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rdplyrscalenormalize

Normalizing by Group In R


I am trying to normalize a dataframe by group in R. The reason why I am doing this is because I want to run a regression equation on each group for the revenue and want to obtain the slope. Because the data is not normally distributed, I wanted to normalize the dataset by group to get a better read on the trend.

The function I am using to normalize the dataset is as follows:

 normalize <- function(x){
   return((x-min(x)) / max(x)-min(x))
 }

I know there is another already built function in R called scale.

My datafame looks like this:

df 
         Date    Partner    Revenue 
1  2017-03-01          A      33121
2  2017-03-02          A      32758
3  2017-03-03          A      34675
4  2017-03-04          A      32407
5  2017-03-05          A      30851
6  2017-03-06          A      33248
7  2017-03-07          A      34288
8  2017-03-08          A      33820
9  2017-03-09          A      36021
10 2017-03-10          A      38757
11 2017-03-11          A      41149
12 2017-03-12          A      36203
13 2017-03-13          A      41167
14 2017-03-14          A      50237
15 2017-03-15          A      48463
16 2017-03-01          B       2123
17 2017-03-02          B       1684
18 2017-03-03          B       1246
19 2017-03-04          B       1099
20 2017-03-05          B       2314
21 2017-03-06          B       1565
22 2017-03-07          B       1610
23 2017-03-08          B       1749
24 2017-03-09          B       1917
25 2017-03-10          B       1784
26 2017-03-11          B       1662
27 2017-03-12          B       1748
28 2017-03-13          B       1452
29 2017-03-14          B        880
30 2017-03-15          B        591

Using the normalize function I tried this route, but the NEWREV numbers are not between 0 and 1. Rather they range from -30,000 to -590.

scaled_data <- 
  df %>%
  group_by(`Partner`) %>%
  mutate(NEWREV = normalize(Revenue))

How would I scale my revenue by group so that the numbers are between 0 and 1?


Solution

  • It looks like you are missing some parentheses in your definition of the function normalize:

    normalize <- function(x){
      return((x-min(x)) / (max(x)-min(x)))
    }