Truncate numeric data toward zero to decimals number of decimal places

Source code

Description

Truncate numeric data toward zero to decimals number of decimal places

Usage

<Expr>$truncate(decimals = 0L)

Arguments

decimals

Number of decimal places to truncate to.

Details

Truncation discards the fractional part beyond the given number of decimals. For example, when truncating to 0 decimals, 0.25, -0.25, 0.99, and -0.99 will all round to 0. When truncating to 1 decimal 1.9999 rounds to 1.9 and -1.9999 rounds to -1.9. There is no tiebreak behaviour at midpoint values as there is with $round() so 0.5 and -0.5 will also round to 0 when decimals = 0.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(n = c(-9.9999, 0.12345, 1.0251, 8.8765))
df$with_columns(
  t0 = pl$col("n")$truncate(0),
  t1 = pl$col("n")$truncate(1),
  t2 = pl$col("n")$truncate(2),
  t3 = pl$col("n")$truncate(3),
  t4 = pl$col("n")$truncate(4),
)

#> shape: (4, 6)
#> ┌─────────┬──────┬──────┬───────┬────────┬─────────┐
#> │ n       ┆ t0   ┆ t1   ┆ t2    ┆ t3     ┆ t4      │
#> │ ---     ┆ ---  ┆ ---  ┆ ---   ┆ ---    ┆ ---     │
#> │ f64     ┆ f64  ┆ f64  ┆ f64   ┆ f64    ┆ f64     │
#> ╞═════════╪══════╪══════╪═══════╪════════╪═════════╡
#> │ -9.9999 ┆ -9.0 ┆ -9.9 ┆ -9.99 ┆ -9.999 ┆ -9.9999 │
#> │ 0.12345 ┆ 0.0  ┆ 0.1  ┆ 0.12  ┆ 0.123  ┆ 0.1234  │
#> │ 1.0251  ┆ 1.0  ┆ 1.0  ┆ 1.02  ┆ 1.025  ┆ 1.025   │
#> │ 8.8765  ┆ 8.0  ┆ 8.8  ┆ 8.87  ┆ 8.876  ┆ 8.8765  │
#> └─────────┴──────┴──────┴───────┴────────┴─────────┘