func ExampleTimes() {
// Example 15.a, p. 103.
// Venus on 1988 March 20
p := globe.Coord{
Lon: unit.NewAngle(' ', 71, 5, 0),
Lat: unit.NewAngle(' ', 42, 20, 0),
}
Th0 := unit.NewTime(' ', 11, 50, 58.1)
α3 := []unit.RA{
unit.NewRA(2, 42, 43.25),
unit.NewRA(2, 46, 55.51),
unit.NewRA(2, 51, 07.69),
}
δ3 := []unit.Angle{
unit.NewAngle(' ', 18, 02, 51.4),
unit.NewAngle(' ', 18, 26, 27.3),
unit.NewAngle(' ', 18, 49, 38.7),
}
h0 := unit.AngleFromDeg(-.5667)
ΔT := unit.Time(56)
tRise, tTransit, tSet, err := rise.Times(p, ΔT, h0, Th0, α3, δ3)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("rising: %+.5f %02s\n", tRise/86400, sexa.FmtTime(tRise))
fmt.Printf("transit: %+.5f %02s\n", tTransit/86400, sexa.FmtTime(tTransit))
fmt.Printf("seting: %+.5f %02s\n", tSet/86400, sexa.FmtTime(tSet))
// Output:
// rising: +0.51766 12ʰ25ᵐ26ˢ
// transit: +0.81980 19ʰ40ᵐ30ˢ
// seting: +0.12130 02ʰ54ᵐ40ˢ
}
func ExampleApproxTimes() {
// Example 15.a, p. 103.
// Venus on 1988 March 20
p := globe.Coord{
Lon: unit.NewAngle(' ', 71, 5, 0),
Lat: unit.NewAngle(' ', 42, 20, 0),
}
Th0 := unit.NewTime(' ', 11, 50, 58.1)
α := unit.NewRA(2, 46, 55.51)
δ := unit.NewAngle(' ', 18, 26, 27.3)
h0 := rise.Stdh0Stellar
tRise, tTransit, tSet, err := rise.ApproxTimes(p, h0, Th0, α, δ)
if err != nil {
fmt.Println(err)
return
}
// Units for "m" values given near top of p. 104 are day fraction.
fmt.Printf("rising: %+.5f %02s\n", tRise/86400, sexa.FmtTime(tRise))
fmt.Printf("transit: %+.5f %02s\n", tTransit/86400, sexa.FmtTime(tTransit))
fmt.Printf("seting: %+.5f %02s\n", tSet/86400, sexa.FmtTime(tSet))
// Output:
// rising: +0.51816 12ʰ26ᵐ09ˢ
// transit: +0.81965 19ʰ40ᵐ17ˢ
// seting: +0.12113 02ʰ54ᵐ26ˢ
}
func Test2000(t *testing.T) {
for i := range mar {
e := &mar[i]
approx := solstice.March(e.y)
vsop87 := julian.CalendarGregorianToJD(e.y, 3, e.d) +
unit.NewTime(' ', e.h, e.m, e.s).Day()
if math.Abs(vsop87-approx) > 1./24/60 {
t.Logf("mar %d: got %.5f expected %.5f", e.y, approx, vsop87)
t.Errorf("%.0f second error", math.Abs(vsop87-approx)*24*60*60)
}
}
for i := range jun {
e := &jun[i]
approx := solstice.June(e.y)
vsop87 := julian.CalendarGregorianToJD(e.y, 6, e.d) +
unit.NewTime(' ', e.h, e.m, e.s).Day()
if math.Abs(vsop87-approx) > 1./24/60 {
t.Logf("jun %d: got %.5f expected %.5f", e.y, approx, vsop87)
t.Errorf("%.0f second error", math.Abs(vsop87-approx)*24*60*60)
}
}
for i := range sep {
e := &sep[i]
approx := solstice.September(e.y)
vsop87 := julian.CalendarGregorianToJD(e.y, 9, e.d) +
