Fix invalid inputs for trigonometric functions (#4164)

polars/polars-lazy/src/dsl/function_expr/trigonometry.rs

@@ -16,10 +16,17 @@ pub(super) fn apply_trigonometric_function(
             let ca = s.f64().unwrap();
             apply_trigonometric_function_to_float(ca, trig_function)
         }
-        _ => {
+        dt if dt.is_numeric() => {
             let s = s.cast(&DataType::Float64)?;
             apply_trigonometric_function(&s, trig_function)
         }
+        dt => Err(PolarsError::ComputeError(
+            format!(
+                "cannot use trigonometric function on Series of dtype: {:?}",
+                dt
+            )
+            .into(),
+        )),
     }
 }
 

py-polars/tests/test_series.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import math
 from datetime import date, datetime
 from typing import Any
 from unittest.mock import patch
@@ -1127,18 +1128,6 @@ def test_comparisons_bool_series_to_int() -> None:
         srs_bool > 2  # noqa: B015
 
 
-def test_trigonometry_functions() -> None:
-    srs_float = pl.Series("t", [0.0, np.pi])
-    assert np.allclose(srs_float.sin(), np.array([0.0, 0.0]))
-    assert np.allclose(srs_float.cos(), np.array([1.0, -1.0]))
-    assert np.allclose(srs_float.tan(), np.array([0.0, -0.0]))
-
-    srs_float = pl.Series("t", [1.0, 0.0, -1])
-    assert np.allclose(srs_float.arcsin(), np.array([1.571, 0.0, -1.571]), atol=0.01)
-    assert np.allclose(srs_float.arccos(), np.array([0.0, 1.571, 3.142]), atol=0.01)
-    assert np.allclose(srs_float.arctan(), np.array([0.785, 0.0, -0.785]), atol=0.01)
-
-
 def test_abs() -> None:
     # ints
     s = pl.Series([1, -2, 3, -4])
@@ -1530,11 +1519,23 @@ def test_is_between_datetime() -> None:
 )
 @pytest.mark.filterwarnings("ignore:invalid value encountered:RuntimeWarning")
 def test_trigonometric(f: str) -> None:
-    s = pl.Series("a", [0.0])
+    s = pl.Series("a", [0.0, math.pi])
     expected = pl.Series("a", getattr(np, f)(s.to_numpy()))
     verify_series_and_expr_api(s, expected, f)
 
 
+def test_trigonometric_invalid_input() -> None:
+    # String
+    s = pl.Series("a", ["1", "2", "3"])
+    with pytest.raises(pl.ComputeError):
+        s.sin()
+
+    # Date
+    s = pl.Series("a", [date(1990, 2, 28), date(2022, 7, 26)])
+    with pytest.raises(pl.ComputeError):
+        s.cosh()
+
+
 def test_ewm_mean() -> None:
     a = pl.Series("a", [2, 5, 3])
     expected = pl.Series(