Add arcus trigonometry functions to templates

homeassistant/helpers/template.py

@@ -714,6 +714,41 @@ def tangent(value):
         return value
 
 
+def arc_sine(value):
+    """Filter to get arc sine of the value."""
+    try:
+        return math.asin(float(value))
+    except (ValueError, TypeError):
+        return value
+
+
+def arc_cosine(value):
+    """Filter to get arc cosine of the value."""
+    try:
+        return math.acos(float(value))
+    except (ValueError, TypeError):
+        return value
+
+
+def arc_tangent(value):
+    """Filter to get arc tangent of the value."""
+    try:
+        return math.atan(float(value))
+    except (ValueError, TypeError):
+        return value
+
+
+def arc_tangent2(*args):
+    """Filter to calculate four quadrant arc tangent of y / x."""
+    try:
+        if len(args) == 1 and isinstance(args[0], (list, tuple)):
+            args = args[0]
+
+        return math.atan2(float(args[0]), float(args[1]))
+    except (ValueError, TypeError):
+        return args
+
+
 def square_root(value):
     """Filter to get square root of the value."""
     try:
@@ -872,6 +907,10 @@ def __init__(self, hass):
         self.filters["sin"] = sine
         self.filters["cos"] = cosine
         self.filters["tan"] = tangent
+        self.filters["asin"] = arc_sine
+        self.filters["acos"] = arc_cosine
+        self.filters["atan"] = arc_tangent
+        self.filters["atan2"] = arc_tangent2
         self.filters["sqrt"] = square_root
         self.filters["as_timestamp"] = forgiving_as_timestamp
         self.filters["timestamp_custom"] = timestamp_custom
@@ -899,6 +938,10 @@ def __init__(self, hass):
         self.globals["pi"] = math.pi
         self.globals["tau"] = math.pi * 2
         self.globals["e"] = math.e
+        self.globals["asin"] = arc_sine
+        self.globals["acos"] = arc_cosine
+        self.globals["atan"] = arc_tangent
+        self.globals["atan2"] = arc_tangent2
         self.globals["float"] = forgiving_float
         self.globals["now"] = dt_util.now
         self.globals["utcnow"] = dt_util.utcnow

tests/helpers/test_template.py

@@ -349,6 +349,101 @@ def test_sqrt(hass):
         )
 
 
+def test_arc_sine(hass):
+    """Test arcus sine."""
+    tests = [
+        (-2.0, "-2.0"),  # value error
+        (-1.0, "-1.571"),
+        (-0.5, "-0.524"),
+        (0.0, "0.0"),
+        (0.5, "0.524"),
+        (1.0, "1.571"),
+        (2.0, "2.0"),  # value error
+        ('"error"', "error"),
+    ]
+
+    for value, expected in tests:
+        assert (
+            template.Template("{{ %s | asin | round(3) }}" % value, hass).async_render()
+            == expected
+        )
+
+
+def test_arc_cos(hass):
+    """Test arcus cosine."""
+    tests = [
+        (-2.0, "-2.0"),  # value error
+        (-1.0, "3.142"),
+        (-0.5, "2.094"),
+        (0.0, "1.571"),
+        (0.5, "1.047"),
+        (1.0, "0.0"),
+        (2.0, "2.0"),  # value error
+        ('"error"', "error"),
+    ]
+
+    for value, expected in tests:
+        assert (
+            template.Template("{{ %s | acos | round(3) }}" % value, hass).async_render()
+            == expected
+        )
+
+
+def test_arc_tan(hass):
+    """Test arcus tangent."""
+    tests = [
+        (-10.0, "-1.471"),
+        (-2.0, "-1.107"),
+        (-1.0, "-0.785"),
+        (-0.5, "-0.464"),
+        (0.0, "0.0"),
+        (0.5, "0.464"),
+        (1.0, "0.785"),
+        (2.0, "1.107"),
+        (10.0, "1.471"),
+        ('"error"', "error"),
+    ]
+
+    for value, expected in tests:
+        assert (
+            template.Template("{{ %s | atan | round(3) }}" % value, hass).async_render()
+            == expected
+        )
+
+
+def test_arc_tan2(hass):
+    """Test two parameter version of arcus tangent."""
+    tests = [
+        (-10.0, -10.0, "-2.356"),
+        (-10.0, 0.0, "-1.571"),
+        (-10.0, 10.0, "-0.785"),
+        (0.0, -10.0, "3.142"),
+        (0.0, 0.0, "0.0"),
+        (0.0, 10.0, "0.0"),
+        (10.0, -10.0, "2.356"),
+        (10.0, 0.0, "1.571"),
+        (10.0, 10.0, "0.785"),
+        (-4.0, 3.0, "-0.927"),
+        (-1.0, 2.0, "-0.464"),
+        (2.0, 1.0, "1.107"),
+        ('"duck"', '"goose"', "('duck', 'goose')"),
+    ]
+
+    for y, x, expected in tests:
+        assert (
+            template.Template(
+                "{{ (%s, %s) | atan2 | round(3) }}" % (y, x), hass
+            ).async_render()
+            == expected
+        )
+        assert (
+            template.Template(
+                "{{ atan2(%s, %s) | round(3) }}" % (y, x), hass
+            ).async_render()
+            == expected
+        )
+
+
 def test_strptime(hass):
     """Test the parse timestamp method."""
     tests = [