I'm trying to print only the first 45 rows of a tibble data frame:
print( data_frame_name, n = 45)
This will return the first 45 rows of my DF.
However, when I tried to specify a column using the dollar sign operator "$" such that
print( data_frame_name$column_name, n = 45)
R gave me an error message "invalid 'na.print' specification", is there something I am missing?
I would try a workaround method but the problem asks that I use "$" and print().
There are many methods for print (depends on the packages loaded as well) and the print method is dispatched based on the class of the dataset. If we have a tibble object, then the print.tbl is dispatched and it have the n option whereas if the object is not a tibble, a different method is used. When we extract a column, it is a vector. head may be more general
head(data_frame_name$column_name, n = 45)
It can be reproduced with mtcars
print(as_tibble(mtcars), n = 5)
# A tibble: 32 x 11
# mpg cyl disp hp drat wt qsec vs am gear carb
# <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#1 21 6 160 110 3.9 2.62 16.5 0 1 4 4
#2 21 6 160 110 3.9 2.88 17.0 0 1 4 4
#3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1
#4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1
#5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2
# … with 27 more rows
It works because the print.tbl have the n option
getAnywhere('print.tbl')
function (x, ..., n = NULL, width = NULL, n_extra = NULL)
{
cli::cat_line(format(x, ..., n = n, width = width, n_extra = n_extra))
invisible(x)
}
whereas the arguments for print.data.frame doesn't have
args(print.data.frame)
#function (x, ..., digits = NULL, quote = FALSE, right = TRUE,
#row.names = TRUE, max = NULL)
nor does the print.default
args(print.default)
#function (x, digits = NULL, quote = TRUE, na.print = NULL, print.gap = NULL,
# right = FALSE, max = NULL, width = NULL, useSource = TRUE,
# ...)
How about
print(data_frame_name$column_name[1:45])
if you're required to use print and $?