# Horoscope object (/en/docs/go/horoscope) The data structures of the six scopes, plus palace lookups that need not be handed the astrolabe again. A horoscope projects the natal chart onto a point in time. The same chart shows a different palace layout in different years — which is exactly what "the decadal scope has moved to that palace" means. ```go h, _ := chart.Horoscope("2025-6-1", 0) ``` `Horoscope` holds the natal chart that produced it, so none of the query methods need the astrolabe passed in again. The examples on this page start from an `"en-US"` natal chart, so the display values in the output are English. ## Fields [#fields] | Field | Type | Span | Description | | ------------------------- | ---------------- | --------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SolarDate` / `LunarDate` | `string` | — | The solar string and the Chinese lunar spelling of the **target** date. The birth date lives on the natal chart; read it from `h.Astrolabe().SolarDate` | | `Decadal` | `HoroscopeScope` | Ten years | The decadal scope; the childhood scope for the years before it begins | | `Age` | `HoroscopeScope` | One year | The age scope, moving one palace per nominal year | | `Yearly` | `HoroscopeScope` | One year | The yearly scope, its palace fixed by the year's pillar | | `Monthly` | `HoroscopeScope` | One month | The monthly scope | | `Daily` | `HoroscopeScope` | One day | The daily scope | | `Hourly` | `HoroscopeScope` | One double-hour | The hourly scope | Both advance once per year, but they start differently: the age scope starts from the birth-year branch and steps forward with the nominal age, while the yearly scope simply asks which palace that year's pillar falls in. The two lines are independent, and Zi Wei practice usually reads them together. ### HoroscopeScope [#horoscopescope] | Field | Type | Description | | ------------------------------------ | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `Index` | `int` | Which palace this scope lands on (a palace index) | | `Name` | `string` | Display name of the scope, translated into the output language | | `NameKey` | `string` | Scope key: `decadal` / `childhood` (before the decadals begin) / `turn` (age fortune) / `yearly` / `monthly` / `daily` / `hourly`. Predicate on this, never on the translation | | `HeavenlyStem` / `HeavenlyStemKey` | `string` | Stem of the scope, which determines the mutagens it flies | | `EarthlyBranch` / `EarthlyBranchKey` | `string` | Branch of the scope | | `PalaceNames` / `PalaceNameKeys` | `[]string` | The twelve palace names re-derived with this scope's palace as the Soul palace, indexed by palace index | | `Mutagen` / `MutagenStarKeys` | `[]string` | The stars this scope's stem transforms, in the order lu, quan, ke, ji; `MutagenStarKeys` holds the mutated stars' star keys, synonymous with the palace field of the same name | | `Stars` | `[][]Star` | The scope stars of this layer; `nil` for layers that have none | | `NominalAge` | `int` | Age scope only: the nominal age. `0` on every other layer | | `YearlyDecStar` | `*YearlyDecStar` | Yearly scope only: the Sui-qian and Jiang-qian gods. **`nil`** on every other layer | ```go type YearlyDecStar struct { Suiqian12 []string `json:"suiqian12"` // Sui-qian gods, translated, by palace index Suiqian12Keys []string `json:"suiqian12Keys"` // their keys Jiangqian12 []string `json:"jiangqian12"` // Jiang-qian gods, translated Jiangqian12Keys []string `json:"jiangqian12Keys"` // their keys } ``` Rather than giving the age and yearly scopes types of their own, the Go side puts `NominalAge` and `YearlyDecStar` into the shared `HoroscopeScope`, where the other layers leave them at their zero values. Call sites can therefore write generic logic parameterized by scope. `h.Decadal.YearlyDecStar` is `nil`, and reading a field on it panics. Only `h.Yearly.YearlyDecStar` is non-nil — check before you walk the layers. ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.Decadal.YearlyDecStar == nil, h.Yearly.YearlyDecStar != nil) fmt.Println(h.Yearly.YearlyDecStar.Suiqian12[:3]) fmt.Println(h.Yearly.YearlyDecStar.Jiangqian12Keys[:3]) fmt.Println(h.Decadal.NominalAge, h.Age.NominalAge) ``` **Output** ```text true true [blessed sorrowing illness] [jiesha zhaisha tiansha] 0 26 ``` ### PalaceIndexByName [#palaceindexbyname] ```go func (item *HoroscopeScope) PalaceIndexByName(nameKeyOrName string) int ``` Looks a palace index up by palace-name key, or by palace name in the current language, among the twelve palaces as re-derived for that scope; **returns -1 when nothing matches**. ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.Decadal.PalaceIndexByName(iztro.PalaceSoul)) fmt.Println(h.Decadal.PalaceIndexByName(iztro.PalaceWealth)) fmt.Println(h.Decadal.PalaceIndexByName("nosuch")) ``` **Output** ```text 2 10 -1 ``` It returns `-1` rather than `0` — `0` is a legitimate palace index (the Yin palace). Always check for a negative before indexing `chart.Palaces` with it. **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) for _, item := range []iztro.HoroscopeScope{h.Decadal, h.Monthly, h.Daily, h.Hourly} { fmt.Printf("%s lands on palace %d with pillar %s%s\n", item.Name, item.Index, item.HeavenlyStem, item.EarthlyBranch) } fmt.Println("age scope nominal age", h.Age.NominalAge) fmt.Println("decadal mutagens", h.Decadal.Mutagen) fmt.Println("yearly Sui-qian gods", h.Yearly.YearlyDecStar.Suiqian12[:3]) ``` **Output** ```text decadal lands on palace 2 with pillar gengchen monthly lands on palace 3 with pillar renwoo daily lands on palace 8 with pillar xinchou hourly lands on palace 8 with pillar wuzi age scope nominal age 26 decadal mutagens [sun general moon fortunate] yearly Sui-qian gods [blessed sorrowing illness] ``` *** ## AgePalace [#agepalace] **Purpose** Get the palace the age scope occupies this year. **Zi Wei meaning** The age scope is a line advancing year by year; whichever palace it lands on becomes the focus for that year. **Signature** ```go func (h *Horoscope) AgePalace() *Palace ``` **Return value** `*Palace` — a palace on the natal chart. **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.AgePalace().Name) ``` **Output** ```text property ``` *** ## Palace [#palace] **Purpose** Get one of the twelve palaces as re-derived under a given horoscope scope. **Zi Wei meaning** Once the decadal scope reaches a palace, the twelve palaces are re-anchored with that palace as the "decadal Soul palace". "The decadal Spouse palace" refers to that re-anchored naming, and it is usually not the same palace as the natal Spouse palace. **Signature** ```go func (h *Horoscope) Palace(nameKeyOrName string, scope string) *Palace ``` **Parameters** | Parameter | Type | Required | Default | Description | | --------------- | -------- | -------- | ------- | ----------------------------------------------- | | `nameKeyOrName` | `string` | Yes | — | The palace-name key or translated name to fetch | | `scope` | `string` | Yes | — | Which scope's twelve palaces to search | **Return value** `*Palace` — a palace on the natal chart (the same cell carries different names under different scopes). With `ScopeOrigin`, these are the natal twelve palaces. `nil` when nothing matches. **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println("the decadal Soul palace is the natal", h.Palace(iztro.PalaceSoul, iztro.ScopeDecadal).Name) fmt.Println("the natal Soul palace is", h.Palace(iztro.PalaceSoul, iztro.ScopeOrigin).Name) ``` **Output** ```text the decadal Soul palace is the natal spouse the natal Soul palace is soul ``` **Edge cases and pitfalls** On the returned palace object, `Name` is still the **natal palace name** (spouse in the example), because it is that cell on the natal chart. To see what the cell is called at the decadal layer, read `h.Decadal.PalaceNames[index]`. *** ## SurroundPalaces [#surroundpalaces] **Purpose** Get the surrounded palaces of a palace under a given horoscope scope. **Signature** ```go func (h *Horoscope) SurroundPalaces(nameKeyOrName string, scope string) *SurroundedPalaces ``` **Parameters** Same as `Palace`. **Return value** `*SurroundedPalaces`; its predicates are on [Surrounded palaces](/en/docs/go/surpalaces). **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) sp := h.SurroundPalaces(iztro.PalaceWealth, iztro.ScopeYearly) fmt.Println("the surrounded set of the yearly Wealth palace is anchored on the natal", sp.Target.Name) ``` **Output** ```text the surrounded set of the yearly Wealth palace is anchored on the natal health ``` *** ## HasHoroscopeStars / HasOneOfHoroscopeStars / NotHaveHoroscopeStars [#hashoroscopestars--hasoneofhoroscopestars--nothavehoroscopestars] **Purpose** Test whether a palace under a given scope holds the given scope stars. **Zi Wei meaning** Scope stars are a group produced by each horoscope layer: Tiankui, Tianyue, Wenchang, Wenqu, Lucun, Qingyang, Tuoluo, Tianma, Hongluan and Tianxi. They carry different names in different layers — Yunkui and Yunyue at the decadal layer, Liukui and Liuyue at the yearly layer — with the same meaning applied to their own time span. **Signature** ```go func (h *Horoscope) HasHoroscopeStars(nameKeyOrName string, scope string, stars []string) bool func (h *Horoscope) HasOneOfHoroscopeStars(nameKeyOrName string, scope string, stars []string) bool func (h *Horoscope) NotHaveHoroscopeStars(nameKeyOrName string, scope string, stars []string) bool ``` **Parameters** | Parameter | Type | Required | Default | Description | | --------------- | ---------- | -------- | ------- | ------------------------------------------------------------- | | `nameKeyOrName` | `string` | Yes | — | The palace name under that scope | | `scope` | `string` | Yes | — | The horoscope scope | | `stars` | `[]string` | Yes | — | A slice of scope star keys, which must use that layer's names | **Return value** | Method | Meaning | | ------------------------ | ----------------------- | | `HasHoroscopeStars` | All of them are present | | `HasOneOfHoroscopeStars` | At least one is present | | `NotHaveHoroscopeStars` | None is present | **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.HasHoroscopeStars(iztro.PalaceSoul, iztro.ScopeDecadal, []string{"yunlu"})) fmt.Println(h.HasOneOfHoroscopeStars(iztro.PalaceSoul, iztro.ScopeDecadal, []string{"yunlu", "yunyang"})) fmt.Println(h.NotHaveHoroscopeStars(iztro.PalaceSoul, iztro.ScopeDecadal, []string{"yuntuo"})) ``` **Output** ```text false false true ``` **Edge cases and pitfalls** Two string parameters (palace name and scope) already precede it in these three methods, and a variadic list would make call sites ambiguous, so the star parameter takes a `[]string`. Every other method in the package that takes a list of stars is variadic. All three methods use `scope` plus the palace name to locate one cell on the natal chart, but the set of stars compared against is always the **union of the decadal and yearly scope stars**, regardless of `scope`. So passing `ScopeMonthly` asks "does this cell — the monthly such-and-such palace — hold a decadal or yearly scope star?", not a monthly one: the scope stars of the monthly, daily and hourly layers take no part in the comparison. For the scope-star layout of a given layer read `h.Monthly.Stars`, or use [`GetHoroscopeStar`](/en/docs/go/star#gethoroscopestar). The decadal scope stars are `StarYunlu`, `StarYunyang` and so on, the yearly ones `StarLiulu`, `StarLiuyang` and so on; the two groups have different keys. Since the comparison set is always the union of those two groups, keys from either group can be found under any `scope` — only the palace they land in differs. The per-layer key table is on [Star placement](/en/docs/go/star#gethoroscopestar). *** ## HasHoroscopeMutagen [#hashoroscopemutagen] **Purpose** Test whether a palace under a given scope carries a mutagen flown by that scope's stem. **Zi Wei meaning** Every horoscope layer has a stem of its own, and it transforms four stars just as the birth-year stem does. A question like "does the decadal Lu land in the decadal Wealth palace?" is asking about this. **Signature** ```go func (h *Horoscope) HasHoroscopeMutagen(nameKeyOrName string, scope string, mutagenKey string) bool ``` **Parameters** | Parameter | Type | Required | Default | Description | | --------------- | -------- | -------- | ------- | -------------------------------- | | `nameKeyOrName` | `string` | Yes | — | The palace name under that scope | | `scope` | `string` | Yes | — | The horoscope scope | | `mutagenKey` | `string` | Yes | — | A mutagen key | **Return value** `bool`. It checks whether the star transformed by that layer's stem is among the major or minor stars of the target palace (adjective stars are not scanned). **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.HasHoroscopeMutagen(iztro.PalaceSoul, iztro.ScopeDecadal, iztro.MutagenLu)) fmt.Println(h.Decadal.Mutagen) ``` **Output** ```text false [sun general moon fortunate] ``` The decadal stem is geng, and geng sends Lu to Taiyang, Quan to Wuqu, Ke to Taiyin and Ji to Tiantong. **Edge cases and pitfalls** The natal layer has no "layer stem" — the natal mutagens are already marked on the stars' own `MutagenKey`. `HasHoroscopeMutagen(name, iztro.ScopeOrigin, m)` therefore returns `false` outright, which does not mean the natal chart lacks that mutagen. For natal mutagens use the palace's [`HasMutagen`](/en/docs/go/palace#hasmutagen--nothavemutagen). *** ## ScopeItem / Astrolabe [#scopeitem--astrolabe] **Purpose** Get the `HoroscopeScope` for a scope key, or get back to the natal chart. **Signature** ```go func (h *Horoscope) ScopeItem(scope string) *HoroscopeScope func (h *Horoscope) Astrolabe() *Astrolabe ``` **Return value** `ScopeItem` returns `nil` for `ScopeOrigin` or an unknown scope — the natal chart is not a horoscope layer. **Example** ```go h, _ := chart.Horoscope("2025-6-1", 0) fmt.Println(h.ScopeItem(iztro.ScopeDecadal).Name) fmt.Println(h.ScopeItem(iztro.ScopeOrigin)) fmt.Println(h.Astrolabe().SolarDate) ``` **Output** ```text decadal 2000-8-16 ``` **Edge cases and pitfalls** `ScopeItem` is for writing generic logic parameterized by scope, which is tidier than a chain of `switch scope`. Remember to check for `nil`. *** ## ToText [#totext] **Purpose** The horoscope's semantic text: a complete description for language models and people. **Signature** ```go func (h *Horoscope) ToText() (string, error) func (h *Horoscope) ToTextContext(ctx context.Context) (string, error) ``` **Return value** `string` — sectioned plain text in the chart's charting language; each scope carries a patterns line and flowing-star lines from its own perspective. The full format is on [Semantic text](/en/docs/guide/guides/to-text). **Example** ```go h, _ := chart.Horoscope("2025-1-1", 0) text, _ := h.ToText() fmt.Println(string([]rune(text)[:39])) ``` **Output** ```text === Horoscope === Target Date: 2025-1-1 ``` For the pattern hits as text, see `PatternsToText` on [Patterns](/en/docs/go/patterns).