Changed int to float and started on actual tests

src/analemma/plot.py

@@ -20,7 +20,7 @@ class DialParameters:
     Parameters defining a sundial
 
     Parameters:
-        theta: $90^\circ - \\theta$ is the latitude of the sundial
+        theta: $90^\\circ - \\theta$ is the latitude of the sundial
         iota: Inclination of the gnomon
         i: Inclination of the dial face
         d: Declination of the dial face
@@ -217,7 +217,7 @@ def orbit_date_to_day(the_date: datetime.date, year=2024) -> int:
 
 
 def sunray_dialface_angle_over_one_year(
-    planet: orbit.PlanetParameters, dial: DialParameters, hour_offset=0
+    planet: orbit.PlanetParameters, dial: DialParameters, hour_offset: float = 0.0
 ):
     """
     Calculate daily the time since perihelion in seconds and the corresponding sin(sunray-dialface angle)
@@ -283,7 +283,10 @@ def _plot_analemma_segment(
 
 
 def _analemma_plot_sampling_times(
-    season: Season, hour_offset, planet: orbit.PlanetParameters, dial: DialParameters
+    season: Season,
+    hour_offset: float,
+    planet: orbit.PlanetParameters,
+    dial: DialParameters,
 ):
     # season lengths are [89, 91, 94, 91] (Winter Spring Summer Autumn)
     # place equinoxes and solstices in the middle for plotting
@@ -319,12 +322,21 @@ def _analemma_plot_sampling_times(
 def plot_analemma_season_segment(
     ax,
     season: Season,
-    hour_offset: int,
+    hour_offset: float,
     planet: orbit.PlanetParameters,
     dial: DialParameters,
     **kwargs,
 ):
-    "Plot the analemma segment for the given season"
+    """
+    Plot the analemma segment for the given season
+
+    Parameters:
+        ax: matplotlib axes
+        season: The given season
+        hour_offset: Number of hours relative to noon, eg -2.25 corresponds to 9:45am
+        planet: The planet on which the dial is located
+        dial: The orientation and location of the sundial
+    """
 
     times = _analemma_plot_sampling_times(season, hour_offset, planet, dial)
     return _plot_analemma_segment(
@@ -395,7 +407,7 @@ def plot_special_sun_path(
 
 def _analemma_point_coordinates(
     days_since_perihelion: int,
-    hour_offset: int,
+    hour_offset: float,
     planet: orbit.PlanetParameters,
     dial: DialParameters,
 ):
@@ -444,7 +456,7 @@ def _furthest_point(p1, p2):
 
 
 def _analemma_label_coordinates(
-    hour_offset: int, planet: orbit.PlanetParameters, dial: DialParameters
+    hour_offset: float, planet: orbit.PlanetParameters, dial: DialParameters
 ):
     june_solstice_day, december_solstice_day = _solstice_days(planet, dial)
 
@@ -477,6 +489,8 @@ def falls_on_dial(x, y):
 def hour_offset_to_oclock(hour_offset: int):
     """
     Render an integer hour offset (eg +2) as the corresponding time (eg '2pm')
+
+    Note that any non-integer part of the hour offset will be truncated
     """
     if hour_offset == 0:
         return "12pm"
@@ -495,6 +509,8 @@ def annotate_analemma_with_hour(
 ):
     """
     For the given hour, annotate with the time
+
+    Note that any non-integer part of the hour offset will be truncated
     """
     if hour_offset % 3 == 0:
         points = _analemma_label_coordinates(hour_offset, planet, dial)

tests/conftest.py

@@ -0,0 +1,16 @@
+import pytest
+import numpy as np
+from analemma import orbit
+from analemma import plot as ap
+
+
+@pytest.fixture
+def earth():
+    return orbit.PlanetParameters.earth()
+
+
+@pytest.fixture
+def camdial():
+    return ap.DialParameters(
+        theta=37.5 / 180 * np.pi, iota=37.5 / 180 * np.pi, i=0, d=0
+    )  # Analemmatic dial in Cambridge, UK

tests/test_plot.py

@@ -0,0 +1,54 @@
+import datetime
+import numpy as np
+from analemma import plot as ap
+
+
+def test_sun_rise_noon_set(earth, camdial):
+    st = ap.find_sun_rise_noon_set_relative_to_dial_face(
+        days_since_perihelion=50, planet=earth, dial=camdial
+    )
+    assert (
+        st.sunrise.hours_from_midnight
+        < st.noon.hours_from_midnight
+        < st.sunset.hours_from_midnight
+    )
+
+
+def test_solstices(earth, camdial):
+    """
+    The June and December solstices should occur on the longest and shortest day of the year as seen on a horizontal dial
+    """
+
+    sun_times = [
+        ap.find_sun_rise_noon_set_relative_to_dial_face(
+            days_since_perihelion, earth, camdial
+        )
+        for days_since_perihelion in np.arange(0, 365)
+    ]
+
+    day_lengths = [
+        st.sunset.hours_from_midnight - st.sunrise.hours_from_midnight
+        for st in sun_times
+    ]
+    december_solstice = np.argmin(day_lengths)
+    june_solstice = np.argmax(day_lengths)
+
+    assert ap.orbit_day_to_date(0) == datetime.date.fromisoformat("2024-01-03")
+    assert ap.orbit_day_to_date(june_solstice) == datetime.date.fromisoformat(
+        "2024-06-21"
+    )
+    assert ap.orbit_day_to_date(december_solstice) == datetime.date.fromisoformat(
+        "2024-12-21"
+    )
+
+    assert ap.orbit_date_to_day(datetime.date.fromisoformat("2024-01-03")) == 0
+    assert (
+        ap.orbit_date_to_day(datetime.date.fromisoformat("2024-06-21")) == june_solstice
+    )
+    assert (
+        ap.orbit_date_to_day(datetime.date.fromisoformat("2024-12-21"))
+        == december_solstice
+    )
+
+    arbitrary_date = datetime.date.fromisoformat("2024-05-26")
+    assert ap.orbit_day_to_date(ap.orbit_date_to_day(arbitrary_date)) == arbitrary_date