unit.NewTime(' ', e.h, e.m, e.s).Day()
if math.Abs(vsop87-approx) > 1./24/60 {
t.Logf("sep %d: got %.5f expected %.5f", e.y, approx, vsop87)
t.Errorf("%.0f day error", math.Abs(vsop87-approx))
}
}
for i := range dec {
e := &dec[i]
approx := solstice.December(e.y)
vsop87 := julian.CalendarGregorianToJD(e.y, 12, e.d) +
unit.NewTime(' ', e.h, e.m, e.s).Day()
if math.Abs(vsop87-approx) > 1./24/60 {
t.Logf("dec %d: got %.5f expected %.5f", e.y, approx, vsop87)
t.Errorf("%.0f second error", math.Abs(vsop87-approx)*24*60*60)
}
}
}
func ExampleTopocentric2() {
// Example 40.a, p. 280
Δα, Δδ := parallax.Topocentric2(
unit.RAFromDeg(339.530208),
unit.AngleFromDeg(-15.771083),
.37276, .546861, .836339,
unit.Angle(unit.NewHourAngle(' ', 7, 47, 27)),
julian.CalendarGregorianToJD(2003, 8, 28+
unit.NewTime(' ', 3, 17, 0).Day()))
fmt.Printf("Δα = %.2s (sec of RA)\n", sexa.FmtHourAngle(Δα))
fmt.Printf("Δδ = %.1s (sec of Dec)\n", sexa.FmtAngle(Δδ))
// Output:
// Δα = 1.29ˢ (sec of RA)
// Δδ = -14.1″ (sec of Dec)
}
func ExampleTopocentric() {
// Example 40.a, p. 280
α, δ := parallax.Topocentric(
unit.RAFromDeg(339.530208),
unit.AngleFromDeg(-15.771083),
.37276, .546861, .836339,
unit.Angle(unit.NewHourAngle(' ', 7, 47, 27)),
julian.CalendarGregorianToJD(2003, 8, 28+
unit.NewTime(' ', 3, 17, 0).Day()))
fmt.Printf("α' = %.2d\n", sexa.FmtRA(α))
fmt.Printf("δ' = %.1d\n", sexa.FmtAngle(δ))
// Output:
// α' = 22ʰ38ᵐ8ˢ.54
// δ' = -15°46′30″.0
}
func ExampleLen3_InterpolateX() {
// Example 3.a, p. 25.
d3, err := interp.NewLen3(7, 9, []float64{
.884226,
.877366,
.870531,
})
if err != nil {
fmt.Println(err)
return
}
x := 8 + unit.NewTime(' ', 4, 21, 0).Day() // 8th day at 4:21
y := d3.InterpolateX(x)
fmt.Printf("%.6f\n", y)
// Output:
// 0.876125
}
func ExampleTopocentric3() {
// same test case as example 40.a, p. 280
α := unit.RAFromDeg(339.530208)
δ := unit.AngleFromDeg(-15.771083)
Δ := .37276
ρsφʹ := .546861
ρcφʹ := .836339
L := unit.Angle(unit.NewHourAngle(' ', 7, 47, 27))
jde := julian.CalendarGregorianToJD(2003, 8, 28+
unit.NewTime(' ', 3, 17, 0).Day())
Hʹ, δʹ := parallax.Topocentric3(α, δ, Δ, ρsφʹ, ρcφʹ, L, jde)
fmt.Printf("Hʹ = %.2d\n", sexa.FmtHourAngle(Hʹ))
θ0 := sidereal.Apparent(jde)
αʹ := unit.RAFromRad(θ0.Rad() - L.Rad() - Hʹ.Rad())
// same result as example 40.a, p. 280
fmt.Printf("αʹ = %.2d\n", sexa.FmtRA(αʹ))
fmt.Printf("δʹ = %.1d\n", sexa.FmtAngle(δʹ))
// Output:
// Hʹ = -4ʰ44ᵐ50ˢ.28
// αʹ = 22ʰ38ᵐ8ˢ.54
// δʹ = -15°46′30″.0
}