codekingpro/portable-devtools

1// Copyright 2018 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4 5package math_test6 7import (8	. "math"9	"testing"10)11 12// Inputs to test trig_reduce13var trigHuge = []float64{14	1 << 28,15	1 << 29,16	1 << 30,17	1 << 35,18	1 << 120,19	1 << 240,20	1 << 480,21	1234567891234567 << 180,22	1234567891234567 << 300,23	MaxFloat64,24}25 26// Results for trigHuge[i] calculated with https://github.com/robpike/ivy27// using 4096 bits of working precision.   Values requiring less than28// 102 decimal digits (1 << 120, 1 << 240, 1 << 480, 1234567891234567 << 180)29// were confirmed via https://keisan.casio.com/30var cosHuge = []float64{31	-0.16556897949057876,32	-0.94517382606089662,33	0.78670712294118812,34	-0.76466301249635305,35	-0.92587902285483787,36	0.93601042593353793,37	-0.28282777640193788,38	-0.14616431394103619,39	-0.79456058210671406,40	-0.99998768942655994,41}42 43var sinHuge = []float64{44	-0.98619821183697566,45	0.32656766301856334,46	-0.61732641504604217,47	-0.64443035102329113,48	0.37782010936075202,49	-0.35197227524865778,50	0.95917070894368716,51	0.98926032637023618,52	-0.60718488235646949,53	0.00496195478918406,54}55 56var tanHuge = []float64{57	5.95641897939639421,58	-0.34551069233430392,59	-0.78469661331920043,60	0.84276385870875983,61	-0.40806638884180424,62	-0.37603456702698076,63	-3.39135965054779932,64	-6.76813854009065030,65	0.76417695016604922,66	-0.00496201587444489,67}68 69// Check that trig values of huge angles return accurate results.70// This confirms that argument reduction works for very large values71// up to MaxFloat64.72func TestHugeCos(t *testing.T) {73	for i := 0; i < len(trigHuge); i++ {74		f1 := cosHuge[i]75		f2 := Cos(trigHuge[i])76		if !close(f1, f2) {77			t.Errorf("Cos(%g) = %g, want %g", trigHuge[i], f2, f1)78		}79		f3 := Cos(-trigHuge[i])80		if !close(f1, f3) {81			t.Errorf("Cos(%g) = %g, want %g", -trigHuge[i], f3, f1)82		}83	}84}85 86func TestHugeSin(t *testing.T) {87	for i := 0; i < len(trigHuge); i++ {88		f1 := sinHuge[i]89		f2 := Sin(trigHuge[i])90		if !close(f1, f2) {91			t.Errorf("Sin(%g) = %g, want %g", trigHuge[i], f2, f1)92		}93		f3 := Sin(-trigHuge[i])94		if !close(-f1, f3) {95			t.Errorf("Sin(%g) = %g, want %g", -trigHuge[i], f3, -f1)96		}97	}98}99 100func TestHugeSinCos(t *testing.T) {101	for i := 0; i < len(trigHuge); i++ {102		f1, g1 := sinHuge[i], cosHuge[i]103		f2, g2 := Sincos(trigHuge[i])104		if !close(f1, f2) || !close(g1, g2) {105			t.Errorf("Sincos(%g) = %g, %g, want %g, %g", trigHuge[i], f2, g2, f1, g1)106		}107		f3, g3 := Sincos(-trigHuge[i])108		if !close(-f1, f3) || !close(g1, g3) {109			t.Errorf("Sincos(%g) = %g, %g, want %g, %g", -trigHuge[i], f3, g3, -f1, g1)110		}111	}112}113 114func TestHugeTan(t *testing.T) {115	for i := 0; i < len(trigHuge); i++ {116		f1 := tanHuge[i]117		f2 := Tan(trigHuge[i])118		if !close(f1, f2) {119			t.Errorf("Tan(%g) = %g, want %g", trigHuge[i], f2, f1)120		}121		f3 := Tan(-trigHuge[i])122		if !close(-f1, f3) {123			t.Errorf("Tan(%g) = %g, want %g", -trigHuge[i], f3, -f1)124		}125	}126}127