51 lines
894 B
Scheme
51 lines
894 B
Scheme
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;;
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;; math.ss: some extra math routines
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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(module math mzscheme
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(provide e
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pi
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sqr
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sgn conjugate
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sinh cosh)
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(define (sqr z) (* z z))
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;; circular constants and aliases
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(define e (exp 1.0))
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(define pi (atan 0 -1))
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;; sgn function
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(define sgn
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(lambda (x)
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(if (exact? x)
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(cond
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((< x 0) -1)
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((> x 0) 1)
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(else 0))
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(cond
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((< x 0.0) -1.0)
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((> x 0.0) 1.0)
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(else 0.0)))))
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;; complex conjugate
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(define conjugate
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(lambda (z)
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(make-rectangular
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(real-part z)
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(- (imag-part z)))))
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;; real hyperbolic functions
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(define sinh
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(lambda (x)
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(/
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(- (exp x) (exp (- x)))
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2.0)))
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(define cosh
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(lambda (x)
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(/
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(+ (exp x) (exp (- x)))
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2.0))))
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