Nutze Skyfield fuer praezisere Daemmerungsberechnung

2026-07-13 19:35:39 +02:00
parent dc5292735f
commit 97357a88e0
1092 changed files with 370248 additions and 61 deletions
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+# -*- coding: utf-8 -*-
+"""Routines specific to some calculation related with cultures in East Asia."""
+
+from skyfield.constants import tau
+from skyfield.nutationlib import iau2000b_radians
+
+# Names of solar terms in Simplified Chinese
+SOLAR_TERMS_ZHS = [
+    '春分',
+    '清明',
+    '谷雨',
+    '立夏',
+    '小满',
+    '芒种',
+    '夏至',
+    '小暑',
+    '大暑',
+    '立秋',
+    '处暑',
+    '白露',
+    '秋分',
+    '寒露',
+    '霜降',
+    '立冬',
+    '小雪',
+    '大雪',
+    '冬至',
+    '小寒',
+    '大寒',
+    '立春',
+    '雨水',
+    '惊蛰',
+]
+
+# Names of solar terms in Traditional Chinese
+SOLAR_TERMS_ZHT = [
+    '春分',
+    '清明',
+    '穀雨',
+    '立夏',
+    '小滿',
+    '芒種',
+    '夏至',
+    '小暑',
+    '大暑',
+    '立秋',
+    '處暑',
+    '白露',
+    '秋分',
+    '寒露',
+    '霜降',
+    '立冬',
+    '小雪',
+    '大雪',
+    '冬至',
+    '小寒',
+    '大寒',
+    '立春',
+    '雨水',
+    '驚蟄',
+]
+
+# Names of solar terms in Japanese
+SOLAR_TERMS_JP = [
+    '春分',
+    '清明',
+    '穀雨',
+    '立夏',
+    '小満',
+    '芒種',
+    '夏至',
+    '小暑',
+    '大暑',
+    '立秋',
+    '処暑',
+    '白露',
+    '秋分',
+    '寒露',
+    '霜降',
+    '立冬',
+    '小雪',
+    '大雪',
+    '冬至',
+    '小寒',
+    '大寒',
+    '立春',
+    '雨水',
+    '啓蟄',
+]
+
+# Names of solar terms in Vietnamese
+SOLAR_TERMS_VN = [
+    'Xuân phân',
+    'Thanh minh',
+    'Cốc vũ',
+    'Lập hạ',
+    'Tiểu mãn',
+    'Mang chủng',
+    'Hạ chí',
+    'Tiểu thử',
+    'Đại thử',
+    'Lập thu',
+    'Xử thử',
+    'Bạch lộ',
+    'Thu phân',
+    'Hàn lộ',
+    'Sương giáng',
+    'Lập đông',
+    'Tiểu tuyết',
+    'Đại tuyết',
+    'Đông chí',
+    'Tiểu hàn',
+    'Đại hàn',
+    'Lập xuân',
+    'Vũ thủy',
+    'Kinh trập',
+]
+
+def solar_terms(ephemeris):
+    """Build a function of time that returns the solar terms of the year.
+
+    The function that this returns will expect a single argument that is
+    a :class:`~skyfield.timelib.Time` and will return 0 through 23 for
+    the solar terms.
+
+    The name of the solar terms may vary in different cultures, so we
+    have table of names in Simplified Chinese, Traditional Chinese,
+    Japanese and Vietnamese
+
+    Reference:
+
+    https://en.wikipedia.org/wiki/Solar_term
+
+    """
+    earth = ephemeris['earth']
+    sun = ephemeris['sun']
+
+    def solar_term_at(t):
+        """Return season 0 through 23 at time `t`."""
+        t._nutation_angles_radians = iau2000b_radians(t)
+        e = earth.at(t)
+        _, slon, _ = e.observe(sun).apparent().ecliptic_latlon('date')
+        return (slon.radians // (tau / 24) % 24).astype(int)
+
+    solar_term_at.step_days = 14.0
+    return solar_term_at