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I am trying to round these values to one digit ( the output values must be 2.4, 0.0 and so on) but when I use round(dataframe, 1) I get all "0"s or Inf. What is wrong ?

Andrea Dalla Rosa
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    hello :) this is normal behaviour maybe try with `signif()` instead of `round()`, `> round(0.000000001, 1) [1] 0 > signif(0.000000001, 1) [1] 1e-09` – Paul May 05 '20 at 08:07
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    Ciao Andrea and welcome to SO. First of all you should read [here](https://stackoverflow.com/help/how-to-ask) about how to ask a good question; a good question has better changes to be solved and you to receive help. On the other hand a read of [this](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example) is also good. It explains how to create a reproducible example in R. Help users to help you by providing a piece of your data a desired output and things you have tried so far. Last but not least, are you sure that `round(dataframe, 1)` works? – SabDeM May 05 '20 at 08:16
  • @SabDeM it seems that `round()` can take a dataframe; `round(as.data.frame(iris[1:4]))` produces the expected outcome. – Paul May 05 '20 at 08:26
  • options(scipen = 999) prevents scientific notation – Dr. Flow May 05 '20 at 08:28

1 Answers1

0

You can use applyand round thus:

Some illustrative data:

set.seed(12)
df <- data.frame(
  v1 = rnorm(10),
  v2 = rnorm(10),
  v3 = rnorm(10)
)

df
           v1          v2         v3
1  -1.4805676 -0.77771958  0.2236414
2   1.5771695 -1.29388230  2.0072015
3  -0.9567445 -0.77956651  1.0119791
4  -0.9200052  0.01195176 -0.3024592
5  -1.9976421 -0.15241624 -1.0252448
6  -0.2722960 -0.70346425 -0.2673848
7  -0.3153487  1.18887916 -0.1991057
8  -0.6282552  0.34051227  0.1311226
9  -0.1064639  0.50696817  0.1457999
10  0.4280148 -0.29330515  0.3620647

Solution:

df <- apply(df, 2, round, 1)
df
        v1   v2   v3
 [1,] -1.5 -0.8  0.2
 [2,]  1.6 -1.3  2.0
 [3,] -1.0 -0.8  1.0
 [4,] -0.9  0.0 -0.3
 [5,] -2.0 -0.2 -1.0
 [6,] -0.3 -0.7 -0.3
 [7,] -0.3  1.2 -0.2
 [8,] -0.6  0.3  0.1
 [9,] -0.1  0.5  0.1
[10,]  0.4 -0.3  0.4

EDIT:

Alternatively, you can use dplyr:

library(dplyr)
df %>% mutate_all(round, 1)

And by the way, round(df, 1) works too!

Chris Ruehlemann
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  • May I suggest an improvement, according to the sceenshot attached to the question, numbers are very small, when you `round()` them, you get 0 (ex : round 2,2333e-10 one decimal is 0.0). I think that @Andrea Dalla Rosa was looking for significant digits i.e 2.2333e-10 ----> 2.2e-10. Then function `signif()` is more relevant I think than `round()` – Paul May 05 '20 at 10:54