library(tidyverse)── Attaching packages ─────────────────────────────────────── tidyverse 1.3.2 ──
✔ ggplot2 3.4.0 ✔ purrr 1.0.1
✔ tibble 3.1.8 ✔ dplyr 1.1.0
✔ tidyr 1.3.0 ✔ stringr 1.5.0
✔ readr 2.1.3 ✔ forcats 1.0.0
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag() masks stats::lag()1.What function would you use to read a file where fields were separated with “|”?
read_delim
2.Apart from file, skip, and comment, what other arguments do read_csv() and read_tsv() have in common?
they have almost all of each others arguments
3.What are the most important arguments to read_fwf()?
i don’t know i’ve never used it
4.Sometimes strings in a CSV file contain commas. To prevent them from causing problems, they need to be surrounded by a quoting character, like " or '. By default, read_csv() assumes that the quoting character will be ". To read the following text into a data frame, what argument to read_csv() do you need to specify?
colnames = false
5.Identify what is wrong with each of the following inline CSV files. What happens when you run the code?
read_csv("a,b\n1,2,3\n4,5,6")Warning: One or more parsing issues, call `problems()` on your data frame for details,
e.g.:
dat <- vroom(...)
problems(dat)Rows: 2 Columns: 2
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
dbl (1): a
num (1): b
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.# A tibble: 2 × 2
a b
<dbl> <dbl>
1 1 23
2 4 56read_csv("a,b,c\n1,2\n1,2,3,4")Warning: One or more parsing issues, call `problems()` on your data frame for details,
e.g.:
dat <- vroom(...)
problems(dat)Rows: 2 Columns: 3
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
dbl (2): a, b
num (1): c
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.# A tibble: 2 × 3
a b c
<dbl> <dbl> <dbl>
1 1 2 NA
2 1 2 34read_csv("a,b\n\1")Warning: One or more parsing issues, call `problems()` on your data frame for details,
e.g.:
dat <- vroom(...)
problems(dat)Rows: 1 Columns: 2
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
chr (1): a
lgl (1): b
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.# A tibble: 1 × 2
a b
<chr> <lgl>
1 "\u0001" NA read_csv("a,b\n1,2\na,b")Rows: 2 Columns: 2
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
chr (2): a, b
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.# A tibble: 2 × 2
a b
<chr> <chr>
1 1 2
2 a b read_csv2("a;b\n1;3")ℹ Using "','" as decimal and "'.'" as grouping mark. Use `read_delim()` for more control.
Rows: 1 Columns: 2── Column specification ────────────────────────────────────────────────────────
Delimiter: ";"
dbl (2): a, b
ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.# A tibble: 1 × 2
a b
<dbl> <dbl>
1 1 36.Practice referring to non-syntactic names in the following data frame by:
Extracting the variable called 1.
Plotting a scatterplot of 1 vs. 2.
Creating a new column called 3, which is 2 divided by 1.
Renaming the columns to one, two, and three.
annoying <- tibble(
`1` = 1:10,
`2` = `1` * 2 + rnorm(length(`1`))
)annoying %>% rename(one = `1`,two = `2`) %>%
mutate( three = two/one) %>% ggplot(aes(x = one,y = two)) +
geom_point()