read_fwf_blaise {blaise}

Read a fixed width datafile using a blaise datamodel

Description

Use this function to read a fwf that is described by a blaise datamodel. If this function throws a warning, try using readr::problems() on the result, this will for instance show an error in the used locale.

Usage

read_fwf_blaise(
  datafile,
  modelfile,
  locale = readr::locale(),
  numbered_enum = TRUE,
  output = "data.frame"
)

Arguments

datafile

the fwf file containing the data

modelfile

the datamodel describing the data

locale

locale as specified with readr::locale(). Uses "." as default decimal separator. Can be used to change decimal separator, date_format, timezone, encoding, etc.

numbered_enum

use actual labels instead of numbers for enums that use non- standard numbering in the datamodel. With the default (TRUE) (Male (1), Female (2), Unknown (9)) will be read as a factor with labels (1, 2, 9). With FALSE it will be read as a factor (Male, Female, Unknown). beware that writing a dataframe read with FALSE will result in an enum with levels (1, 2, 3) unless overruled by an existing model, since R does not support custom numbering for factors.

output

Define which output to use. Either "data.frame" (default) or "LaF". LaF does not support Datetypes, so these are converted to character vectors. Using LaF, DUMMY variables also can't be ignored, these are read as empty character vectors. Using LaF basically takes over the parsing of the datamodel from LaF, since this is more robust and accepts more types of input.

Details

Handles the following types:

• STRING

• INTEGER

• REAL

• DATETYPE

• ENUM (if numbered it will be converted to a factor with the numbers as labels)

• custom types (same as a numbered ENUM)

If you want the numbered enums to be converted to their labels, this is possible by changing the "numbered_enum" parameter

Examples

model = "
DATAMODEL Test
FIELDS
A     : STRING[1]
B     : INTEGER[1]
C     : REAL[3,1]
D     : REAL[3]
E     : (Male, Female)
F     : 1..20
G     : 1.00..100.00
ENDMODEL
"
data =
"A12.3.121 1  1.00
B23.41.2210 20.20
C34.512.120100.00"

blafile = tempfile('testbla', fileext = '.bla')
writeLines(model, con = blafile)
datafile = tempfile('testdata', fileext = '.asc')
writeLines(data, con = datafile)

df = read_fwf_blaise(datafile, blafile)
unlink(blafile)
unlink(datafile)