func ExampleStellar() {
// Exercise, p. 119.
day1 := 7.
day5 := 27.
r2 := []float64{
sexa.NewRA(15, 3, 51.937).Rad(),
sexa.NewRA(15, 9, 57.327).Rad(),
sexa.NewRA(15, 15, 37.898).Rad(),
sexa.NewRA(15, 20, 50.632).Rad(),
sexa.NewRA(15, 25, 32.695).Rad(),
}
d2 := []float64{
sexa.NewAngle(true, 8, 57, 34.51).Rad(),
sexa.NewAngle(true, 9, 9, 03.88).Rad(),
sexa.NewAngle(true, 9, 17, 37.94).Rad(),
sexa.NewAngle(true, 9, 23, 16.25).Rad(),
sexa.NewAngle(true, 9, 26, 01.01).Rad(),
}
jd := julian.CalendarGregorianToJD(1996, 2, 17)
dt := jd - base.J2000
dy := dt / base.JulianYear
dc := dy / 100
fmt.Printf("%.2f years\n", dy)
fmt.Printf("%.4f century\n", dc)
pmr := -.649 // sec/cen
pmd := -1.91 // sec/cen
r1 := sexa.NewRA(15, 17, 0.421+pmr*dc).Rad()
// Careful with quick and dirty way of applying correction to seconds
// component before converting to radians. The dec here is negative
// so correction must be subtracted. Alternative, less error-prone,
// way would be to convert both to radians, then add.
d1 := sexa.NewAngle(true, 9, 22, 58.54-pmd*dc).Rad()
fmt.Printf("α′ = %.3d, δ′ = %.2d\n",
sexa.NewFmtRA(r1), sexa.NewFmtAngle(d1))
day, dd, err := conjunction.Stellar(day1, day5, r1, d1, r2, d2)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(sexa.NewFmtAngle(dd))
dInt, dFrac := math.Modf(day)
fmt.Printf("1996 February %d at %s TD\n", int(dInt),
sexa.NewFmtTime(dFrac*24*3600))
// Output:
// -3.87 years
// -0.0387 century
// α′ = 15ʰ17ᵐ0ˢ.446, δ′ = -9°22′58″.47
// 3′38″
// 1996 February 18 at 6ʰ36ᵐ55ˢ TD
}
func ExampleStellar() {
// Exercise, p. 119.
day1 := 7.
day5 := 27.
r2 := []unit.Angle{
unit.NewRA(15, 3, 51.937).Angle(),
unit.NewRA(15, 9, 57.327).Angle(),
unit.NewRA(15, 15, 37.898).Angle(),
unit.NewRA(15, 20, 50.632).Angle(),
unit.NewRA(15, 25, 32.695).Angle(),
}
d2 := []unit.Angle{
unit.NewAngle('-', 8, 57, 34.51),
unit.NewAngle('-', 9, 9, 03.88),
unit.NewAngle('-', 9, 17, 37.94),
unit.NewAngle('-', 9, 23, 16.25),
unit.NewAngle('-', 9, 26, 01.01),
}
jd := julian.CalendarGregorianToJD(1996, 2, 17)
dt := jd - base.J2000
dy := dt / base.JulianYear
dc := dy / 100
fmt.Printf("%.2f years\n", dy)
fmt.Printf("%.4f century\n", dc)
pmr := -.649 // sec/cen
pmd := -1.91 // sec/cen
r1 := unit.NewRA(15, 17, 0.421) + unit.RAFromSec(pmr*dc)
d1 := unit.NewAngle('-', 9, 22, 58.54) + unit.AngleFromSec(pmd*dc)
fmt.Printf("α′ = %.3d, δ′ = %.2d\n", sexa.FmtRA(r1), sexa.FmtAngle(d1))
day, dd, err := conjunction.Stellar(day1, day5, r1.Angle(), d1, r2, d2)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(sexa.FmtAngle(dd))
dInt, dFrac := math.Modf(day)
fmt.Printf("1996 February %d at %s TD\n", int(dInt),
sexa.FmtTime(unit.TimeFromDay(dFrac)))
// Output:
// -3.87 years
// -0.0387 century
// α′ = 15ʰ17ᵐ0ˢ.446, δ′ = -9°22′58″.47
// 3′38″
// 1996 February 18 at 6ʰ36ᵐ55ˢ TD
}