Create a weight matrix

Expands a weight specification into a weight matrix to be used by locate_errors and replace_errors. Weights allow for "guiding" the error localization process, so that less reliable values/variables with lower weight are selected first. See details on the specification.

Usage

expand_weights(dat, weight = NULL, as.data.frame = FALSE, ...)

Arguments

dat

data.frame the data to be checked

weight

weight specification, see details.

as.data.frame

if TRUE a data.frame will be returned.

...

unused

Value

matrix or data.frame of same dimensions as dat

Details

If weight fine tuning is needed, a possible scenario is to generate a weight data.frame using expand_weights and adjust it before executing locate_errors() or replace_errors(). The following specifications for weight are supported:

• NULL: generates a weight matrix with 1's

• a named numeric, unmentioned columns will have weight 1

• an unnamed numeric with a length equal to ncol(dat)

• a data.frame with same number of rows as dat

• a matrix with same number of rows as dat

• Inf, NA weights are interpreted as variables that must not be changed. Inf weights perform much better than setting a weight to a large number.

See also

Other error finding: errorlocation-class, errors_removed(), locate_errors(), replace_errors()

Examples

dat <- read.csv(text=
"age,country
  49,     NL
  23,     DE
", strip.white=TRUE)

weight <- c(age = 2, country = 1)
expand_weights(dat, weight)
#>      age country
#> [1,]   2       1
#> [2,]   2       1

weight <- c(2, 1)
expand_weights(dat, weight, as.data.frame = TRUE)
#>   age country
#> 1   2       1
#> 2   2       1

# works too
weight <- c(country=5)
expand_weights(dat, weight)
#>      age country
#> [1,]   1       5
#> [2,]   1       5

# specify a per row weight for country
weight <- data.frame(country=c(1,5))
expand_weights(dat, weight)
#>      age country
#> [1,]   1       1
#> [2,]   1       5

# country should not be changed!
weight <- c(country = Inf)
expand_weights(dat, weight)
#>      age country
#> [1,]   1     Inf
#> [2,]   1     Inf