polars.Expr.cos

Expr.cos() → Expr

Compute the element-wise value for the cosine.

Returns:

Expr

Expression of data type Float64.

Notes

The argument must be in radians. To convert from degrees to radians, call .radians().

Examples

>>> from math import pi
>>> df = pl.DataFrame({"a": [0.0, pi / 2]})
>>> df.select(pl.col("a").cos())
shape: (2, 1)
┌────────────┐
│ a          │
│ ---        │
│ f64        │
╞════════════╡
│ 1.0        │
│ 6.1232e-17 │
└────────────┘
>>> df = pl.DataFrame({"a": [0.0, 90]})
>>> df.select(pl.col("a").radians().cos())
shape: (2, 1)
┌────────────┐
│ a          │
│ ---        │
│ f64        │
╞════════════╡
│ 1.0        │
│ 6.1232e-17 │
└────────────┘