(c2 Complex) Complex {
return c1 + c2
}
// Complex Subtraction c1.subtract(c2)
pub fn (c1 Complex) subtract(c2 Complex) Complex {
return c1 - c2
}
// Complex Multiplication c1.multiply(c2)
pub fn (c1 Complex) multiply(c2 Complex) Complex {
return Complex{
(c1.re * c2.re) + ((c1.im * c2.im) * -1),
(c1.re * c2.im) + (c1.im * c2.re)
}
}
// Complex Division c1.divide(c2)
pub fn (c1 Complex) divide(c2 Complex) Complex {
denom := (c2.re * c2.re) + (c2.im * c2.im)
return Complex {
((c1.re * c2.re) + ((c1.im * -c2.im) * -1))/denom,
((c1.re * -c2.im) + (c1.im * c2.re))/denom
}
}
// Complex Conjugate
pub fn (c1 Complex) conjugate() Complex{
return Complex{c1.re,-c1.im}
}
// Complex Additive Inverse
// Based on
// http://tutorial.math.lamar.edu/Extras/ComplexPrimer/Arithmetic.aspx
pub fn (c1 Complex) addinv() Complex {
return Complex{-c1.re,-c1.im}
}
// Complex Multiplicative Inverse
// Based on
// http://tutorial.math.lamar.edu/Extras/ComplexPrimer/Arithmetic.aspx
pub fn (c1 Complex) mulinv() Complex {
return Complex {
c1.re / (pow(c1.re,2) + pow(c1.im,2)),
-c1.im / (pow(c1.re,2) + pow(c1.im,2))
}
}
// Complex Mod or Absolute
// Based on
// http://tutorial.math.lamar.edu/Extras/ComplexPrimer/ConjugateModulus.aspx
pub fn (c1 Complex) mod() f64 {
return sqrt(pow(c1.re,2)+pow(c1.im,2))
}
// Complex Power
// Based on
// https://www.khanacademy.org/math/precalculus/imaginary-and-complex-numbers/multiplying-and-dividing-complex-numbers-in-polar-form/a/complex-number-polar-form-review
pub fn (c1 Complex) pow(n f64) Complex {
r := pow(c1.mod(),n)
angle := atan2(c1.im,c1.re)
return Complex {
r * cos(n*angle),
r * sin(n*angle)
}
}
// Complex nth root
pub fn (c1 Complex) root(n f64) Complex {
return c1.pow(1.0/n)
}
// Complex Exponential
// Using Euler's Identity
// Based on
// https://www.math.wisc.edu/~angenent/Free-Lecture-Notes/freecomplexnumbers.pdf
pub fn (c1 Complex) exp() Complex {
a := exp(c1.re)
return Complex {
a * cos(c1.im),
a * sin(c1.im)
}
}
// Complex Natural Logarithm
// Based on
// http://www.chemistrylearning.com/logarithm-of-complex-number/
pub fn (c1 Complex) ln() Complex {
return Complex {
log(c1.mod()),
atan2(c1.im,c1.re)
}
}
// Complex Equals
pub fn (c1 Complex) equals(c2 Complex) bool {
return (c1.re == c2.re) && (c1.im == c2.im)
}