The function sd_glu is a wrapper for the base function sd(). Output is a tibble object with subject id and sd values.
Arguments
- data
DataFrame object with column names "id", "time", and "gl", or numeric vector of glucose values.
Value
If a data.frame object is passed, then a tibble object with two columns: subject id and corresponding sd value is returned. If a vector of glucose values is passed, then a tibble object with just the sd 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 the sd values is returned. NA glucose values are omitted from the calculation of the sd.
Examples
data(example_data_1_subject)
sd_glu(example_data_1_subject)
#> # A tibble: 1 × 2
#> id SD
#> <fct> <dbl>
#> 1 Subject 1 33.3
data(example_data_5_subject)
sd_glu(example_data_5_subject)
#> # A tibble: 5 × 2
#> id SD
#> <fct> <dbl>
#> 1 Subject 1 33.3
#> 2 Subject 2 52.4
#> 3 Subject 3 44.8
#> 4 Subject 4 29.1
#> 5 Subject 5 58.6