Convert columns of data.frame to their correct types using table schema
dp_apply_schema(
dta,
resource,
convert_categories = c("no", "to_factor", "to_code"),
reorder = TRUE,
...
)Returns a copy of the input data.frame with columns modified to match the
types given in de table schema. When reorder = TRUE columns are put in the
same order as in the data resource with fields not in the data resource put
at the back of the data.frame.
a data.frame or data.table.
an object with the Data Resource of the data set.
how to handle columns for which the field
descriptor has a categories property. This should either be the
strings "no", "to_factor", "to_code", the name of a function or a function.
When equal to "no" the field is returned as is; when equal to "to_factor"
each column is transformed using dp_to_factor; when equal to
"to_code" each column is transformed using dp_to_code. In
other cased the function is called with the column as its first parameter and
warn = FALSE as its second argument. The result of this function call
is added to the resulting data set.
put the columns in the same order as the fields in the data resource.
additional arguments are passed on to the dp_to_<fieldtype>
functions (e.g. dp_to_number).
Converts each column in dta to the correct R-type using the type
information in the table schema. For example, if the original column type in
dta is a character vector and the table schema specifies that the field is
of type number, the column is converted to numeric using the decimal
separator and thousands separator specified in the field descriptor (or default values
for these if not).
This function calls conversion functions for each of the columns, see
dp_to_number, dp_to_boolean, dp_to_integer,
dp_to_date. dp_to_datetime, dp_to_yearmonth,
and dp_to_string.