Create input data.frame for subsequent calculation of descriptives — createInputForDescriptives • eatCodebook

Create a variable information data.frame from the GADSdat object. This input can be used to calculate the descriptives of the data via the calculateDescriptives function. See the details section for further information.

Usage

createInputForDescriptives(
  GADSdat,
  idExpr = "^ID",
  impExpr = c("IMPUTATION\\s+{0,1}[[:digit:]]{1,2}", "PV\\s+{0,1}[[:digit:]]{1,2}"),
  scaleExpr = "^Skala",
  itemExpr = "plausible|indikator",
  fakeItemExpr = "fake",
  nwExpr = "IDinClass",
  varNameSeparatorImp = "_",
  ncharSeparatorImp = 2,
  lastOccurrence = TRUE,
  groupSuffixImp = "imp",
  nCatsForOrdinal = c(2:5),
  nwVarNameSeparatorImp = "_",
  nwNcharSeparatorImp = 6,
  nwLastOccurrence = TRUE,
  verbose = FALSE
)

Arguments

GADSdat: Object of class GADSdat, created by import_spss from the eatGADS package, for example. Alternatively, a list of objects of class GADSdat
idExpr: Regular expression to identify ID variables from variable names (Note: for multiple expressions, i.e. if idExpr is a character vector of length > 1, at least one expression should match to identify the variable as ID variable). The use of a regular expression is due to the fact that the data records often contain not just one, but several identification variables, for example for pupils, teachers, schools, classes or federal states. Logically, no descriptive values are reported for identification variables. They must be specified here so that the subsequent calculateDescriptives function knows, so to speak, for which variables no descriptive values are to be calculated.
impExpr: Regular expression to identify imputed variables from variable labels in GADSdat object (Note: for multiple expressions, i.e. if impExpr is a character vector of length > 1, at least one expression should match to identify the variable as an imputed variable). Regular expressions are also used here, as several variables (each with different individual IDs) can be imputed.
scaleExpr: Regular expression to identify scale or fake scale variables from variable labels in GADSdat object (Note: for multiple expressions, i.e. if scaleExpr is a character vector of length > 1, at least one expression should match to identify the variable as a scale variable). Scales are defined when several items measure a common (latent) construct and there is also a variable that represents the scale value. The scale variable represents usually the averaged (or otherwise aggregated) value within a person across all items of this scale. Fake scales are defined when several items measure a common (latent) construct, but there is no additional variable that represents the scale value.
itemExpr: Regular expression to identify items which constitute a true scale from the variable labels in GADSdat object. Note: Only the regular expressions that identify the items must be entered here. The additional scale variables do not have to be specified. If several scales are defined in the data set (e.g. "self concept" and interest), no distinction needs to be made here as to which items belong to which scale. (This is done elsewhere.) Assume that the "self concept" is measured with the items SK_I1, SK_I2, SK_I3, and the scale variable is called SK_scale. Let us also assume that "interest" is measured with the items Int_I1, Int_I2, Int_I3, Int_I4, and that the scale variable is called Int_scale. Then it could be specified here: itemExpr = "I[1-4]{1}$"
fakeItemExpr: Regular expression to identify fake items which constitute a fake scale from the variable labels in GADSdat object. This works in the same way as with itemExpr.
nwExpr: Regular expression to identify network variables from variable labels in GADSdat object (Note: for multiple expressions, i.e. if nwExpr is a character vector of length > 1, at least one expression should match to identify the variable as a network variable)
varNameSeparatorImp: character sign to separate the "pooled" suffix from group name in group column. For example, if multiple imputed variables occur in the wide-format data.frame as pv_1, pv_2, pv_3, use "_". If no such sign exists in the data, i.e. if multiple imputations occur as pv1, pv2, pv3, instead of pv_1, pv_2, pv_3, or pv.1, pv.2, pv.3, use NA or NULL or "". In this case, you will have to specify the ncharSeparatorImp argument.
ncharSeparatorImp: Integer: only relevant if no varNameSeparatorImp exists, i.e. if multiple imputations occur as pv1, pv2, pv3, instead of pv_1, pv_2, pv_3, or pv.1, pv.2, pv.3. ncharSeparatorImp than specifies the number of character signs which should be trimmed to identify the common variable stem. If varNameSeparatorImp is not NA or NULL or "", ncharSeparatorImp will be ignored. For example, if multiple imputations occur as pv_1, pv_2, pv_3, use varNameSeparatorImp = "_". If multiple imputations occur as pv1, pv2, pv3, use varNameSeparatorImp = NULL and ncharSeparatorImp = 2. The first 2 signs of variables names (i.e., "pv") will be used to identify the imputed variables which belong to a common stem.
lastOccurrence: Logical: If varNameSeparatorImp occurrs multiple times within a string, lastOccurrence defines whether the last occurrence should be used for splitting
groupSuffixImp: tbd
nCatsForOrdinal: Numeric vector with number of categories considered for ordinal variables. Variables with number of categories as defined here are considered to be ordinal instead of nominal. If NULL, this rule will be ignored, and nominal/ordinal assignment is done in other ways
nwVarNameSeparatorImp: character sign to separate network variable names from network variable groups. For example, if network variables occur as friend_1, friend_2, ..., friend_12, use "_". If no such sign exists in the data, i.e. if network variable names occur as friend1, friend2, ..., friend12, use NA or NULL or "". In this case, you will have to specify the nwNcharSeparatorImp argument.
nwNcharSeparatorImp: Integer: only relevant if no nwVarNameSeparatorImp exists, i.e. if network variables occur as friend1, friend2, ..., friend12, instead of friend_1, friend_2, ..., friend_12. nwVcharSeparatorImp than specifies the number of character signs which should be trimmed to identify the common variable stem. If nwVarNameSeparatorImp is not NA or NULL or "", ncharSeparatorImp will be ignored. For example, if network variables occur as friend_1, friend_2, ..., friend_12, use nwVarNameSeparatorImp = "_". If network variables occur as friend1, friend2, ..., friend12, use nwVarNameSeparatorImp = NULL and nwNcharSeparatorImp = 6. The first 6 signs of variables names (i.e., "friend") will be used to identify the group.
nwLastOccurrence: Logical: If nwVarNameSeparatorImp occurrs multiple times within a string, nwLastOccurrence defines whether the last occurrence should be used for splitting
verbose: Should scale identification be reported?

