How to make certain portions of a data frame percentages?

Question

Here is my data frame called cat_data

print(cat_data)

Metrics                2016    2017    2018    
Number of Cats         100     120      150     
Number Leaving         32      40       65
Number Staying         68      80       85 
Percent of Leavers     .32     .33      .43
Percent of Stayers     .68     .67      .57 

I want to convert only rows and 5 to percents with the percent symbol.

Here is my desired output.

Metrics                2016    2017    2018    
Number of Cats         100     120      150     
Number Leaving         32      40       65
Number Staying         68      80       85 
Percent of Leavers     32%     33%      43%
Percent of Stayers     68%     67%      57% 

I tried this but I couldn't get it to work.

cat_data[4:5,2:4] <- paste0(cat_data[4:5,2:4] * 100,%)

Can anyone tell me what I need to fix? thank you.

Answer 1

this should work as well

EDIT

The paste function requires a vector as input, but your input cat_data[4:5,2:4] is a dataframe.

The apply function takes array as input and outputs a vector.

cat_data[4:5,2:4] <- apply(cat_data[4:5,2:4]*100, 2, function(x) paste0(x, "%"))

you take your region of the data frame and multiply by 100. This will be your array input in the apply function. By indicating the margin = 2 the vectorization is performed by column. then you supply the function applied to the vector which in this case is the paste function with your desired % character.