How can I force R to display 2 decimal points in a large double?

Question

I'm trying to sum a vector of doubles in a data frame. When the sum is relatively low, this works as intended.

df <- data.frame(
  numbers = c(50, 632.5, 12.45)
)

sum(df$numbers)
# 694.95

But when the sum gets higher, the R begins to round the sum.

df <- data.frame(
  numbers = c(50000000, 632.5, 12.45)
)
sum(df$numbers)
# 50000645

How can I stop R from eliminating these decimal points? The output I want is:

sum(df$numbers)
# 50000645.95

Note that you can encounter [floating point](http://stackoverflow.com/a/9508558/1412059) issues. You might need [arbitrary precision](https://cran.r-project.org/web/packages/Rmpfr/vignettes/Rmpfr-pkg.pdf) numbers. — Roland, Nov 01 '16 at 14:00

score 2 · Accepted Answer · answered Nov 01 '16 at 13:58

2

Try setting the number of digits in options, you can set whatever works for you. For example:

options(digits = 10)
sum(df$numbers)
[1] 50000644.95

answered Nov 01 '16 at 13:58

Zach

score 0 · Answer 2 · answered Nov 01 '16 at 18:01

0

Alternatively, if you only want to change the settings for this computation, you could use:

    print(sum(df$numbers, digits = 10))

answered Nov 01 '16 at 18:01

Antti

2 Answers2