This function converts a variable into a factor, but preserves variable and value label attributes.

```
as_factor(x, ...)
to_factor(x, ...)
# S3 method for data.frame
as_factor(x, ..., add.non.labelled = FALSE)
```

x | A vector or data frame. |
---|---|

... | Optional, unquoted names of variables that should be selected for
further processing. Required, if |

add.non.labelled | Logical, if |

A factor, including variable and value labels. If `x`

is a data frame, the complete data frame `x`

will be returned,
where variables specified in `...`

are coerced
to factors (including variable and value labels);
if `...`

is not specified, applies to all variables in the
data frame.

`as_factor`

converts numeric values into a factor with numeric
levels. `as_label`

, however, converts a vector into
a factor and uses value labels as factor levels.

This function is intended for use with vectors that have value and variable
label attributes. Unlike `as.factor`

, `as_factor`

converts
a variable into a factor and preserves the value and variable label attributes.

Adding label attributes is automatically done by importing data sets
with one of the `read_*`

-functions, like `read_spss`

.
Else, value and variable labels can be manually added to vectors
with `set_labels`

and `set_label`

.

```
if (require("sjmisc") && require("magrittr")) {
data(efc)
# normal factor conversion, loses value attributes
x <- as.factor(efc$e42dep)
frq(x)
# factor conversion, which keeps value attributes
x <- as_factor(efc$e42dep)
frq(x)
# create partially labelled vector
x <- set_labels(
efc$e42dep,
labels = c(
`1` = "independent",
`4` = "severe dependency",
`9` = "missing value"
))
# only copy existing value labels
as_factor(x) %>% head()
get_labels(as_factor(x), values = "p")
# also add labels to non-labelled values
as_factor(x, add.non.labelled = TRUE) %>% head()
get_labels(as_factor(x, add.non.labelled = TRUE), values = "p")
# easily coerce specific variables in a data frame to factor
# and keep other variables, with their class preserved
as_factor(efc, e42dep, e16sex, c172code) %>% head()
# use select-helpers from dplyr-package
if (require("dplyr")) {
as_factor(efc, contains("cop"), c161sex:c175empl) %>% head()
}
}
#> Loading required package: sjmisc
#> Loading required package: magrittr
#> Error: 1 components of `...` were not used.
#>
#> We detected these problematic arguments:
#> * `add.non.labelled`
#>
#> Did you misspecify an argument?
```