polars.Expr.log1p

Expr.log1p() → Self

Compute the natural logarithm of each element plus one.

This computes log(1 + x) but is more numerically stable for x close to zero.

Examples

>>> df = pl.DataFrame({"a": [1, 2, 3]})
>>> df.select(pl.col("a").log1p())
shape: (3, 1)
┌──────────┐
│ a        │
│ ---      │
│ f64      │
╞══════════╡
│ 0.693147 │
│ 1.098612 │
│ 1.386294 │
└──────────┘