Initial support for sidereal zodiac

joaoventura · joaoventura · commit ca37f9e551f6 · 2019-07-26T12:06:12.000+01:00
diff --git a/flatlib/const.py b/flatlib/const.py
@@ -254,6 +254,17 @@
 ALL_ASPECTS = MAJOR_ASPECTS + MINOR_ASPECTS
 
 
+# === Ayanamsas / Sidereal Zodiac === */
+
+AY_FAGAN_BRADLEY = "Ayanamsa Fagan Bradley"
+AY_LAHIRI = "Ayanamsa Lahiri"
+AY_DELUCE = "Ayanamsa De Luce"
+AY_RAMAN = "Ayanamsa Raman"
+AY_KRISHNAMURTI = "Ayanamsa Krishnamurti"
+AY_ALDEBARAN_15TAU = "Ayanamsa Aldebaran 15 Taurus"
+AY_GALCENTER_5SAG = "Ayanamsa Galactic Eq. 05 Sag"
+
+
 # === Some Lists === */
 
 LIST_SIGNS = [
diff --git a/flatlib/ephem/swe.py b/flatlib/ephem/swe.py
@@ -50,6 +50,17 @@
     const.HOUSES_MORINUS: b'M'
 }
 
+# Map ayanamsas
+SWE_AYANAMSAS = {
+    const.AY_FAGAN_BRADLEY: 0,
+    const.AY_LAHIRI: 1,
+    const.AY_DELUCE: 2,
+    const.AY_RAMAN: 3,
+    const.AY_KRISHNAMURTI: 4,
+    const.AY_ALDEBARAN_15TAU: 14,
+    const.AY_GALCENTER_5SAG: 17
+}
+
 
 # ==== Internal functions ==== #
 
@@ -71,13 +82,15 @@ def sweObject(obj, jd):
         'lonspeed': sweList[3],
         'latspeed': sweList[4]
     }
-    
+
+
 def sweObjectLon(obj, jd):
     """ Returns the longitude of an object. """
     sweObj = SWE_OBJECTS[obj]
     sweList = swisseph.calc_ut(jd, sweObj)
     return sweList[0]
 
+
 def sweNextTransit(obj, jd, lat, lon, flag):
     """ Returns the julian date of the next transit of
     an object. The flag should be 'RISE' or 'SET'. 
@@ -113,6 +126,7 @@ def sweHouses(jd, lat, lon, hsys):
     ]
     return (houses, angles)
     
+
 def sweHousesLon(jd, lat, lon, hsys):
     """ Returns lists with house and angle longitudes. """
     hsys = SWE_HOUSESYS[hsys]
@@ -160,6 +174,7 @@ def solarEclipseGlobal(jd, backward):
         'center_line_end': sweList[1][7],
     }
 
+
 def lunarEclipseGlobal(jd, backward):
     """ Returns the jd details of previous or next global lunar eclipse. """
 
@@ -173,3 +188,15 @@ def lunarEclipseGlobal(jd, backward):
         'penumbral_begin': sweList[1][6],
         'penumbral_end': sweList[1][7],
     }
+
+
+# === Sidereal zodiac === #
+
+def get_ayanamsa(jd, mode):
+    """
+    Returns the distance of the tropical vernal point
+    from the sidereal zero point of the zodiac.
+    """
+    eph_mode = SWE_AYANAMSAS[mode]
+    swisseph.set_sid_mode(eph_mode, 0, 0)
+    return swisseph.get_ayanamsa_ut(jd)
diff --git a/recipes/siderealzodiac.py b/recipes/siderealzodiac.py
@@ -0,0 +1,25 @@
+"""
+    Author: João Ventura <flatangleweb@gmail.com>
+
+
+    This recipe shows sample code for creating a chart
+    with sidereal zodiac
+
+"""
+
+from flatlib import const
+from flatlib.chart import Chart
+from flatlib.datetime import Datetime
+from flatlib.geopos import GeoPos
+from flatlib.ephem import swe, eph
+
+# Build a chart for a date and location
+date = Datetime('2015/03/13', '17:00', '+00:00')
+pos = GeoPos('38n32', '8w54')
+chart = Chart(date, pos)
+
+# Update object with the ayanamsa value
+asc = chart.get(const.HOUSE10)
+new_lon = asc.lon - swe.get_ayanamsa(date.jd, const.AY_LAHIRI)
+asc.relocate(new_lon)
+print(asc)
