DannyBen/datamix

# round

Round all values in a column.

```ruby
require 'datamix'
using DataMix

sp500 = file '../_data/sp500.csv'

# Option 1, call #round on the data table
sp500.keep :date, :open, :close, :volume
sp500.round :close, decimals: 2
sp500.round :volume

# Option 2, call #round on the column
sp500[:open] = sp500[:open].round 1

sp500.preview

```

# Output

```
+------------+--------+---------+------------+
| date       | open   | close   | volume     |
+------------+--------+---------+------------+
| 2015-03-11 | 2044.7 | 2040.24 | 3406570000 |
| 2015-03-12 | 2041.1 | 2065.95 | 3405860000 |
| 2015-03-13 | 2064.6 | 2053.4  | 3498560000 |
| 2015-03-16 | 2055.4 | 2081.19 | 3295600000 |
| 2015-03-17 | 2080.6 | 2074.28 | 3221840000 |
| 2015-03-18 | 2072.8 | 2099.5  | 4128210000 |
| 2015-03-19 | 2098.7 | 2089.27 | 3305220000 |
| 2015-03-20 | 2090.3 | 2108.1  | 5554120000 |
| 2015-03-23 | 2108.0 | 2104.42 | 3267960000 |
| 2015-03-24 | 2103.9 | 2091.5  | 3189820000 |
+------------+--------+---------+------------+
```