Calculate Median Absolute Deviation (MAD)

The function mad produces MAD values in a tibble object.

Usage

mad_glu(data, constant = 1.4826)

Arguments

data

DataFrame object with column names "id", "time", and "gl", or numeric vector of glucose values.

constant

Numeric object which will be multipled by the MAD value. Defaults to 1.4826. Reasons for this default value can be seen in the details section of the documentation of r's base mad method

Value

If a data.frame object is passed, then a tibble object with two columns: subject id and corresponding MAD value is returned. If a vector of glucose values is passed, then a tibble object with just the MAD value is returned. as.numeric() can be wrapped around the latter to output just a numeric value.

Details

A tibble object with 1 row for each subject, a column for subject id and a column for MAD values is returned. NA glucose values are omitted from the calculation of the MAD.

MAD is calculated by taking the median of the difference of the glucose readings from their median and multiplying it by a scaling factor \(1.4826*median(|gl-median(gl)|)\), where gl is the list of Glucose measurements.

Author

David Buchanan, Marielle Hicban

Examples

data(example_data_1_subject)
mad_glu(example_data_1_subject)
#> # A tibble: 1 × 2
#>   id          MAD
#>   <fct>     <dbl>
#> 1 Subject 1  25.2

data(example_data_5_subject)
mad_glu(example_data_5_subject)
#> # A tibble: 5 × 2
#>   id          MAD
#>   <fct>     <dbl>
#> 1 Subject 1  25.2
#> 2 Subject 2  53.4
#> 3 Subject 3  31.1
#> 4 Subject 4  29.7
#> 5 Subject 5  53.4