func ExampleLen3_Zero() {
// Example 3.c, p. 26.
x1 := 26.
x3 := 28.
// the y unit doesn't matter. working in degrees is fine
yTable := []float64{
unit.FromSexa('-', 0, 28, 13.4),
unit.FromSexa(' ', 0, 6, 46.3),
unit.FromSexa(' ', 0, 38, 23.2),
}
d3, err := interp.NewLen3(x1, x3, yTable)
if err != nil {
fmt.Println(err)
return
}
x, err := d3.Zero(false)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("February %.5f\n", x)
i, frac := math.Modf(x)
fmt.Printf("February %d, at %m TD",
int(i), sexa.FmtTime(unit.TimeFromDay(frac)))
// Output:
// February 26.79873
// February 26, at 19ʰ10ᵐ TD
}
func ExampleLen4Half() {
// Example 3.f, p. 32.
half, err := interp.Len4Half([]float64{
unit.FromSexa(0, 10, 18, 48.732),
unit.FromSexa(0, 10, 23, 22.835),
unit.FromSexa(0, 10, 27, 57.247),
unit.FromSexa(0, 10, 32, 31.983),
})
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("%.3d", sexa.FmtRA(unit.RAFromHour(half)))
// Output:
// 10ʰ25ᵐ40ˢ.001
}
func ExampleLen5_Zero() {
// Exercise, p. 30.
x1 := 25.
x5 := 29.
yTable := []float64{
unit.FromSexa('-', 1, 11, 21.23),
unit.FromSexa('-', 0, 28, 12.31),
unit.FromSexa(' ', 0, 16, 07.02),
unit.FromSexa(' ', 1, 01, 00.13),
unit.FromSexa(' ', 1, 45, 46.33),
}
d5, err := interp.NewLen5(x1, x5, yTable)
if err != nil {
fmt.Println(err)
return
}
z, err := d5.Zero(false)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("1988 January %.6f\n", z)
zInt, zFrac := math.Modf(z)
fmt.Printf("1988 January %d at %m TD\n", int(zInt),
sexa.FmtTime(unit.TimeFromDay(zFrac)))
// compare result to that from just three central values
d3, err := interp.NewLen3(26, 28, yTable[1:4])
if err != nil {
fmt.Println(err)
return
}
z3, err := d3.Zero(false)
if err != nil {
fmt.Println(err)
return
}
dz := z - z3
fmt.Printf("%.6f day\n", dz)
fmt.Printf("%.1f minute\n", dz*24*60)
// Output:
// 1988 January 26.638587
// 1988 January 26 at 15ʰ20ᵐ TD
// 0.000753 day
// 1.1 minute
}
func Example_rA() {
// Example 1.a, p. 8
h := unit.FromSexa(' ', 9, 14, 55.8)
fmt.Printf("%.9f\n", h)
α := unit.RAFromHour(h)
fmt.Printf("%.5f\n", α.Deg())
fmt.Printf("%.6f\n", α.Tan())
// Output:
// 9.248833333
// 138.73250
// -0.877517
}
func ExampleLen5_InterpolateX() {
// Example 3.e, p. 28.
x1 := 27.
x5 := 29.
// work in degrees
yTable := []float64{
unit.FromSexa(' ', 0, 54, 36.125),
unit.FromSexa(' ', 0, 54, 24.606),
unit.FromSexa(' ', 0, 54, 15.486),
unit.FromSexa(' ', 0, 54, 08.694),
unit.FromSexa(' ', 0, 54, 04.133),
}
d5, err := interp.NewLen5(x1, x5, yTable)
if err != nil {
fmt.Println(err)
return
}
n := (3 + 20./60) / 24
x := 28 + n
y := d5.InterpolateX(x)
fmt.Printf("%.3d", sexa.FmtAngle(unit.AngleFromDeg(y)))
// Output:
// 54′13″.369
}
func ExampleLen3_InterpolateN() {
// Example 3.a, p. 25.
d3, err := interp.NewLen3(7, 9, []float64{
.884226,
.877366,
.870531,
})
if err != nil {
fmt.Println(err)
return
}
h := unit.FromSexa(0, 4, 21, 0)
fmt.Println(h, "hours")
n := h / 24
y := d3.InterpolateN(n)
fmt.Printf("%.6f\n", y)
// Output:
// 4.35 hours
// 0.876125
}