[R] round() a data frame containing 'character' variables?

[Liviu Andronic]

Hello

On Wed, Aug 10, 2011 at 2:31 PM, Jean V Adams <jvadams at usgs.gov> wrote:
> The function format() might serve your needs.
>
This looks very promising, but yields some strange results. See below:

> x <- data.frame(a=rnorm(10), b=rnorm(10), c=rnorm(10), d=letters[1:10])
> x
             a           b            c d
1   0.54114449 -0.11195580  1.526279364 a
2   3.27109063  0.50848249 -0.215760332 b
3  -0.27064475 -1.04749725  0.082319811 c
4  -0.06638611 -0.58600572  0.004148253 d
5  -0.06170739 -0.37885203  0.689125494 e
6   0.53211363 -0.09150913 -0.463972307 f
7  -0.43314431 -0.28981614 -0.973410994 g
8   0.52137857 -1.15077343  0.163120205 h
9  -1.39581552  1.27378389  0.136708313 i
10  0.06348058 -0.00369746 -0.570214119 j
> format(x, digits=2)  ##it displays 3 or 4 digits, instead of the required 2
        a       b       c d
1   0.541 -0.1120  1.5263 a
2   3.271  0.5085 -0.2158 b
3  -0.271 -1.0475  0.0823 c
4  -0.066 -0.5860  0.0041 d
5  -0.062 -0.3789  0.6891 e
6   0.532 -0.0915 -0.4640 f
7  -0.433 -0.2898 -0.9734 g
8   0.521 -1.1508  0.1631 h
9  -1.396  1.2738  0.1367 i
10  0.063 -0.0037 -0.5702 j
> format(x, digits=2, nsmall=1, scientific=7)  ##no change when setting related arguments
        a       b       c d
1   0.541 -0.1120  1.5263 a
2   3.271  0.5085 -0.2158 b
3  -0.271 -1.0475  0.0823 c
4  -0.066 -0.5860  0.0041 d
5  -0.062 -0.3789  0.6891 e
6   0.532 -0.0915 -0.4640 f
7  -0.433 -0.2898 -0.9734 g
8   0.521 -1.1508  0.1631 h
9  -1.396  1.2738  0.1367 i
10  0.063 -0.0037 -0.5702 j
> round(x[1:3], digits=2)  ##works as expected
       a     b     c
1   0.54 -0.11  1.53
2   3.27  0.51 -0.22
3  -0.27 -1.05  0.08
4  -0.07 -0.59  0.00
5  -0.06 -0.38  0.69
6   0.53 -0.09 -0.46
7  -0.43 -0.29 -0.97
8   0.52 -1.15  0.16
9  -1.40  1.27  0.14
10  0.06  0.00 -0.57

Any ideas why format() and round() give so different results? Can
format() be set to behave similarly to round? Regards
Liviu