Value

Returns a data.frame with variable information with following columns

varName The name of the variable as it occurs in the data
varLabel The label of the variable as it occurs in the GADSdat label sheet
format The variable format as displayed in the labels sheet of the GADSdat object
imp Logical: Whether or not the variable is imputed
type The type of the variable. Two possible entries, variable or scale
scale The scale level of the variable. Possible entries: nominal, ordinal, numeric. ID variables and character variables have missing entries in this column. Be cautious that 'ordinal' sometimes may be allocated erroneously. The resulting table should be exported to Excel for further checks.
group If the variable is part of a scale with several items, a common entry in the group column indicates that these variables belong together

Details

The eatCodebook package aims to create a human-readable pdf codebook from a GADSdat data base object. The codebook contains information about the variables used in the study, including their descriptive properties. Which descriptive properties are reported in the codebook depends, among other things, on the scale level of the variables. For example, the mean and standard deviation are reported for metric variables and frequency distributions for categorical variables. For non-imputed variables, the proportion of missing values is also given, and for scale variables, the number of items that make up the scale and the internal consistency of the scale are given. The codebook is created in several steps. In the first step, the createInputForDescriptives function is used to generate an auxiliary object from the database that contains information on what type of descriptive information is to be reported for which variable. The object created in this function is the basis for the calculateDescriptives function.

Examples

varInfo <- createInputForDescriptives(eatGADS::pisa, impExpr = "Plausible Value")