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Diffstat (limited to 'src/pkg/math/cmplx/sin.go')
| -rw-r--r-- | src/pkg/math/cmplx/sin.go | 132 |
1 files changed, 0 insertions, 132 deletions
diff --git a/src/pkg/math/cmplx/sin.go b/src/pkg/math/cmplx/sin.go deleted file mode 100644 index 2c57536ed..000000000 --- a/src/pkg/math/cmplx/sin.go +++ /dev/null @@ -1,132 +0,0 @@ -// Copyright 2010 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package cmplx - -import "math" - -// The original C code, the long comment, and the constants -// below are from http://netlib.sandia.gov/cephes/c9x-complex/clog.c. -// The go code is a simplified version of the original C. -// -// Cephes Math Library Release 2.8: June, 2000 -// Copyright 1984, 1987, 1989, 1992, 2000 by Stephen L. Moshier -// -// The readme file at http://netlib.sandia.gov/cephes/ says: -// Some software in this archive may be from the book _Methods and -// Programs for Mathematical Functions_ (Prentice-Hall or Simon & Schuster -// International, 1989) or from the Cephes Mathematical Library, a -// commercial product. In either event, it is copyrighted by the author. -// What you see here may be used freely but it comes with no support or -// guarantee. -// -// The two known misprints in the book are repaired here in the -// source listings for the gamma function and the incomplete beta -// integral. -// -// Stephen L. Moshier -// moshier@na-net.ornl.gov - -// Complex circular sine -// -// DESCRIPTION: -// -// If -// z = x + iy, -// -// then -// -// w = sin x cosh y + i cos x sinh y. -// -// csin(z) = -i csinh(iz). -// -// ACCURACY: -// -// Relative error: -// arithmetic domain # trials peak rms -// DEC -10,+10 8400 5.3e-17 1.3e-17 -// IEEE -10,+10 30000 3.8e-16 1.0e-16 -// Also tested by csin(casin(z)) = z. - -// Sin returns the sine of x. -func Sin(x complex128) complex128 { - s, c := math.Sincos(real(x)) - sh, ch := sinhcosh(imag(x)) - return complex(s*ch, c*sh) -} - -// Complex hyperbolic sine -// -// DESCRIPTION: -// -// csinh z = (cexp(z) - cexp(-z))/2 -// = sinh x * cos y + i cosh x * sin y . -// -// ACCURACY: -// -// Relative error: -// arithmetic domain # trials peak rms -// IEEE -10,+10 30000 3.1e-16 8.2e-17 - -// Sinh returns the hyperbolic sine of x. -func Sinh(x complex128) complex128 { - s, c := math.Sincos(imag(x)) - sh, ch := sinhcosh(real(x)) - return complex(c*sh, s*ch) -} - -// Complex circular cosine -// -// DESCRIPTION: -// -// If -// z = x + iy, -// -// then -// -// w = cos x cosh y - i sin x sinh y. -// -// ACCURACY: -// -// Relative error: -// arithmetic domain # trials peak rms -// DEC -10,+10 8400 4.5e-17 1.3e-17 -// IEEE -10,+10 30000 3.8e-16 1.0e-16 - -// Cos returns the cosine of x. -func Cos(x complex128) complex128 { - s, c := math.Sincos(real(x)) - sh, ch := sinhcosh(imag(x)) - return complex(c*ch, -s*sh) -} - -// Complex hyperbolic cosine -// -// DESCRIPTION: -// -// ccosh(z) = cosh x cos y + i sinh x sin y . -// -// ACCURACY: -// -// Relative error: -// arithmetic domain # trials peak rms -// IEEE -10,+10 30000 2.9e-16 8.1e-17 - -// Cosh returns the hyperbolic cosine of x. -func Cosh(x complex128) complex128 { - s, c := math.Sincos(imag(x)) - sh, ch := sinhcosh(real(x)) - return complex(c*ch, s*sh) -} - -// calculate sinh and cosh -func sinhcosh(x float64) (sh, ch float64) { - if math.Abs(x) <= 0.5 { - return math.Sinh(x), math.Cosh(x) - } - e := math.Exp(x) - ei := 0.5 / e - e *= 0.5 - return e - ei, e + ei -} |